Discover the IHRDC Energy Glossary_beta

P chart

An attribute control chart that is used to plot the percentage of defective products produced by a process.

P f

Phenolphthalein filtrate alkalinity — the acid required to titrate mud filtrate to the phenolphthalein endpoint at pH 8.3.

P m

Phenolphthalein mud alkalinity — the same titration run on whole mud rather than on filtrate.

p rate

Rig shorthand for penetration rate, how fast the bit is making hole.

p wave

A compressional body wave in which particles move back and forth along the direction the wave travels.

P&A

Plug and abandon — to seal a well permanently with cement plugs and cut it off below surface.

P&ID

Piping and Instrumentation Diagram. A blueprint drawing that shows all the piping, instrumentation, and their respective specifications.

P-N junction

The area or point where an N-type material and a P-type material physically contact each other in a semiconductor.

P-N-P transistor

A bi-polar transistor that contains two P-type elements (poles) and one N-type element.

P-type material

A semiconductor material that has a lack of electrons.

PAC

Polyanionic cellulose: a cellulose derivative used in drilling fluids for filtration control, more tolerant of salt and contamination than CMC.

pack off

To seal the annulus around the drillstring, whether deliberately with a tool or accidentally by cuttings bridging.

packaging requirements

The protection, labeling and handling specifications a product must meet in transit.

packed-bed tower

A scrubber that uses a scrubbing liquid and packing to remove contaminants from a gas or vapor stream.

packer

A packer is a device that can be run into a wellbore that then expands to seal the wellbore.

packer flowmeter

A flowmeter with an inflatable packer that seals the annulus around it, forcing the whole flow through its spinner.

packer fluid

The fluid left in the annulus above a production packer for the life of the completion.

packing

In pumps and valves, a flexible, leak-resistant material (often tough, rope-like, impregnated with lubricant) that surrounds a valve stem or pump shaft to control leakage. In distillation, ceramic, carbon, or metallic saddles, rings, or other shaped pieces in a still column for intermingling liquid and vapor.

packing gland

The fitting that compresses packing rings around a rotating or reciprocating shaft to seal against leakage.

packing group

One of three categories established by the Department of Transportation to specify the packaging requirements for hazardous materials.

packing material

The material compressed to seal round a shaft or stem, or the internals of a column.

packing of grains

The distribution of grains and intergranular spaces (either empty or filled with cement or fine-grained matrix) in a sedimentary rock. Controlled by grain size, shape, and degree of compaction; determines the rock's bulk density.

packing ring

A ring of packing compressed to seal round a shaft or stem.

packstone

A carbonate rock of touching grains with mud between them, of intermediate reservoir quality.

pad

The prepared surface site from which one or more wells are drilled, built up from gravel, shell or timber.

paddle blender

A mixing tank with paddle agitators, used to hydrate and blend gels and slurries before they are pumped.

paddle mixer

A mixing tank with rotating paddles that keeps a treatment fluid or slurry dispersed and homogeneous.

paddle-type dryer

A type of rotary dryer that uses heat and rotating paddles to dry materials.

page tagging

Embedding code in pages so visits and events can be recorded.

paid leave

Time off with continued pay, whether for holiday, sickness or personal reasons.

paid search / pay-per-click (PPC)

Advertising charged when the ad is clicked rather than when it is shown.

paid-up lease

A lease whose delay rentals for the whole primary term are paid up front with the bonus, so no further payment is needed to keep it alive.

pair production

The conversion of a high-energy gamma ray into an electron-positron pair in the electric field of a nucleus.

paleoenvironment

The environment a sediment was deposited in.

paleogeographic

Concerning the geography of the past, reconstructed to predict where reservoir sand was deposited.

paleomagnetic

Relating to the ancient magnetic field recorded in rock.

paleontology

The scientific study of the history of life in the geologic past, involving the examination of both animal and plant fossils to identify geological strata, classify organisms, date layers of the Earth, and reconstruct past environments and climates.

paleoslope

A paleoslope is a regional slope that can be identified by the direction of paleocurrents. Paleocurrents are the direction of sediment flow, which can be used to identify the orientation of shorelines, continental slopes, and submarine canyons.

paleostress

Paleostress is a stress, or stresses, that occurred in the geologic past.

paleozoic

The geological era containing many of the world's oldest producing reservoirs.

palinspastic

Palinspastic reconstruction is a technique used by geologists to change the geometry found on a seismic section to the geometry that existed at some prior geologic time. It is considered to be successful when the geologist has been able to account for all the volume of rock in the reconstructed geologic section.

pallet

A portable platform for handling, storing, and moving materials and packages.

pallet jack

A forklift that is powered manually or by an electric motor, used when material must be moved from one location to another but not stacked.

paludal

Pertaining to a marsh, or to the sediments and organisms of one.

palustrine

Formed in a marsh or swamp. Used of sediment and of the plant material that goes on to become peat and coal.

palynology

The scientific study of pollen, spores, and other acid-insoluble organic plant fossils and microscopic fragments of larger organisms, used in stratigraphy, historical geology, and paleontology.

PAO

Poly-alpha-olefin — a synthetic base fluid polymerized from ethylene, used in early synthetic drilling fluids.

paper market

Trading in contracts settled financially, without any barrel changing hands.

para-xylene

The xylene isomer used to make polyester, the highest-value aromatic product.

parabolic dunes

Parabolic dunes are U-shaped sand ridges with their concave side toward the wind.

paraffin

A hydrocarbon whose carbon atoms are connected in a straight chain by single bonds. Heavier paraffins form a waxy substance found in some crude oils that often collects on tubing walls and restricts flow.

paraffin control

The measures taken to stop paraffin wax depositing in tubing and flowlines, or to remove it once it has.

paraffin inhibitor

A chemical injected continuously to keep wax crystals from growing and adhering as the crude cools.

paraffin scraper

A slickline tool with blades that cuts wax deposits from the tubing wall as it is run and pulled.

paraffin scratcher

A bladed slickline tool run to cut paraffin and soft wax off the inside of tubing.

paraffin-base crude oil

Crude rich in paraffin wax and low in asphaltic material.

paraffinic

Rich in straight-chain saturated hydrocarbons, which waxes readily on cooling.

paraffinic crude oil

Crude oil that contains a high proportion of paraffin.

paraffinic hydrocarbon

A saturated straight- or branched-chain hydrocarbon of formula CnH2n+2, also called an alkane.

paraffinic oil

A paraffinic oil is an oil based on n-alkanes.

paraffins and iso-paraffins

Saturated straight-chain and branched hydrocarbons; the branched forms carry higher octane.

paraformaldehyde

A solid formaldehyde polymer used as a preservative for starch, xanthan and guar.

paralic

Paralic facies are comprised of interfingering marine and continental sediments.

parallax

An optical illusion that can occur when an instrument with a pointer and scale is read from a position other than directly in front.

parallax (error)

The erroneous perception of the position of an object caused by the direction or position from which it is viewed.

parallel blade damper

A type of damper with parallel blades.

parallel circuit

A circuit that has two or more parallel paths through which current can flow.

parallel connection

A type of connection between racks or devices where data is transmitted many bits (often a word) at a time. The physical medium is usually a multi-conductor cable.

parallel flow

A fluid flow pattern in a heat exchanger such that two fluids flow past each other in the same direction.

parallel fold

A fold in which every layer keeps its original thickness measured perpendicular to the bedding.

parallel misalignment

Shaft axes parallel but offset, as distinct from angular misalignment.

parallel offset

The rerouting of pipe or tubing installed side by side or one over the other so that the configuration is neat and functional.

parallel resistivity

Formation resistivity measured with current flowing along the bedding planes rather than across them.

parallel-tap connector

A mechanical connector that is used for tapping a branch line off of a main conductor.

parallelogram

A four-sided, two-dimensional figure with two sets of parallel and equal sides; a rectangle, for example.

paramagnetic oxygen analyzer

An analyzer that measures the oxygen concentration of a gas mixture based on the principle that oxygen is attracted to a magnetic field.

parameter

A quantity in a reservoir or earth model that characterizes it, whether or not it varies with position or time.

parameters

The adjustable values inside a model that are set by fitting it to data rather than measured directly.

parametric

In electromagnetic surveying, pertaining to varying frequency while the source and receiver geometry is held fixed.

parasequence

A relatively conformable succession of beds bounded by marine flooding surfaces, recording one shallowing-upward cycle.

parasequence boundary

The marine flooding surface, or its correlative surface, that bounds a parasequence.

parasequence set

A group of genetically related parasequences forming a distinctive stacking pattern, bounded by major flooding surfaces.

paravanes

A paravane in a seismic acquisition system that includes a float, a frame suspended from the float, deflectors affixed to the frame, means for coupling a tow rope and usually attached navigation and depth equipment.

PARCOM

The Paris Commission, now merged into the Oslo and Paris Commission, OSPAR.

parking brake

The brake holding a vehicle stationary.

part

A subdivision of an article in the NEC.

partial completion

Partial completion occurs when the well only partially penetrates the formation.

partial condenser

A condenser that condenses most, but not all, of the vapors from a distillation tower.

partial differential equation

An equation in several variables and their rates of change, the form flow in porous media takes.

partial penetration

A well completed over only part of the productive interval, so flow must converge vertically to reach it.

participating interest

Each party's agreed share of the costs of exploration and production, and of the production that results.

participating or working interest

This term represents the oil and gas quantities or revenue available to the investors after all royalties have been paid. If the royalty is 15%, the Working Interest is 85% of production. The Working Interest owners are responsible for paying all costs. If there are multiple owners, they usually name one owner as the operator.

particle motion

The movement of the ground as a wave passes, which is what a geophone records.

particle size

The grain size distribution, which controls permeability and the design of sand control.

particle velocity

The speed of ground motion, as distinct from the speed the wave travels.

particle-plugging apparatus

A filtration cell fitted with a slotted or cored disc, used to run the particle-plugging test.

particle-plugging test

A filtration test measuring how well a fluid's solids bridge and seal a permeable or slotted medium, abbreviated PPT.

particle-size distribution

The proportion of a solids sample falling into each size range, expressed as a percentage of the total solids.

particulate matter

Solid carried in a fluid, which erodes valves and plugs exchangers.

particulates

Airborne contaminants in the form of small solid particles, dusts, mists, vapors, or gases, often left in exhaust gas after combustion or contained in gas or vapor streams.

partitioning

How a dissolved component distributes itself between two immiscible phases in contact at equilibrium.

partnership

A business owned jointly, where partners generally share liability.

parts per billion

A concentration of one part of a substance in a billion parts of the mixture, abbreviated ppb.

parts per million

A concentration of one part in a million parts, abbreviated ppm.

party

The field crew that acquires a geophysical survey, together with its equipment.

party chief

The person in overall charge of a seismic field crew and answerable for its output.

party manager

The crew member who runs the seismic party day to day, reporting to the party chief.

pascal

The SI unit of pressure, one newton per square meter, symbol Pa.

pass

One run of a logging tool through the interval, recording measurements as it moves.

passageway

A flow path through a component, whose blockage is often the whole fault.

passband

Passband is a specified range (or band) of frequencies through which a seismic signal may pass.

passing score

The threshold at which performance is deemed sufficient.

passive continental margin

A margin inside a plate, subsiding thermally and accumulating a thick sedimentary wedge.

passive margin

A continent-ocean boundary that lies within a single plate, where no convergence or seafloor spreading is taking place.

patch

A rectangular block of live receiver lines recorded for each shot in a land 3D survey.

patch reef

A small isolated reef body within a lagoon or shelf.

patent

A time-limited monopoly over an invention in exchange for disclosing it.

pathogen

Any disease-producing agent, especially a virus, bacterium or other microorganism.

pay

The component of a reservoir that contains economically producible hydrocarbons; the gross reservoir quality thickness above the hydrocarbon contact.

pay audit

A systematic review of pay data to find unjustified differences.

pay equity

Equal pay for work of equal value, irrespective of who does it.

pay for performance

Linking part of pay to measured results rather than to time in post.

payback period

How long until cumulative cash flow repays the original outlay.

payment for damages

Compensation paid to an owner of a property by the oil and gas company to cover losses or damages resulting from oil or gas operations.

payout

The point at which cumulative revenue has repaid all the capital and operating costs charged to a project.

PC

Personal computer, usually used to collect and arrange data into a manageable form.

PCC

Point of Common Coupling. An electrical junction where measurements of harmonic distortion are commonly made.

PCM (Professional Certified Marketer)

The AMA credential recognizing marketing competence in a chosen specialism.

PD meter

A positive displacement meter which measures volume of liquid.

pdc bits

Polycrystalline diamond compact bits, which shear rather than crush the rock.

PDM

Positive displacement motor: a downhole mud motor with a helical rotor turning inside an elastomer stator, driven by the circulating mud to turn the bit.

peak

The maximum positive excursion of a seismic wavelet, its crest.

peak amplitude

The largest amplitude in a wavelet or trace.

peak daily sendout

The maximum a storage facility or terminal can deliver in a day.

peak demand

The highest gas demand in any day in a year.

peak shaving

Meeting short peaks in gas demand from stored supply rather than from extra pipeline or production capacity.

peak value

The amount of voltage or current at the maximum positive or negative point on a sine wave.

peak voltage

The maximum positive or negative voltage in an AC cycle.

peak voltage (Vp)

The maximum voltage level measured from a zero reference point.

peak-to-peak value

The maximum change occurring during one cycle of alternating voltage or current, represented by the distance between the positive peak and the negative peak on a sine wave.

peak-to-peak voltage (Vp-p)

Voltage measured from the maximum point of a signal to its minimum point, usually twice the peak voltage.

PEF

Photoelectric factor: a log of a formation's photoelectric absorption, which depends on average atomic number and so identifies lithology.

peg-leg multiple

A short-path multiple whose downgoing and upgoing legs reflect at different interfaces, giving it an asymmetric path.

pelagic

Refers to the open ocean and the deposits or sediments that accumulate on the ocean floor, typically fine-grained, slowly deposited, and composed of biogenic material or wind-blown clays, far from land.

pendant

A box that is suspended from an electrical cable and houses a crane's operating controls to enable an operator to control the crane from the floor or ground.

pendant lines

Fixed-Length wire ropes that extend from the top of a boom to a mast to support the boom.

pendant-drop tensiometer

An instrument that derives interfacial tension from the shape of a drop hanging from a needle.

peneplains

Peneplains are low-relief plains that form by protracted fluvial erosion during times of extended tectonic stability.

penetration

A standard spec for most asphalts; a measure of hardness.

penetration rate

The speed at which the bit deepens the hole, usually quoted in feet or meters per hour, abbreviated ROP.

penetration rop

Rate of penetration, the speed at which the bit makes hole.

pennsylvanian

The late Carboniferous period, host to major North American reservoirs and coals.

pent

A prefix for the name of a hydrocarbon that has five carbon atoms.

pentane

An organic compound with the formula C5H12—an alkane with five carbon atoms. A hydrocarbon of the paraffin series that is a liquid at atmospheric conditions, usually separated during fractionation and sent to the refinery.

people analytics

Using workforce data to answer business questions about people.

People, Interests, Options, Criteria

The four elements of the Getting to Yes method, taken in that order.

peptization

The dispersal of an aggregated solid into a colloidal suspension, as when clay is broken down in water.

peptize

To disperse a solid, typically clay, into colloidal suspension.

peptized clay

Clay treated during manufacture with a dispersant so it hydrates and yields more readily.

peptizing agent

A chemical that promotes the dispersion of a solid into colloidal form.

percent

A value expressed in terms of the number of parts per one hundred.

percent change

The proportional difference between two values, the most misread figure in business reporting.

percent solids test

A test that indicates the amount of solids present in a solution.

percussion sidewall

A coring method firing hollow bullets into the borehole wall to recover samples.

percussion sidewall core

A core taken from the side of the borehole (perpendicular to it) by firing hollow, retrievable cylindrical bullets into the formation. The bullets remain connected to the sidewall coring gun by wires, and movement of the gun pulls the bullets from the borehole wall.

percussion sidewall coring

Recovering wall samples by firing hollow bullets into the formation.

perforate

To shoot holes through casing and cement into the formation, opening a flow path between reservoir and wellbore.

perforate overbalanced

To perforate with wellbore pressure higher than reservoir pressure, so fluid moves into the formation as the guns fire.

perforate underbalanced

To perforate with wellbore pressure below reservoir pressure, so the formation surges back and cleans the tunnels as they are made.

perforated completion

A completion producing through casing perforations rather than through an open hole or screen.

perforated interval

The depth range of a well that has been perforated and so is open to the reservoir.

perforated liner

A liner with holes or slots cut in it before it is run, giving inflow without any downhole perforating.

perforating

The operation of shooting holes through casing to establish communication with the formation.

perforating acid

Acid spotted across the interval before perforating, so the tunnels are cleaned as they are formed and surged back.

perforating charge

A shaped explosive charge whose conical metal liner collapses on detonation into a jet that cuts the perforation tunnel.

perforating depth control log

A gamma ray and casing collar log run before perforating to tie gun depth to the openhole log.

perforating fluid

The fluid placed across the interval before the guns are fired, chosen so it will not damage the new perforations.

perforating gun

The carrier assembly that conveys shaped charges into the well and fires them at the chosen depth.

perforating operation

The job of shooting holes through casing to connect the reservoir.

perforating overbalanced

Perforating with wellbore pressure above formation pressure.

perforation

A tunnel shot from the wellbore through casing and cement into the formation, through which fluids flow.

perforation cleanup

Removing debris and crushed rock from perforations to restore flow.

perforation density

The number of perforations shot per foot of interval, also called shot density.

perforation diameter

The size of the hole a charge makes, which affects flow and sand control.

perforation geometry

The size, phasing and density of perforations, which govern productivity.

perforation length

How far a perforation tunnel penetrates the formation, which affects productivity.

perforation penetration

How far a useable perforation tunnel reaches beyond the casing into the formation.

perforation phasing

The angular spacing of successive charges around the gun, so the tunnels are distributed around the wellbore.

perforation tunnel

The channel a shaped charge drives into the formation beyond the casing.

perforations

The holes shot through casing and cement to connect the reservoir to the wellbore.

perforator

The gun and charge assembly used to perforate.

performance appraisal

The periodic formal assessment, usually feeding pay and promotion decisions.

performance characteristic

A defining measure of how equipment behaves under given conditions.

performance curve

The plot of a machine's or well's output against its operating variable.

performance improvement plan

A documented plan with objectives and a deadline, used when performance is below standard.

performance management interview

The structured conversation reviewing performance against agreed objectives.

performance management system

The cycle of objectives, review and development through which performance is directed.

performance measure

A defined quantity tracked because it indicates whether an objective is being met.

performance monitoring framework

The structured set of measures, owners and review points that keeps a plan on track.

performance objective

A brief description of the intended outcome or result of training or a job; may also describe performance standards and equipment needed.

performance observation

See, Observation.

performance risk

The risk that a counterparty fails to deliver or lift as contracted.

performance specification

The required performance a component must demonstrate.

performance standard

The stated requirement a safety-critical barrier must meet, so it can be tested against something.

performance-based incentive

Reward contingent on measured results rather than on time served.

perimeter

The distance around a closed two-dimensional shape.

period

The time required for one complete cycle. The period equals 1/frequency.

periodic inspection

A scheduled check at longer than daily interval, usually requiring the item to be opened.

periodic maintenance

Work done on a fixed schedule rather than on condition or on failure.

periodogram

A plot of power against frequency, showing which periodicities are present in a dataset.

permafrost

Ground that stays frozen year round, lying beneath the shallow layer that thaws each summer in arctic regions.

permanent datum

The fixed elevation to which all depths in a well or area are referenced, commonly mean sea level or the kelly bushing.

permanent magnet

A piece of magnetic material made from ferromagnetic materials (such as iron, nickel, cobalt, rare-earth alloys, or lodestone) that retains its magnetism after being removed from a magnetic field.

permanent packer

A packer set to stay, removable only by milling.

permanent part-time

An ongoing role at reduced hours with the associated entitlements.

permanent well monitoring

Continuous measurement of downhole pressure, temperature or flow by gauges installed for the life of the completion.

permeability

A very important property of reservoir rocks that is a measure of their ability to transmit fluids (gas, oil, or water) through them. High permeability means fluid passes through the rock easily. Typically measured in darcies or millidarcies.

permeability estimation with nuclear magnetic resonance (NMR) logs

Permeability estimation from NMR logs uses the fact of the pore-water relaxation time being inversely related to the surface area-volume (S/V) ratio of the pore space. The NMR estimate of permeability is based on theoretical and core-based models that show that permeability increases with increasing porosity and pore size.

permeability measurement

Determining the rock's ability to transmit fluid, in the laboratory or from a well test.

permeability reservoir

Reservoir whose behavior is controlled by its permeability distribution.

permeability thickness

The product of permeability and net pay thickness, written kh, and the flow capacity a well test actually measures.

permeable

Having some permeability; the ability to transmit fluids like water or gas through interconnected pores and fractures.

permeable formation

Rock that will transmit fluid at useful rate.

permeable rock formation

Rock that will transmit fluid, and so can be produced or injected into.

permeable zone

An interval that will transmit fluid.

permeameter

Laboratory equipment used to measure a rock's permeability.

Permian Basin

The West Texas and New Mexico basin that is the largest oil-producing region in the United States.

permissible exposure

The concentration a worker may be exposed to over a stated period.

permissible exposure limit

The maximum amount of a chemical to which most workers can be repeatedly exposed without adverse effect, as specified by OSHA. Generally based on the Threshold Limit Values published by the ACGIH and typically based on a time-weighted average concentration over a normal 8-hour workday.

permissible exposure limit (PEL)

The regulatory exposure limit set by OSHA on the amount or concentration of a substance in the air, adopted from the threshold limit values set by the ACGIH.

permissive

A condition that must be true before a start is allowed, distinct from a trip that stops a running machine.

permit system

The employer's written procedure for preparing and issuing permits for entry and for returning the permit space to service following termination of entry.

permit-required confined space

A confined space whose atmosphere or contents make entry conditional on a written permit.

permit-required confined space (permit space)

A confined space that has one or more of the following characteristics:1. Contains or has a potential to contain a hazardous atmosphere;2. Contains a material that has the potential for engulfing an entrant;3. Has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section; or4. Contains any other recognized serious safety or health hazard.

permit-required confined space program (permit space program)

The employer's overall program for controlling, and, where appropriate, for protecting employees from, permit space hazards and for regulating employee entry into permit spaces.

permitting

Obtaining the consents required before construction or operation may begin.

permittivity

A material's ability to store charge in an applied electric field without conducting current.

perpendicular offset

The separation between source and receiver measured across the survey line rather than along it.

perpendicular resistivity

Formation resistivity measured with current flowing across the bedding planes.

persona development

Building representative profiles of target customers to guide design and messaging.

personal brand

The professional reputation someone carries, whether or not they manage it deliberately.

personal branding statement

A short statement of what one offers and to whom.

personal finance

Managing one's own income, spending, borrowing and saving.

personal protection equipment

Equipment or clothing designed to protect the user by preventing or reducing the effects of injuries.

personal protective equipment

Specialized clothing or equipment worn by an employee for protection against a hazard. General work clothes (e.g., uniforms, pants, shirts or blouses), not intended to function as protection against a hazard, are not considered to be personal protective equipment.

personal protective equipment (PPE)

Equipment that protects a worker from bodily injury.

personal statement [evidence]

As part of the knowledge evidence, the employee may provide a personal statement on a rare occasion when they cannot provide direct evidence. The assessor would confirm the content of the statement by questioning the employee. The account written by the employee describing how and why they did the task, which can:

• Prove knowledge and understanding
• Describe specific situations where no other evidence exists
• Explain other evidence where required.

perturbations

Small departures from a base condition, analyzed to test sensitivity.

petal basket flowmeter

A flowmeter whose hinged metal petals open to divert the whole flow through its spinner.

petrochemical

Relating to chemicals derived from hydrocarbon feedstock.

petrochemical building block

A basic chemical such as ethylene or benzene from which others are made.

petrochemical company

A business converting hydrocarbons into chemicals and polymers.

petrochemical complex

The integrated set of plants converting hydrocarbon feedstock into chemicals and polymers.

petrochemical consulting company

A firm advising on petrochemical markets, technology and projects.

petrochemical feedstock

The hydrocarbon stream a chemical plant converts, usually ethane or naphtha.

petrochemical industry

The sector converting hydrocarbon feedstock into chemicals and polymers.

petrochemical market

The market for chemicals and polymers made from hydrocarbons.

petrochemical plant

A facility converting hydrocarbon feedstock into chemicals and polymers.

petrochemical producer

A company manufacturing petrochemicals.

petrochemical product

A chemical or polymer made from hydrocarbon feedstock.

petrochemical project

A development building capacity to convert hydrocarbons into chemicals.

petrochemical value chain

The sequence from feedstock through building blocks and intermediates to finished polymers.

petrographic

Pertaining to the detailed description of rocks, particularly under the microscope in thin section.

petrography

A branch of petrology that focuses on the detailed descriptions of rocks.

Petroland / Major Corporation (negotiation case)

The two sides of the negotiation role play, a government and an international oil company.

petroleum

A material containing hydrocarbons that appears under the surface of some areas of the earth.

petroleum accumulation

Hydrocarbons gathered and retained in a trap.

petroleum company

A business engaged in finding, producing or processing oil and gas.

petroleum engineer

The engineer responsible for drilling, completing and producing wells.

petroleum engineering

The discipline of getting hydrocarbons out of the reservoir and to surface economically.

petroleum exploration

The search for undiscovered accumulations of oil and gas.

petroleum fraction

A cut of the crude boiling range with defined limits.

petroleum gas

Gaseous hydrocarbons produced with or instead of oil.

petroleum geochemistry

The chemistry of source rocks and oils, used to establish origin and maturity.

petroleum geologist

The geologist working on exploration and reservoir description.

petroleum geology

The study of how hydrocarbons form, migrate and accumulate in the subsurface.

petroleum industry

The sector finding, producing, processing and selling oil and gas.

Petroleum Industry Act (PIA) 2021

Nigeria's overhaul of petroleum law, restructuring the regulators, fiscal terms and host community obligations.

petroleum initially in place

The total quantity of petroleum estimated to exist originally in naturally occurring reservoirs.

petroleum measurement

The discipline of quantifying oil and gas for custody, governed by published standards rather than local practice.

Petroleum Mining Lease (PML)

The production right created by the Act, granted on a commercial discovery.

petroleum potential

The prospect a region holds for commercial hydrocarbons.

petroleum product market

The market in which refined products are bought and sold.

petroleum project economics

Evaluating whether an oil or gas investment earns enough to justify its cost and risk.

Petroleum Prospecting Licence (PPL)

The exploration right created by the Act, with defined duration and work obligations.

petroleum province

A region sharing a petroleum system and therefore a common exploration model.

petroleum reservoir

The rock volume holding a producible accumulation of oil or gas.

petroleum resource

The total quantity estimated to exist, whether or not it is currently recoverable.

petroleum system

A mature source rock together with the migration paths, reservoirs, seals and traps that its hydrocarbons occupy.

petroleum systems

A petroleum system is a conceptual framework that defines the essential geologic elements and natural processes that generate and cause the accumulation and preservation of hydrocarbons. The system consists of five essential components: a source rock, a reservoir rock, a seal (or cap) rock, a trap and a migration pathway. Understanding these components and processes can assist with the search and production of petroleum.

petroleum systems modeling

Numerical reconstruction of a basin's burial, thermal and migration history to predict where hydrocarbons were generated and where they went.

petroleum tax

The tax levied specifically on petroleum production and profit.

petrologic

Pertaining to petrology, the study of rocks and their origin, at a scale visible without a microscope.

petrology

The study of rocks, including their occurrence, origin, history, structure, texture, and composition.

petronas

Malaysia's national oil company.

petrophysical analysis

Converting log measurements into porosity, saturation and lithology.

petrophysical interpretation

Deriving porosity, saturation and lithology from log measurements.

petrophysical model

The set of equations and assumptions used to turn log measurements into porosity, saturation and lithology.

petrophysical property

A rock property relating log response to porosity, saturation or lithology.

petrophysical rock type

A grouping of rock that shares the same pore geometry and so the same relationship between porosity, permeability and saturation.

petrophysical software

The applications used to interpret logs and compute porosity and saturation.

petrophysicist

A specialist who practices and has expertise in petrophysics.

petrophysics

The study of the physical, electrical, and mechanical properties and rock/fluid interactions of petroleum systems.

petrophysics, petrophysical

Petrophysics is the study of the properties (physical, electrical, and mechanical) and the rock/fluid interactions of petroleum systems.

pH

A figure expressing the acidity or alkalinity of a solution on a logarithmic scale from 0 to 14, where 7 is neutral, lower values are more acid, and higher values are more alkaline.

pH scale

A scale or method used to measure and indicate the relative acidity or alkalinity of a solution.

pH test

The rig measurement of mud and filtrate acidity or alkalinity, made with a meter or paper strip to API procedure.

Phanerozoic time

Phanerozoic time refers to the current geological eon, spanning from around 541 million years ago to the present, characterized by an abundance of visible fossils due to the widespread presence of organisms with hard body parts like shells and bones. This signifies a period of diverse and complex life on Earth. The word "Phanerozoic" means "visible life."

phantom

A horizon carried across a gap in the data as the interpreter's estimate of where the event would run.

phase

The degree to which AC waveforms are in step or out of step with each other, measured in degrees from the beginning of a cycle. Also, a state in which matter exists: gas, liquid, or solid.

phase change

A change in a state of matter, such as from a solid to liquid or from a liquid to a vapour.

phase current

The current that flows through the coils or resistors in a three-phase system.

phase current or voltage

The value of current or voltage produced inside an AC Generator.

phase diagram

The plot of phase state against pressure and temperature, which says whether a reservoir is oil, gas or condensate.

phase difference

Phase difference is the difference in phase angle between two sinusoids or phasors.

phase redistribution

The pressure change caused by gas rising and liquid falling in a wellbore after a surface shut-in.

phase shift

The lag in phase of an electromagnetic wave measured between two receivers after it has passed through the formation.

phase shift oscillator

An RC oscillator that produces a sine wave output.

phase velocity

The speed at which a single frequency component, or a crest or trough, travels through a medium.

phase velocity log

A log of how fast an individual phase — water, oil or gas — is moving in a producing well.

phase voltage

The voltage that is applied across the resistors or induced in the coils of a three-phase system.

phase-shift resistivity

Formation resistivity computed from the phase difference of an electromagnetic wave between two receivers.

phased retirement

A gradual reduction in hours before full retirement, preserving knowledge transfer.

phases of AI

The progression from narrow task-specific systems toward more general capability.

phasing

The phase relationship of a wavelet, which decides whether a reflection appears as peak or trough.

phenol

An aromatic ring with a hydroxyl group, corrosive to skin and a chemical feedstock.

phenolphthalein

A pH indicator, colorless below pH 8.3 and pink to red above it.

phishing

Fraudulent messages designed to induce someone to disclose credentials or run malware.

phishing simulation

A controlled fake phishing campaign used to measure and improve staff response.

PHMSA (Pipeline and Hazardous Materials Safety Administration)

The United States regulator for pipeline safety and hazardous materials transport.

Phoenix libraries

phosphate salt

A salt of phosphoric or phosphorous acid, used in muds as a thinner and to precipitate calcium.

photoconductive light

A light-sensitive diode that is used to control circuits that have an externally applied potential by sensing changes in light intensity. Also called a photodiode.

photoelectric

The log measurement responding to the average atomic number, used to identify lithology.

photoelectric absorption

Photoelectric absorption is the interaction of a gamma photon with matter in which the incident photon is completely absorbed, giving up all its energy by displacing and accelerating an inner shell electron.

photoelectric effect

A gamma ray interaction in which the gamma ray is fully absorbed by a bound electron. If the transferred energy exceeds the binding energy, the electron is ejected and replaced, emitting a characteristic X-ray dependent on atomic number. It occurs with highest probability at low gamma ray energy and high atomic number. The photoelectric effect is the principle behind the PEF log, which identifies lithology.

photoelectric effect, photoelectric factor

The photoelectric factor is a gamma ray interaction in which the gamma ray is fully absorbed by a bound electron. If the energy transferred exceeds the binding energy to the atom, the electron will be ejected. Normally, the ejected electron will be replaced within the material and a characteristic X-ray will be emitted with an energy that is dependent on the atomic number of the material. The highest probability for this effect occurs at low gamma ray energy and in a material of high atomic number. The photoelectric effect (PEF, Pe) is the principle behind the photoelectric (PEF) log, which identifies lithology.

photoelectric log

The photoelectric effect is a gamma ray interaction in which the gamma ray is fully absorbed by a bound electron. If the energy transferred exceeds the binding energy to the atom, the electron will be ejected. Normally, the ejected electron will be replaced within the material and a characteristic X-ray will be emitted with an energy that is dependent on the atomic number of the material. The photoelectric effect is the principle behind the photoelectric log, which identifies lithology.

photometer

An instrument that measures the absorption of electromagnetic radiation.

photon log

A cased hole density log using a gamma ray source and detector to see the material around the completion.

photovoltaic cell

A semiconductor converting light directly to electricity, with no moving parts and no fuel.

photovoltaic light

A light-sensitive diode that uses the energy in light to produce a voltage that is the sole voltage source for its circuit.

PHPA

Partially hydrolysed polyacrylamide — an anionic copolymer used to encapsulate cuttings and inhibit shale.

PHPA mud

A water-base mud built around partially hydrolysed polyacrylamide for shale inhibition and cuttings encapsulation.

PHR (Professional in Human Resources)

The HRCI credential for HR professionals working at operational level.

phreatic zone

The phreatic zone, also known as the saturated zone or zone of saturation, is the part of an aquifer below the water table where the soil or rock is saturated with water. This is a reducing environment which preserves organic matter. Iron is also preserved as drab-colored ferrous oxides or pyrites.

physical hazard

A chemical or material that has the potential to catch fire, explode, or undergo some other violent reaction, including combustible liquids, compressed gases, explosives, flammables, organic peroxides, oxidizers, pyrophorics, unstable (reactive) substances, and water-reactive substances.

physical layer

The lowest level of network protocol that governs the physical specifications for the mechanical and electrical interface.

physical market

Trading in actual cargoes that must be loaded, shipped and delivered.

physical security

Controls protecting premises and equipment, without which logical controls can be bypassed.

physics-informed ai

Models constrained during training to respect known physical laws, so their predictions cannot violate them.

pi (π)

A Greek letter designating the ratio between a circle's circumference and its diameter; the constant approximately equal to 3.14159.

pi filter primary winding

The transformer winding that is connected to the incoming power.

PIA 2021 (Petroleum Industry Act)

Nigeria's Petroleum Industry Act, which replaced the previous regime for licensing, fiscal terms and regulation.

PIC box

An interface adapter that mounts external to a standard PC and allows the PC to communicate on Allen-Bradley's Data Highway networks.

pick

To select and follow a specific reflection or marker through seismic or log data.

pick-up current

The amount of current needed to reposition a relay element.

Pickett plot

A Pickett plot is a visual representation of the Archie equation. It is a graphical technique for estimating the water saturation. A set of porosities and their corresponding resistivities taken from well logs and 2×4 cycle log-log paper are required. A Pickett plot also allows the estimation of the input parameters to the Archie equation.

pickle

To circulate a weak inhibited acid through tubing or coiled tubing to strip scale, rust and mill scale from the inside.

pickling fluid

The inhibited acid circulated through a string to dissolve rust, scale and mill debris from its inside before a treatment.

pickup

The depth at which the logging tool string is lifted off bottom to begin the recorded pass.

pickup current

The amount of current needed to close relay contacts.

pictogram

The standard hazard symbol on a chemical label.

pictorial drawing

A type of drawing that is made from an angle so that several sides of an object are visible in a single view.

PID control

A control algorithm that includes proportional, integral, and derivative factors.

pie graph

A circular graph that is typically used to compare the various parts of a whole to each other and to the whole; also called a pie chart.

piezoelectric

Piezoelectric refers to an electrical charge that accumulates in certain solid materials-such as crystals, certain ceramics, and biological matter (such as bone, DNA, and various proteins)-in response to an applied mechanical stress.

piezoelectric crystal

A piezoelectric crystal is a crystal, such as quartz, that produces a potential difference across its opposite faces when under mechanical stress.

piezoelectric properties

Piezoelectric property refers to an electrical charge that accumulates in certain solid materials-such as crystals, certain ceramics, and biological matter (such as bone, DNA, and various proteins)-in response to an applied mechanical stress.

piezoelectric transducer

A device that converts the deformation of solid materials into electrical charges, which other instruments can then interpret.

piezoelectricity, piezoelectric

Piezoelectricity is the electric charge that accumulates in certain solid materials in response to applied mechanical stress. Piezoelectricity means electricity resulting from pressure.

pig

A device that is propelled into a pipeline to clean out accumulated residues or foreign matter.

pig launcher

A device that uses fluid pressure to propel a “pig” into a pipeline.

pig receiver

The barrel a pipeline pig is caught in, isolated and depressured before opening.

pig run

One passage of a pig through a pipeline, for cleaning, batching or inspection.

pig trap

A device used to catch a “pig.”

pigging

Running a pig through a pipeline to sweep out liquids and debris, or to inspect the wall.

pigtail

A short, added piece of wire, commonly used to extend or connect wires in a box.

pill

A small volume of specially treated fluid, under about 200 bbl, spotted downhole to do a job the main mud cannot.

pilot

A small spring-loaded relief valve attached to a piston relief valve to control the pressure on top of the piston.

pilot device

A device that can be activated by specific changes in a process and used in a motor controller to perform a variety of functions, such as sending an alarm.

pilot exciter

A small self-excited DC generator used in some excitation systems as a separate source of DC power for a main exciter, supplying direct current to the electromagnet in the stator of a DC exciter.

pilot mill

A mill with a central stinger that enters the bore of the fish, keeping the cutting face centered on it.

pilot test

A small-scale test on a mud sample, scaled to the pit volume, run to check how a proposed treatment will behave before it is mixed.

pilot to enterprise scale

The step at which most digital initiatives fail: moving from a working trial to routine use everywhere.

pilot tube

A device, consisting of an inner tube and an outer tube, that can be used to measure pressure in a fan system.

pilot valve

A small valve whose action controls a larger one.

pilot wire relay

A relay that compares three-phase current at the ends of a short transmission line and operates if the currents are unequal.

pilot wires

Conducting wires, similar to telephone lines, that connect pilot wire relays.

pilot-actuated relief valve

A relief valve whose main valve is opened by a pilot, giving tighter setting at high pressure.

pilot-operated regulator

A regulator whose main valve is positioned by a small, accurate pilot regulator rather than directly by the sensed pressure.

pilot-operated valve

A type of safety relief valve that has a separate sensing component (the pilot) to control the operation of the main valve.

pin

The male, externally threaded end of a tubular connection, which makes up into a box.

pin fastener

A non-threaded fastener that is a piece of solid material used to join items together.

pinch out

The lateral thinning of a bed to zero thickness against another surface.

pinch valve

A valve that is closed by squeezing, or pinching, a tube.

pinch-off voltage

In JFET's, a critical magnitude of gate potential that causes the depletion region to expand sufficiently to close off the channel entirely, causing current flow to cease.

pinion

The smaller gear in a pair of gears.

pinion shaft

The small input gear shaft of a gear operator or compressor, driving the larger gear it meshes with.

pink-collar job

Work historically dominated by women, often undervalued in pay terms.

pinnacle reef

A steep isolated reef build-up, a small target with excellent reservoir quality.

pipe cutter

A tool cutting pipe squarely without a saw.

pipe diameter

The bore of a pipe, which sets velocity and therefore both pressure loss and erosion.

pipe dope

A grease loaded with fine metal particles, applied to threads to prevent galling and seal the thread roots.

pipe fitting

A component joining, branching or changing the direction of pipe.

pipe heat exchanger

Exchanger built from pipe rather than a tube bundle, used for small duties and dirty service.

pipe heavy

The condition in snubbing when the string's weight exceeds the well pressure force acting to push it out.

pipe light

The condition in snubbing when well pressure acting on the pipe exceeds its weight, so it must be forced into the well.

pipe prover

A calibrated length of pipe used to prove a meter by displacing a known volume through it.

pipe rack

The elevated framework on which tubulars are stored horizontally at the rig before being picked up.

pipe ram

A blowout preventer ram with a half-circle face sized to close around a particular pipe size and seal the annulus.

pipe stretch

The elastic elongation of a string under its own weight and any applied pull.

pipe trip

A round trip of the drillstring out of and back into the hole.

pipeline

A system of pipe, pumps or compressors and stations that moves crude oil, gas or products between points.

pipeline automation

Remote monitoring and control of pipeline flow, pressure and valves.

pipeline capacity

The volume of gas which is needed to maintain a full pipeline.

pipeline company

A business owning and operating pipelines, usually earning a regulated or contracted tariff.

pipeline construction

The work of building a pipeline, from right of way through welding to commissioning.

pipeline design

Sizing and routing a pipeline for the flow, pressure and terrain it must handle.

pipeline gas

Gas processed dry enough and clean enough to meet the transmission line's specification without dropping liquids.

pipeline interconnection

The point where two pipeline systems join and gas or liquid can transfer.

pipeline oil

Treated crude whose water and sediment content meets the pipeline's specification for acceptance.

pipeline operation

Running a pipeline: scheduling, pressure control, batching and integrity.

pipeline patrol

A routine inspection along a pipeline route, on foot, by vehicle or from the air, looking for leaks, washouts and encroachment.

pipeline pressure

The pressure a sales pipeline holds, which the plant must exceed to deliver into it.

pipeline project

A development to build new pipeline capacity.

pipeline service

The transport service a pipeline sells, firm or interruptible.

pipeline system

The network of line pipe, compression, valves and metering forming a transport system.

pipeline tariff

The published charge for moving gas or liquids through a pipeline.

pipeline transportation

Moving hydrocarbons by pipe, the cheapest bulk method over land.

pipeline vandalism

Deliberate damage to pipelines, whether for theft, protest or extortion.

pipette

A laboratory instrument transferring a measured volume of liquid.

piping system

The connected pipe, fittings and valves carrying a fluid.

piping system diagram

A diagram representing the major components and pieces of equipment in a piping system; includes flow diagrams and piping and instrumentation diagrams (P and IDs).

piston

In a pilot-operated relief valve, a short cylinder used to close the path between inlet and outlet. In a reciprocating compressor, the device that causes gas compression within the cylinder.

piston actuator

An actuator using pressure on a piston to move a valve.

piston cylinder

The cylinder a piston works in.

piston effect

The use of line pressure acting on a floating valve seat to push it against the closure member and complete the seal.

piston pump

A reciprocating pump that uses a piston to move fluid.

piston ring

The ring sealing a piston to its cylinder wall.

piston rod

The rod transmitting force from a piston to the crosshead or load.

PIT

Pressure integrity test: pressuring up below a new casing shoe to confirm formation and cement will hold the pressures the next hole section needs.

pitch

In fasteners, the distance from one thread crest to the next, normally expressed as threads per inch. In fans, the inclination or angle of the blades. In refining, leftover material at the bottom of a vacuum distillation tower.

pitch-and-lead

Two thread dimensions: pitch is the distance between adjacent threads, lead is the axial travel in one turn.

Pitman arm

A steel rod that connects the crank arm to the equalizer on the beam.

Pitot tube

A bent tube inserted into a flow stream that measures the difference between total and static pressure, from which velocity and flow rate follow.

pitting

Localized corrosion that eats deep, isolated cavities into metal while leaving the surrounding surface intact.

PK pneumatic tester

An instrument using dead weight to test the accuracy of the differential.

placard

A diamond-shaped sign that is typically attached to bulk hazardous materials packaging to identify the contents of the packaging and the risks associated with the material.

plagioclase

Plagioclase is a form of feldspar consisting of aluminosilicates of sodium and/or calcium, which is common in igneous rocks and typically appears white.

plan view

Any of several types of top-view drawings of a budding, such as a site plan, a floor plan, and a foundation plan.

Plan-Do-Check-Act cycle

The iterative improvement loop underlying most quality methods.

planarity

Planarity occurs when at least two points in space define a plane.

plane table

A tripod-mounted drawing board used with an alidade to plot a map directly in the field as the survey is made.

plane wave

A wave far enough from its source that its wavefront is effectively flat over the distance being considered.

plankton

Small organisms drifting in the surface waters of lakes and seas, the principal source material for oil-prone kerogen.

planktonic

Floating in the water column, said of the organisms whose remains date open-marine sediment.

planned shutdown

A normal furnace shutdown that is scheduled for reasons such as maintenance and repairs.

planning

Establishing scope, schedule, cost and the approach to delivering them.

plant

To set a geophone firmly into the ground so it moves with the earth.

plant inlet

Where gas enters the facility, and the custody and measurement point.

plant system

A group of connected components that function together to carry out a specific task.

plan–Source–Tender–Manage–Close

The five stages of that cycle, used as the framework for controls and assurance.

plastic

Said of a material that deforms permanently under stress without breaking.

plastic deformation

Permanent change of shape under load, with no fracture and no return to the original dimensions.

plastic electrical tape

A plastic or vinyl insulating tape that can withstand higher voltages than rubber tape and friction tape.

plastic fluid

A fluid that will not flow at all until a finite shear stress is applied, and then flows with a viscosity independent of shear rate.

plastic viscosity

The Bingham plastic model's slope term, the part of a mud's flow resistance caused by solids and by the viscosity of the base fluid.

plasticity

Plasticity is the quality of being easily shaped, or moulded.

plate boundary

The line along which two lithospheric plates meet and move relative to each other.

plate out

To deposit and remain as a coating on a rock face or perforation tunnel rather than being carried away.

plate tectonics

The theory that the Earth's rigid outer shell is divided into plates whose movement over the asthenosphere produces its major geological features.

plate valve

A suction or discharge valve that uses a flat plate which lifts and seats by differential pressure to control gas flow. This valve is used for high pressure compression requirements.

plateau

An extensive, nearly level upland standing well above the surrounding country and bounded by steep slopes.

plateau production

The period a field holds its design rate before decline sets in.

plateau rate

The production rate a field holds before decline begins.

platform

A broad, gently dipping area of sedimentary cover resting on the stable basement of a craton.

Platts Market on Close (MOC)

The structured window in which bids and offers are made publicly and the day's assessment is set.

play

An area in which hydrocarbon accumulations or prospects with similar characteristics occur, such as the Lower Tertiary play in the deepwater Gulf of Mexico or the Marcellus play in the eastern United States.

play back

To regenerate a log from the recorded digital data after the survey, at a different scale or with different processing.

play or prospect

A play consists of one or more geologically related prospects, and a prospect is a potential trap that must be evaluated by drilling.

play, petroleum play

A petroleum play, or simply a play, is a group of oil fields or prospects in the same region that are controlled by the same set of geological circumstances.[1] The term is widely and heavily used in the entire realm of exploitation of hydrocarbon-based resources.

playas

A playa is a flat, dry, and vegetation-free area in a desert basin that is at the lowest point.

PLC

Programmable Logic Controller. A common type of controller well-suited for discrete logic decisions, used to operate sections of automated systems typically involving dozens of inputs and outputs, including variable speed drives.

plenum

See Inlet box.

pliers

A hand tool for gripping.

pliocene

The geological epoch whose sediments host many shallow producing reservoirs.

PLT

Production logging tool: a string of sensors run in a flowing well to measure the rate, phase and temperature of fluid entering at each interval.

plug and abandon

To seal a well permanently with cement plugs and cut it off below surface, abbreviated P&A.

plug flow

Flow with a flat velocity profile across the pipe, the whole fluid advancing as a single plug.

plug fuse

A type of fuse that is held in position by a screw thread contact.

plug sample

A small cylinder cut from core for measurement.

plug valve

A valve whose flow control component is a plug with an opening through it. The valve is opened and closed by rotating the plug inside the valve body, providing a straight-through flow pattern. Designed for throttling.

plugged perforation

A perforation blocked by debris or scale and no longer contributing.

plugging material

A solid or gel added to a fluid to block a permeable zone and stop losses into it.

plumb

A surface or an object that is determined to be perfectly vertical.

plumb bob

A weight attached to the end of a reel of flexible metal measuring tape, lowered into a liquid container to make innage or outage measurements. A type of direct level measurement device.

plunge

The angle a linear feature makes with the horizontal, measured in the vertical plane that contains it.

plunger

A closely fitted hollow tubular piston operating in the barrel for displacing well fluid.

plunger element

A relay element in which a magnetic field attracts a plunger into a coil to close contacts.

plunger lift

An artificial lift method in which a free piston travels the tubing, carrying accumulated liquid ahead of it to surface.

plunger overtravel

The condition in which the downhole pump plunger strokes further than the polished rod does at surface.

plunger pump

A reciprocating pump that uses a plunger to move fluid.

PMI (Project Management Institute)

The Project Management Institute, which sets the dominant project management standards and credentials.

PMI Code of Ethics and Professional Conduct

The professional standard of responsibility, respect, fairness and honesty for project practitioners.

PMI-ACP (Agile Certified Practitioner)

The PMI credential for practitioners working in agile environments.

PMI-PBA (Professional in Business Analysis)

The PMI credential for business analysis practitioners.

pneumatic actuator

An actuator driven by air pressure, which fails to a known position when air is lost.

pneumatic control

Control using air pressure as the signal and the motive power.

pneumatic control system

A safety control system that signals a pilot to shut off fuel supply to the prime mover, shutting down the compressor package.

pneumatic drill

A power drill that is operated by compressed air or gas.

pneumatic gauge

Gauge worked by air pressure, used where electrical instruments are not permitted.

pneumatic signal

A control signal carried as air pressure, traditionally three to fifteen pounds.

pneumatic tool

A hand tool powered by compressed air.

pocket mandrel

A tubing component holding a gas lift valve in a retrievable side pocket.

point (data point)

Point (Data Point) Any item associated with a process control loop and related to other monitoring and control devices on the loop (for example, analog input, digital output, control points, etc.)

point bar

The arcuate sand body built on the inner bank of a river meander as the channel migrates across its floodplain.

point counting

Point counting is a statistical technique. It involves looking at a large number of points on the slide, recording exactly what is seen at each point and then assembling a description from all the information recorded.

point of departure (POD)

The point in a thickening-time test where the slurry's consistency starts to rise from its baseline, abbreviated POD.

point-and-click

The navigation method used in graphical user interfaces: a mouse or trackball cursor is positioned on an icon or object, then a button is pressed (making a "click" sound) to select the object or initiate a program.

point-to-point

A type of network topology in which all of the devices on the network are directly connected to each other.

poise

The centimetre-gram-second unit of dynamic viscosity, symbol P; oilfield fluids are usually quoted in centipoise.

poisoned catalyst

A catalyst that can no longer function properly.

poisson

Poisson's ratio, relating lateral to axial strain and used in rock mechanics.

Poisson distribution

The discrete distribution of how many independent events occur in a fixed interval, with mean and variance both equal to the expected count.

Poisson's ratio

The negative ratio of transverse to axial strain. When a material is compressed in one direction, it tends to expand in the other two directions perpendicular to the direction of compression.

Poisson's ratio

The negative ratio of transverse to axial strain. When a material is compressed in one direction, it tends to expand in the other two directions perpendicular to the direction of compression.

polar

Said of a molecule whose bonding electrons are unevenly shared, leaving partial charges at either end.

polar compound

A compound built of molecules carrying partial or full electrical charges.

polarity

A pair of electric charges of equal magnitude but opposite sign, separated by some (usually small) distance.

polarity standard

The SEG convention fixing how a positive reflection coefficient is displayed on zero-phase seismic data.

polarity switch

A control on an analog test instrument that is used to select either positive or negative DC readings.

polarization analysis

This is an analysis applied to S-waves (a transverse wave) that determines the geometrical orientation of the wave motion.

polarization horn

A sharp spike on a propagation resistivity log at a bed boundary, caused by charge accumulating at the contrast between layers.

polarization horns

Polarization horns are the effect on a propagation resistivity of charge build-up at the boundary between two formation layers with different dielectric properties.

polarization index

The ratio of a ten-minute megohmmeter reading taken across the windings of an AC generator to a one-minute megohmmeter reading; the index indicates the condition of a generator's insulation.

polarization time

The polarization time (TW) in NMR logging is the time between the cessation of measurement of one echo train and the beginning of measurement of the next echo train.

polarized light

Polarized light waves are light waves in which the vibrations occur in a single plane.

pole

That portion of a device that is associated exclusively with one electrically separated conducting path of the main circuit or device.

pole pieces

The parts of a salient-pole rotor around which windings are wrapped.

poles

The two areas on a magnet where the magnetic force is greatest.

police power

A state's legitimate authority to regulate, which can shade into uncompensated taking.

policy incentive

A subsidy, credit or mandate that changes project economics enough to make investment happen.

polished joint

A completion component with a machined and polished external or internal surface, so a seal assembly can seal against it.

polished rod

The top rod in a sucker rod string, made of highly polished and tempered steel.

polished rod load

The load carried at the polished rod, from which the whole rod string's condition is inferred.

political optics

How a decision will be perceived politically, which can outweigh its technical merit.

political risk

The risk that government action rather than market or technical failure destroys project value.

polling

An electronic signal that causes the EFC to send specified data.

pollutant

A substance that is able to change the environment in a way that causes harm to plants, animals, or people when it is present in large enough amounts.

pollution

A discharge of harmful material into the environment above the limits set by regulatory agencies such as the Environmental Protection Agency.

polyacrylamide

A high molecular weight synthetic polymer of carbon, hydrogen, oxygen and nitrogen, used to raise viscosity or reduce friction.

polyacrylamides

Synthetic polymers used to control filtration and to thicken injected water.

polyacrylate

A linear anionic polymer of acrylic acid, used in drilling fluids for filtration control and as a deflocculant.

polyalphaolefin

A synthetic base fluid made by polymerizing alpha olefins derived from ethylene, abbreviated PAO.

polyamines

Shale-inhibiting chemicals used in water-based drilling fluids.

polyanionic cellulose

A cellulose derivative used for filtration control and viscosity in water-base muds, abbreviated PAC.

polyanionic lignin

A modified lignin used for fluid-loss control in high-temperature water-base muds.

polycrystalline diamond bit

A polycrystalline diamond bit (PDC bit) is a special type of diamond drilling bit that does not use roller cones but instead has polycrystalline diamond inserts.

polycrystalline diamond compact (PDC)

A polycrystalline diamond compact (PDC) bit is a bit that uses synthetic diamond disks, called "cutters," to shear its way through rock with an ongoing scraping motion.

polycrystalline diamond compact (PDC) bit

A fixed-cutter bit whose synthetic diamond cutters shear the rock away in a continuous scraping action.

polyelectrolyte

A polymer that dissociates into charged units in water, so its chain carries many ionic sites.

polyelectrolytes

Charged polymers used to flocculate or disperse solids.

polyethylene

The most widely produced plastic, made from ethylene.

polyglycerol

A series of alcohols built from glycerol units, used as a shale inhibitor and lubricant in water-base mud.

polymer

A long-chain molecule made from identical or similar smaller molecules.

polymer flooding

A waterflood in which the injected water is thickened with polymer to improve how evenly it sweeps the reservoir.

polymer plug

A volume of polymer slurry set in the wellbore to gel into a viscous platform on which cement can be placed.

polymeric

Composed of long-chain molecules, as the polymers used in fluids and pipe.

polymerization

A reaction in which many similar molecules (such as olefins) are added together to form longer chain polymer molecules.

polyol

A low molecular weight water-soluble polymer or oligomer carrying many hydroxyl groups.

polyolefin

A synthetic hydrocarbon liquid made by polymerizing ethylene, used as the base fluid of a synthetic drilling mud.

polyphosphates

Phosphate polymers made by dehydrating orthophosphates with heat, used as thinners and as scale inhibitors.

polypropylene

A widely used plastic made from propylene.

polysaccharide

A carbohydrate built from many linked sugar units, forming the natural polymers used to viscosify fluids.

polysaccharides

Sugar-based polymers used to build viscosity and control filtration.

polystyrene

A polymer of styrene, and one of the largest petrochemical end products.

pontoons

The submerged buoyancy hulls of a semisubmersible.

pony rod

A short sucker rod run below the polished rod to bring the rod string to the exact length needed.

POOH

Pull out of hole — to trip the string out of the well.

pool fire

A fire burning above a spill of liquid hydrocarbon.

pooling

The combining of small separately owned tracts into a single unit large enough to satisfy well spacing rules.

pooling, pooled plots

In pooled plots, adjacent dips within a very small solid angle (2° to 3°) are presented as a single dip answer.

poor sorting

A wide range of grain sizes in one rock, which fills pore space and lowers permeability.

pop valve

A safety valve that "pops" open when the system pressure reaches the valve set point.

poppet

A valve element lifting straight off its seat, used where fast action matters more than throttling.

poppet value

A suction or discharge valve that uses round poppets which lift and seat by differential pressure to control gas flow. This valve is used for low pressure compression requirements.

poppet valve

A check valve whose disc lifts off a seat to allow flow one way and is pushed back onto it to block the other.

popping pressure

The pressure a relief valve opens at.

pore

An individual void space within a rock, capable of holding water, oil or gas.

pore fluid

The fluid occupying the pore space, whose pressure and compressibility change the rock's seismic response.

pore gas

Gas occupying the pore space of a rock rather than dissolved in its liquids.

pore geometry

The shape and connection of pores, which decides permeability at any given porosity.

pore pressure

The pressure of fluids within the pores of a reservoir (also called formation pressure), usually hydrostatic pressure or the pressure exerted by a column of water from the formation's depth to sea level.

pore size

The dimension of the pores, which sets capillary pressure and irreducible saturation.

pore space

The void within rock that holds fluids.

pore storage

The capacity of the pore system to hold and release fluid as pressure changes.

pore storage facility

A gas storage facility using the pore space of a depleted field or aquifer.

pore storage service

Gas storage sold in the pore space of a depleted field or aquifer.

pore system

The arrangement of pores and the throats connecting them, which decides permeability rather than porosity.

pore throat

Pore throat is the connection between the pores, often a fraction of the pore size.

pore volume

The total void space in a rock, the denominator for saturation and recovery calculations.

pore water

Water occupying pore space, whose salinity must be known before any resistivity log means anything.

pore-pressure gradient

The rate at which pore pressure increases with depth, in psi/ft or kPa/m.

pore-pressure transmission

A laboratory test measuring how effectively a drilling fluid stops pressure and filtrate moving through a shale sample.

poroelastic

Describing rock whose deformation and pore pressure are coupled.

porosimeter

A laboratory instrument that measures the pore or grain volume of a core plug, and so its porosity.

porosity

The measure of a rock's ability to hold a fluid. Porosity is normally expressed as a percentage of the total rock which is taken up by pore space.

porosity (phi)

The volumetric void space within rocks, being that space not occupied by solid material. Porosity is thus a measure of the reservoir's storage capacity.

porosity (phi), pores, pore spaces

Porosity, denoted by the Greek letter phi, is the volumetric void space within rocks, being that space not occupied by solid material. Porosity is thus a measure of the reservoir's storage capacity.

porosity (phi), pores, pore spaces, porous

The volumetric void space within rocks not occupied by solid material, denoted by the Greek letter phi. Porosity is a measure of a reservoir's storage capacity.

porosity crossplot

A chart combining two porosity logs to resolve lithology and true porosity.

porosity determination

Establishing porosity from log, core or test.

porosity exponent

The exponent m in Archie's relation between formation factor and porosity, typically about 2 in consolidated rock.

porosity log

A log measuring porosity, whether by density, neutron or sonic response.

porosity measurement

Determining pore volume, by log, core or a combination.

porosity system

The pore network and the way its elements connect.

porosity tool

A logging tool measuring porosity.

porosity unit

One percent of bulk volume as pore space, abbreviated p.u.

porous

Containing a network of small openings, or pores, capable of trapping substances in liquids and gases.

porous media

Rock or other solid with connected void space that fluid can move through.

porous medium

A solid containing interconnected void space through which fluid can move.

porous plate technique

A capillary pressure measurement in which one face of a core sits on a saturated porous plate while gas or oil pressure displaces water out through it.

porous rock

Rock with appreciable pore space.

port

An opening through which fluid enters, leaves, or passes in a valve body or compressor.

portable band saw

A portable, hand-held power saw with a blade that is a continuous loop, or band, of thin, flat metal. The band is run around a set of motor-driven pulleys that drive and support the band.

portable communicator

The handheld device configuring and interrogating a smart instrument.

portable compressor

A compressor mounted for transport to the work.

portable fire extinguisher

A hand-carried extinguisher for a fire still small enough to fight.

portfolio analysis

Judging investments as a set, on combined risk and return, rather than one at a time.

portfolio approach

Judging investments by their contribution to the whole rather than individually.

portfolio decarbonization

Reducing emissions by changing which assets a company holds, not only how it runs them.

portfolio optimization

Adjusting the mix of assets to improve the combination of return, risk and cash timing.

portfolio, programme and project

The set of investments, the group of related projects, and the single endeavor.

portland cement

Cement made by grinding clinker of hydraulic calcium silicates, which sets on contact with water alone.

portland cement clinker

The hard nodules of calcium silicates, aluminates and ferrites produced in the kiln, ground with gypsum to make cement.

position indicator

The device showing how far a valve or actuator has travelled.

positional bargaining

Haggling from stated demands, which hardens attitudes and obscures what each side actually needs.

positioner

The device ensuring a control valve actually reaches the position the signal asks for.

positioning system

The means of fixing survey and vessel location, whose accuracy limits everything mapped.

positive displacement

Moving a fixed volume per cycle regardless of pressure, unlike a centrifugal machine.

positive displacement compressor

A compressor trapping a fixed volume and reducing it, unlike a centrifugal machine.

positive displacement meter

A mechanical, fluid measuring device that measures by filling and emptying chambers of a specific volume.

positive displacement motor

A downhole mud motor whose helical rotor and stator turn the bit as fluid is forced through them.

positive displacement pump

A type of pump that uses a piston, diaphragm, gears, lobes, or other device in a reciprocating or rotary motion to push (positively displace) controlled amounts of fluid through the pump.

positive power

Power that is going to a load from a power source.

positive pressure check

A check for leakage from a respirator when a positive pressure is created inside the respirator by exhaling.

positive pressure respirator

A type of air-supplied respirator in which the tank continuously supplies air to the face mask at a pressure that is above atmospheric pressure.

positive pulse telemetry

Telemetry systems that create a momentary flow restriction in the drill pipe that produces a pressure pulse higher than the drilling mud volume pressure.

positive seating

The condition when a valve disc is firmly in place against its seat which prevents leakage.

positive suction head

Suction pressure above the liquid's vapor pressure, without which the pump cavitates.

positron

The positron, or anti-electron, is the anti-particle or the anti-matter counterpart of the electron.

possible reserves

Additional reserves that are less certain to be recovered than probable reserves.

post

To write measured values on a map or section at the locations they came from.

post-depositional

Occurring after deposition, such as cementation or faulting.

postmature

Said of kerogen heated beyond the oil window, past catagenesis and no longer able to generate oil.

postproduction

The fourth step in a production process, which includes handling, storage, packaging, and delivery to the customer.

posture

The position of the body. Generally speaking, good posture maintains the three natural curves of the spinal column. Good posture provides optimal back support and minimizes the risk of back injury.

potash

A potassium salt used in drilling fluids to inhibit clay swelling.

potassium

A chemical element with symbol K and atomic number 19. Orthoclase (potassium feldspar) is a common rock-forming mineral.

potassium hydroxide

A strong alkali used as the electrolyte in alkaline water electrolysis.

potassium ion

The K+ ion, added to water-base muds as potassium chloride to stabilize reactive shales.

potassium mud

A water-base mud carrying potassium ion, usually as potassium chloride, to inhibit reactive shale.

potential

Voltage.

potential difference

The difference in electrical potential between two points. In particular, the spontaneous potential recorded on well logs is the electrical potential between a surface electrode and one in the wellbore.

potential energy

Energy related to position or elevation.

potential field

A field satisfying Laplace's equation, so that it can be derived from a scalar potential — gravity and magnetics being the examples.

potential hazard

A hazard that exists but has not yet caused harm.

potential pollutant

A substance able to harm the environment if released.

potential reservoir

A formation that may hold producible hydrocarbons but has not been proven.

potential reservoir formation

A formation that may prove to hold producible hydrocarbons.

potential transformer

A transformer that reduces higher line voltage to a proportional lower voltage and supplies the lower voltage to protective relays or to instruments that monitor or measure the line voltage.

potentiometer

A variable resistor used to set or sense position.

potentiometric feedback amplifier

A variable gain inverting amplifier that used a potentiometer in its feedback path.

pounding

The action of the plunger on the downstroke hitting the liquid surface in a partially filled pump.

pounds per barrel

The US oilfield concentration unit for mud additives, one pound of material per 42-gallon barrel, written lbm/bbl.

pour point

The temperature at which a fuel can start being poured.

power

The rate at which work is done or energy is transferred. Electrical power is calculated by multiplying current times voltage, measured in watts. In mathematics, a number indicating how many times a base number is multiplied by itself.

power and influence

The sources of leverage a leader can draw on, only some of which come from position.

power and influence map

A chart of who holds sway over a decision and through whom they can be reached.

power cord

The flexible cable supplying a portable appliance.

power cylinder

The cylinder in which working pressure acts on a piston to do work.

power drill

A powered tool for boring holes.

power factor

The ratio of true (working) power to apparent power for an AC circuit, expressed as a percentage or decimal number.

power grinder

A powered abrasive tool for cutting or dressing metal.

power jigsaw

A portable, hand-held power saw that cuts with an up-and-down motion and is typically used to cut curves, circles, irregular shapes and patterns, and openings in boards or panels. Also called a saber saw.

power line carrier channel

A transfer trip communication channel in which transfer trip signals are sent over a transmission line.

power oil

Clean crude pressurized at surface and pumped down the well to drive a hydraulic downhole pump.

power piston

The piston that work is done on by process pressure.

power supply rejection ratio

The absolute value of the ratio of the change in supply voltages to the change in input offset voltage. Typically both supply voltages are varied symmetrically. Unless otherwise noted, both supply voltages are varied symmetrically.

power transformer

Generally, a transformer that supplies power to a circuit to do work. In transmission and distribution systems, typically a transformer that supplies large amounts of power, usually more than 500 KVA.

power transistor

A transistor designed to carry high current.

power-fluid injection rate

The rate at which power fluid is pumped down to drive a hydraulic downhole pump.

power-law fluid

A fluid whose shear stress varies as a power of shear rate, described by a consistency index and a flow behavior index.

pozzolan

A siliceous material with no cementing value of its own that reacts with lime and water to form a cement.

pozzolanic

Pertaining to a material that sets only in the presence of lime, having little cementitious value alone.

ppb

The drilling fluid abbreviation for pounds per barrel, a concentration of additive in mud.

ppg

Pounds per US gallon, the oilfield unit of fluid density.

ppm

Parts per million, a concentration of one unit of substance in a million units of the whole.

PPR

Pulses Per Revolution. An encoder specification indicating how many pulses the encoder produces for each revolution of the motor shaft.

practicable

Capable of being done in practice, a lower and more litigated standard than possible.

practice exam

A full-length rehearsal under exam conditions.

pre-employment test

A standardized assessment of ability, aptitude or personality used in selection.

pre-fractionator

A binary distillation tower that separates the lighter components of crude before the crude enters an atmospheric tower.

pre-qualification

Screening suppliers for capability, safety and financial standing before inviting bids.

pre-spud

"Pre-spud" refers to activities that take place before the drilling rig begins the actual drilling of the borehole. Such activities include site preparation, move-in and set-up of the rig and associated equipment.

pre-startup check

The verification made before starting, which catches what was left undone during maintenance.

precambrian

The vast interval before the Cambrian, largely lacking conventional petroleum systems.

precipitate

A solid substance that falls out of solution during a chemical reaction.

precipitation

A process by which a dissolved solid comes out of solution.

precipitator

A device used to separate particulates from exhaust gas leaving a boiler.

precision

How closely repeated measurements of the same thing agree with each other.

precision measurement

Measurement to a stated small tolerance.

predetermined value

A value set in advance that an action is triggered at.

predictive ai

Models that forecast outcomes or trends from historical and current data.

predictive analytics

Analysis estimating what is likely to happen next, from patterns in past data.

predictive analytics lifecycle

The sequence from framing the question through model building to acting on the output.

predictive modeling

Predictive modeling is the process of using known results to create, process, and validate a model that can be used to forecast future outcomes.

preemptive rights

A partner's right to match an outside offer and take the interest instead.

preferential right to operate

A reserved or acquired right to become operator of a lease, well, unit or concession ahead of other parties.

preferential right to purchase

The right of the other parties in a lease or unit to buy, in proportion to their interests, an interest a party proposes to sell.

preferred employer

A company people choose to join and stay with, which lowers both hiring cost and turnover.

prefilter

Filter removing bulk solids ahead of a finer element, extending the life of the one behind it.

preflush

The stage pumped ahead of the main treatment to condition the formation for it.

pregelatinized starch

Starch pre-cooked in water or steam so it disperses cold, without further heating.

preheater

An exchanger warming a stream before it reaches the main process, recovering heat that would be lost.

prehydrate

To mix a material with fresh water and let it swell fully before adding it to the mud system.

prehydrated

Mixed with water and allowed to swell before being added, so it performs as intended.

prehydrated bentonite

Bentonite mixed as a concentrated slurry in fresh water and allowed to yield before being added to the active system.

prehydration

The practice of hydrating a mud product in fresh water in a separate pit before it enters the active system.

prejudice

A held negative attitude toward a group, conscious rather than automatic.

premium motor spirit (PMS)

Gasoline, under the name used across West African markets.

premium thread

A proprietary connection with metal-to-metal sealing surfaces and a torque shoulder, rated well beyond API threads.

preparedness drill

A rehearsed emergency exercise, whose value lies in exposing what the plan gets wrong.

present value

What a future sum is worth today, once discounted.

presentation design

Structuring and visualizing material so it supports the spoken argument.

preservation

The stage of a petroleum system after accumulation, during which the charge either survives or is degraded.

preservative

A biocide added to a water-base mud to stop bacteria degrading its organic polymers.

preserved core

Core sealed at the wellsite to keep its fluids and wettability as they were when it came out of the hole.

preset

A memory word in which a timer or a counter stores the maximum time or count.

preset value

A value set in advance.

pressure

The amount of force applied per unit of area, often expressed in pounds per square inch (psi).

pressure build up test

A pressure build up test is used for determining the effective drainage radius of a wellbore in addition to the presence of permeability barriers or other production deterrents; the well is shut for a specified period, and a bottom hole pressure bomb is run to record the reservoir pressure.

pressure buildup

The rise in bottomhole pressure recorded after a flowing well is shut in.

pressure buildup analysis

The interpretation of shut-in pressure against time to derive permeability, skin and reservoir boundaries.

pressure capability

The pressure a lift system can generate or withstand, and so the depth from which it can lift.

pressure control valve

A valve modulating flow to hold pressure.

pressure controller

The instrument holding pressure, by throttling either the inlet or the outlet but not both.

pressure curve

The recorded trace of pressure against time or depth.

pressure cutout switch

A switch that turns a reciprocating compressor on or off in response to changes in pressure.

pressure cutout switches

Switches that turn a reciprocating compressor on and off in response to changes in pressure.

pressure depletion

The fall in average reservoir pressure as fluids are produced and not replaced.

pressure differential

The pressure drop between two points, which is what actually drives flow or reveals fouling.

pressure differential indicator

An indicator that displays the difference in pressures measured at two different points.

pressure differential transmitter

A transmitter produces a signal that is proportional to the difference in pressure between the two points in a system.

pressure drawdown

The difference between reservoir pressure and flowing bottomhole pressure, the force that drives fluid into the well.

pressure drilling mpd

Managed pressure drilling, controlling annular pressure precisely to stay within a narrow window.

pressure drop

A loss of pressure that results when a fluid passes through a constriction or smaller area such as an orifice plate.

pressure falloff

The decline in pressure recorded after injection into a well is stopped.

pressure filter dryer

A type of dryer that uses pressure and a hot gas, usually nitrogen, to force moisture out of wet cake that is on a mesh screen inside the drying vessel.

pressure fluctuation

Pressure varying rather than holding, which upsets measurement and fatigues equipment.

pressure gauge

A pressure device used to measure pressure. Many different types of pressure gauges have been developed for use in well testing over the years. These include helical bourdon tube gauges, strain gauges, quartz crystal gauges and surface readout gauges.

pressure gradient

The rate at which pressure changes with depth, quoted in psi/ft or kPa/m.

pressure hunt

Watching drilling parameters — d-exponent, cuttings, gas, torque, temperature — for the signs that formation pore pressure is changing.

pressure indicator

A local gauge showing pressure, read during rounds rather than logged by the control system.

pressure integrity test

A test that pressures up the open formation below a casing shoe to establish the strength it will hold.

pressure measurement

Determining pressure, and the most common measurement in a process plant.

pressure override

The difference between the full flow pressure and the cracking pressure of a spring-biased valve.

pressure packing

Rings within a cage that surround the piston rod to form a seal which prevents pressurized gas from escaping into the atmosphere or the crankcase.

pressure psig

Pressure measured relative to atmospheric, the convention for surface equipment ratings.

pressure reducing valve

A pressure control valve designed to lower the pressure in one part of a hydraulic or other system.

pressure regulator

A valve holding downstream pressure constant regardless of upstream variation.

pressure relief valve

A general term used for relief valves, safety valves, and safety relief valves.

pressure safety valve

The relief device that opens automatically to prevent a vessel exceeding its design pressure.

pressure sender

The transducer in a pressure measurement system, which converts pressure into the signal a gauge or control system reads.

pressure sensor

The element converting pressure into a signal.

pressure setpoint

The pressure a controller holds, and the number changed when operating conditions shift.

pressure storage tank

A tank built to hold volatile liquids under pressure, so they stay liquid rather than flashing to vapor.

pressure switch

A pilot device set to actuate at a specific set point based on process pressure, often installed to initiate alarms or start standby equipment if abnormal pressure conditions develop.

pressure tank

A tank designed to store liquids at pressures above 0.5 psig (higher than atmospheric pressure).

pressure tank cars

Tank cars that have working pressures greater than 100 psi.

pressure taps

Threaded holes located on a meter tube or orifice fitting where upstream and downstream static pressures are taken.

pressure transient

The pressure change over time after a rate change, analyzed to infer reservoir properties.

pressure transient analysis

Pressure transient analysis is the analysis of pressure changes over time.

pressure transient test

A test in which rate is changed and the resulting pressure response is matched to a model of the reservoir.

pressure transient well test

A test in which rate is changed and the resulting pressure response is interpreted against a reservoir model.

pressure transient well tests

In pressure transient well tests, the pressure is recorded as a function of time and interpreted using various analysis methods. These include build-up tests and drawdown tests in production wells and falloff tests in injection wells. Pressure transient well test analysis procedures are based on classical mathematical relationships between flow rate, pressure and time.

pressure transmitter

A device that converts a pressure measurement to a signal and sends that signal to another device, such as a recorder that is located some distance away.

pressure vent

A vent that is used to release excess pressure from a tank.

pressure vents

Vents that are used to release any excess pressure that builds up in a tank.

pressure-compensated flow control valve

A flow control valve that has a structure built in to sense upstream pressure and adjust to it to maintain a constant pressure drop.

pressure-composition diagram

A plot of saturation pressure against injection gas concentration at fixed temperature, showing how phase behavior changes as gas is added.

pressure-drawdown analysis

Interpretation of the pressure decline recorded while a well is flowing at constant rate.

pressure-squared plot

A gas well analysis plot using pressure squared against a time function, valid at low pressure.

pressure/vacuum (P/V) valve

A valve designed to provide normal venting to a storage tank; also called a breather valve or a conservation vent.

pressurized mud balance

A mud balance whose cup can be pressurized, so entrained air is compressed out of the measurement.

pressurized tank

See High pressure tank.

pressurizing

Raising pressure in a system.

prestack

Seismic data before the traces are summed, retaining the offset information.

pretreating

The process and activities associated with the removal of contaminates (especially sulfur).

pretreatment

Conditioning a feedstock before the main process, usually to protect a catalyst downstream.

preventer

The stack of valves closing on the wellbore to contain pressure when the well flows unexpectedly.

preventive action

Action taken to stop a fault occurring rather than to correct one.

preventive maintenance

Systematic monitoring and testing of equipment to detect conditions that could lead to failure, and performance of routine maintenance in order to delay failure.

price differential

The difference in price between two grades or locations.

price exposure

The amount by which a position's value moves when the reference price moves.

price reporting agency

A publisher whose daily assessments serve as the reference price in physical contracts.

price volatility

The degree to which price fluctuates, which determines the value of hedging.

pricing period

The days whose published quotations are averaged to set a cargo's price.

pricing strategy

The deliberate approach to setting price, reflecting value, cost and competition.

pricing-in and pricing-out

The separate periods over which a purchase and a sale fix their prices.

primary and secondary message

The one thing the audience must take away, and the supporting points.

primary and secondary roles

The main function a person holds and the supporting ones they also carry.

primary burn

See Catalyst burn.

primary cementing

The placing of cement in the annulus behind a casing or liner as it is first run.

primary coil

The coil in a transformer to which power is applied.

primary completion components

The principal elements of a completion — tubing, packer, nipples, safety valve — that make the design work as intended.

primary element

Part of a meter station, consisting of the meter tube, orifice fitting (or flange unions), and orifice plate (or metering device).

primary loop

The outer, or master, control loop in a cascade control system that provides the set point for the secondary, inner, or slave loop.

primary migration

The expulsion of newly generated oil and gas out of the fine-grained source rock that made it.

primary porosity

Pore space that has been present since the sediment was deposited, surviving compaction and lithification.

primary production

The first stage of production, driven only by the reservoir's own energy — solution gas, water drive or gravity drainage.

primary recovery

The fraction of the hydrocarbon in place produced under natural reservoir energy alone.

primary recovery method

Production driven by the reservoir's own energy, with nothing injected to support it.

primary reflection

Seismic energy that has reflected once on its way from source to receiver.

primary term

The fixed period for which a lease runs without production, after which it expires unless drilling or production has begun.

primary vessel

A vessel that is a major, or central, part of a process system.

primary winding

The coil or winding in a transformer that receives the incoming power (to which voltage is applied).

prime mover

A piece of equipment (such as a turbine, motor, or engine) that provides the mechanical energy necessary for operating an AC generator, beam pumping unit, or other equipment.

primer

A solvent that breaks down the surface of plastic pipe and fittings so that cement will more completely join the two, making a good seal for pipe joints.

primer cord

A flexible cord of high explosive that carries detonation from the detonator along the gun to each charge.

priming

Filling a pump with liquid so it can develop suction.

principal axis

The direction along which the variance of a set of data is greatest, with the remaining axes orthogonal to it.

principal component analysis

A method that re-expresses correlated data on new orthogonal axes ordered by how much variance each explains, abbreviated PCA.

principal-agent relationship

The arrangement where one party acts for another, whose interests may not align.

principled negotiation

Negotiating on the merits of the problem rather than by trading positions.

principles of change

The general rules that hold across changes, whatever the specific initiative.

printout

A printed record of data.

prior learning

See, Accreditation of Prior Achievement (APA).

prioritization

Deciding what will not be done, which is the part people skip.

private cloud

Cloud infrastructure dedicated to a single organization, giving cloud automation while keeping control of the hardware and the data.

private offering

A program run for a single client, tailored to its assets and people.

pro

A prefix for the name of a hydrocarbon that has three carbon atoms.

pro forma financial statements

Projected accounts built from a project's forecast cash flows.

pro forma invoice

A preliminary invoice issued so a client can raise payment before the service is delivered.

probabilistic

Probabilistic is being based on, or adapted to, a theory of probability; subject to, or involving, chance variation.

probability

A number between zero and one giving how likely an outcome is across the possible outcomes of a trial.

probability distribution

The range of possible values for an uncertain input, with the likelihood of each.

probable and possible reserves

The less certain increments beyond proven, carrying progressively lower confidence.

probable reserve

Reserves less certain than proved but more likely than not to be recovered.

probable reserves

Additional reserves that are less certain to be recovered than proved reserves but which, together with proved reserves, are as likely as not to be recovered.

probe

A device inserted into a meter tube for taking samples, which may be elbow-shaped, beveled, or a straight tube made of stainless steel. Also, a short, pointed metal tool for testing the hardness of drill cuttings.

problem crude oils

Crudes carrying contaminants or instabilities that foul equipment or upset a refinery's yield.

process control

Keeping a process operating within its intended limits.

process control system

A group of instruments used to automatically control the values of process variables.

process delay

The time between when a control action takes place and when the process has substantially destabilized in response to that action; includes lag and dead time.

process disturbance

Any unwanted change in a system that tends to adversely affect the value of a controlled variable.

process gain

The proportionality between the control output and the process variable through the process (rather than through the controller); the relationship between a change in controller output and the resulting change in a process variable.

process gas

Gas present during or produced by a process or piece of equipment.

process improvement

Deliberate change to a process to raise quality, speed or cost performance.

process instrumentation

Instruments that monitor and/or control process variables.

process load

The demand for the output of, and the input to, a process. Any change in load reflects back on control loops as a process upset.

process of elimination

A troubleshooting method in which circuit components or parts of a process that are working properly are eliminated from consideration until only the source of the problem remains.

process reaction

A chemical change in which the atoms or ions of one or more substances are rearranged to form one or more new substances.

Process Safety Management (PSM)

The systematic control of hazards capable of causing a major release, fire or explosion.

process variable

A physical condition of process materials (such as temperature, level, flow rate, pressure, pH, or turbidity) that changes and is measured, manipulated, or controlled by a control loop.

processed gas

Gas that has been through treatment and meets specification.

processing

The second step in a production process, in which the necessary physical or chemical changes are made to feedstocks in order to produce the final product.

processing deal

An arrangement where one party's crude is run through another's refinery for a fee.

processor status

The stored word reporting a programmable controller's health and mode.

procrastination

Deferring important work in favor of easier or more urgent-seeming tasks.

procurement

The process of acquiring goods and services from outside the organization.

procurement health check

A diagnostic review of how well the contracting function is actually working.

prodelta

A prodelta is the outermost, subaqueous portion of a delta, characterized by the deposition of fine-grained sediments, primarily silt and clay, that are carried by a river and settle at the base of the delta front. It is the most distal part of the delta, furthest from the river mouth, and is often affected by the influence of waves and tides.

prodelta shale

The fine sediment deposited seaward of a delta front, often a seal or source.

produced fluid

Any fluid that comes out of the well from the formation, as opposed to one that was pumped in.

produced water

Water produced in connection with, or generated during, oil and natural gas exploration, development, and recovery operations.

producible

Capable of flowing to surface at rates worth having.

producing asset

A field already on stream and generating revenue.

producing formation

The rock interval from which a well takes its oil, gas or water.

producing reservoir

A reservoir currently on production.

producing well

A well currently delivering fluids to surface.

product

The answer to, or result of, a multiplication problem.

product cooler

Exchanger bringing a finished product to storage temperature.

product development life cycle

The stages from concept through development and launch to retirement.

product gasoline

Finished gasoline meeting sales specification.

product liability

Responsibility for harm caused by a defective product.

product life cycle planning

Planning across a product's whole life rather than only its development.

product outlet

The connection finished product leaves by.

product owner

The person accountable for what the team builds and in what order.

product pipeline

A pipeline carrying refined products rather than crude.

product quality report

A document that notifies the customer that the finished product meets the agreed-upon specifications; also called a product brief or a certificate of analysis.

product quality specification

The set of measured limits a product must meet before it can be sold.

product safety

The obligation to ensure a product does not injure those who use it as intended.

product separator

The separator making the final split before product goes to storage.

product specification

The measured limits a product must meet before it can be sold.

product tanker

A ship built to carry refined products, with coated tanks to keep them clean.

product vapor

Vapor drawn as product rather than returned as reflux.

product warranty

A promise about a product's condition or performance, express or implied by law.

production

The phase of a field's life, after exploration and development, in which hydrocarbons are drained from it.

production bonus

A lump sum payable to the host government when production first reaches an agreed level.

production casing

The casing string set across the reservoir, inside which the completion is installed.

production log

Production logs are run in completed wells to determine the nature and behavior of fluids in, and around, the borehole during production or water injection.

production log, production logging

A production log is a record of one or more in-situ measurements that describe the nature and behavior of fluids in or around the borehole during production or injection. Production logs are run for the purpose of analyzing dynamic well performance and the productivity or injectivity of different zones, diagnosing problem wells, or monitoring the results of a stimulation or completion.

production logging tool

A tool run in a producing well to find where the flow and the water are entering.

production packer

The seal set between tubing and casing that isolates the annulus and anchors the bottom of the tubing string.

production payment

A right to a share of production or its proceeds that ends once a specified sum or volume has been delivered.

production penalty

A payment owed to the host government when contracted production levels are not achieved.

production period

The flow period that precedes a shut-in, whose rate and duration determine the buildup that follows.

production phase

The phase of petroleum operations in which oil and gas is produced, processed and sold to the regional market.

production plan

The aggregate plan of output over a horizon, from which the master schedule derives.

production profile

A production profile is the quantity of hydrocarbon produced over successive periods of time.

production separator

The separator taking well fluid and making the first split of gas, oil and water.

production service contract

A contract under which a company provides services to a host state and is paid a fee rather than taking a share of production.

Production Sharing Agreement (PSA)

The same instrument as a production sharing contract, under the name used in some jurisdictions.

production sharing contract (PSC)

An agreement between a host government and the owners (or co-owners) of a well or field regarding the percentage of production each party will receive after the parties have recovered a specified amount of capital and operational expenses.

production string

The tubing through which reservoir fluids are brought to surface.

production tree

The valve assembly installed on the wellhead for the producing life of the well, after any frac tree has been removed.

production tubing

The tubing string used to transport the well fluids to the surface.

production tubing, tubing

Production tubing is a wellbore tubular used to produce reservoir fluids. Production tubing is assembled with other completion components to make up the production string.

production wing

The side outlet of a Christmas tree through which produced fluids leave the well.

productive interval

The depth range actually contributing flow.

productive well

A well that is capable of producing hydrocarbons in sufficient quantities to justify commercial exploitation.

productivity

Output relative to the resources consumed producing it.

productivity index

A mathematical measure of a well's potential or ability to produce, expressing the ability of a reservoir to deliver fluids to the wellbore. Usually stated as volume delivered per psi of drawdown at the sandface (bbl/d/psi). The symbol J is commonly used, preferred by the Society of Petroleum Engineers.

productivity index (\( \small J \))

The productivity index represents the dynamic response of the reservoir and its fluid properties within the drainage area of a specific well. Each well has its own productivity index value, and each value applies to a specific average reservoir pressure.

productivity test

A test measuring what a well will produce at stated flowing and reservoir pressures.

professional networking

Building relationships that carry information and opportunity.

PROFIBUS

An open network protocol for connecting groups of input and/or output devices to a PLC system.

PROFIBUS protocol

A standard communications protocol that governs the transmission of data through networks.

proficiency statements

profile

To measure how a property varies along a line across the survey area.

profile modification

Treating a well or reservoir to change where fluid enters or leaves it, so as to reduce unwanted water production.

profile testing

Sampling a flowing stream at several points across the pipe to establish how far the phases have stratified.

profiling

The practice of measuring a property's lateral variation along a traverse.

profit oil

The share of production remaining after the Cost Oil and, if applicable, Royalty and First Tranche oil, have been paid. The Profit Oil is shared between the Government and the Operator on a fixed (65:35 %) or sliding scale.

profitability cycle

The recurring swing in industry margins between shortage and oversupply.

profitability index

Value created per unit of capital invested, used to rank projects when capital is short.

progradation

The seaward growth of a beach, delta, or fan by the progressive deposition of sediments by rivers or shoreline processes.

progradational

Building outward into the basin, so successive beds step seaward.

prograding

Building seaward, the stacking pattern produced when sediment supply outpaces sea level rise.

prograding delta

A prograding delta is a coastline that is advancing toward the sea as a result of the accumulation of waterborne sediment.

program files

One of two main types of PLC files, in which one or more ladder program files are stored.

programmable

A characteristic of computers that allows them to perform widely varied tasks, depending on the instructions they receive through input commands or software programs.

programmable logic controller

An industrial controller executing stored logic, which replaced relay panels.

progressive cavity

A pump moving fluid in sealed cavities formed between a helical rotor and stator.

progressive cavity pump

A pump moving fluid in sealed cavities between a helical rotor and an elastomer stator, tolerant of solids and viscous oil.

progressive cavity pumping system

An artificial lift system in which a helical rotor turning inside an elastomer stator moves fluid up in sealed cavities, abbreviated PCP.

progressive discipline

Escalating steps from informal warning to dismissal, each giving a chance to correct.

progressive gels

Gel strengths that keep building with time, so the ten-minute reading is far above the ten-second one.

prohibited condition

Any condition in a permit space that is not allowed by the permit during the period when entry is authorized.

project

The entire contents of the memory of a PLC.

project artifact

Any document or output the methodology requires the project to produce.

project charter

The document authorizing the project and naming its objectives, sponsor and manager.

project communications plan

Who needs what information, how often and in what form.

project execution plan

The document setting out how the project will be delivered: organization, contracts, schedule, controls.

project financing

Funding a project on the strength of its own cash flow rather than the sponsor's balance sheet.

project governance and voting

The committee structure and voting thresholds by which venture decisions are taken.

project life cycle

The phases every project passes through from initiation to closure.

project methodology

The defined approach and its associated processes and documents.

project participants

Entities or individuals that agree to invest in and manage an oil and gas project. These may be private enterprises (including companies, individuals, and non-governmental organizations) or public entities.

project plan

The integrated statement of how the project will be executed and controlled.

project procurement

Buying goods and services the project requires from outside.

projection

Projection has to do with the angle at which the image was produced from the Satellite to the point on the Earth.

promoted interest

Increased working interest gained by the assignor as a result of a farmout agreement. Traditionally, a farmout might stipulate that a latecomer who farms in must pay “1/3 for 1/4 working interest”, meaning they pay 33 1/3% of the costs but only earn a 25% working interest. The additional 8 1/3% represents a promoted interest for the original participant.

promotional mix

The combination of advertising, selling, public relations and sales promotion used.

promotor

A substance that is added to a regenerator to promote the combustion of carbon monoxide to carbon dioxide in the dense phase of the regenerator.

prompt

The instruction or question given to a generative model to elicit its output.

prompt cargo

A cargo loading immediately or in the nearest window, priced off the front of the curve.

prompt engineering

Composing and refining the input given to a language model to improve the quality of what it returns.

prompt gamma rays

Prompt gamma rays are gamma rays emitted very quickly after the nucleus becomes excited.

proof burn

A stage of catalyst regeneration in which additional air is supplied to reactors in order to help ensure that all of the carbon deposits are burned off of the catalyst.

proof mass

A proof mass, or test mass, is a known quantity of mass used in a measuring instrument as a reference for the measurement of an unknown quantity.

proofreading

The final check for errors in a document already edited and laid out.

propagation constant

The complex quantity describing how a wave's amplitude and phase change per unit distance as it travels.

propagation resistivity

A resistivity log recorded while drilling from the phase shift and attenuation of an electromagnetic wave between receivers.

propagation resistivity measurement

An electromagnetic resistivity measurement made from the drillpipe, typically at 2 MHz, from phase and amplitude between receivers.

propagation time

The time an electromagnetic wave takes to cross a fixed spacing in the formation, the measurement behind the dielectric log.

propane

A three-carbon alkane (C3H8) of the paraffin series that is a gas at standard temperature and pressure but easily liquefied under pressure. Used as an LPG fuel, sent to refineries, or used as a petrochemical feedstock.

propane butane

The mixed liquefied petroleum gas stream.

propane gas

Propane in vapor phase, both a product and the working refrigerant in many plants.

propane refrigerant

Propane used as the working fluid in refrigeration, cheap and available on site but flammable.

propane vapour

Propane boiled off from liquid, the stream a refrigerant compressor takes.

propeller fan

A type of axial fan that consists of blades mounted on a hub; a shaft; and a drive motor. The blades are angled to lift, or catch, the air and move it along the shaft to the discharge side of the fan.

proper respirator fit

A tight, leak-free seal between the wearer's face and a respirator mask or facepiece.

property insurance

Insurance policy carried by the oil or gas company that protects the owner of a property from loss or damage resulting from the company's operations.

property law

The rules governing ownership and interests in land, minerals and other property.

proportional band

The error range over which a controller produces a control output proportional to the error. Narrow proportional band is equivalent to high controller gain. The inverse of controller gain, equal to change in input divided by change in output times 100%.

proportional control

A process control algorithm in which the output action is directly proportional to the difference between the input variable and its set point.

proportional solenoid

A solenoid that reacts proportionally to the electrical signal. As the electrical signal is increased, the energy in the solenoid increases at the same rate.

proportionality

A fixed ratio between two quantities.

proppant

A solid material (typically sand, treated sand, or man-made ceramic materials) designed to keep induced hydraulic fractures open during or following fracturing treatment so that oil and natural gas can flow through the fractures to the wellbore.

proppant concentration

The proppant carried per unit of fluid, which sets the fracture width achieved.

proppant pack

The bed of proppant left in the fracture, whose conductivity determines the treatment's value.

proprietary system

A system that uses a standard defined by a specific vendor for connection of only that vendor's equipment. An example is Allen-Bradley's Data Highway Plus.

propylene

A type of olefin commonly used in alkylation reactions; consists of three carbon atoms and six hydrogen atoms.

propylene glycol normal propyl ether

A solvent used with water to break an oil- or synthetic-base mud emulsion so the sample can be titrated.

prorated well

A well whose maximum production rate is capped by a regulatory authority rather than by its own capability.

proration unit

The acreage a regulator judges one well can efficiently drain at a given depth, and against which its allowable is set.

prospect

A prospect is an area of exploration in which hydrocarbons have been predicted to exist in economic quantity. A prospect is commonly an anomaly, such as a geologic structure or a seismic amplitude anomaly that is recommended by explorationists for drilling a well.

prospect area

The mapped area of a potential accumulation.

prospecting

Searching for hydrocarbon accumulations before any well is drilled.

prospective resource

Undiscovered quantities estimated to be potentially recoverable from an untested prospect.

prospective resources

Prospective resources are the quantities of petroleum estimated, at a given date, to be potentially recoverable from yet to be discovered (undrilled exploration prospects) accumulations. Prospective Resources have both an associated chance of discovery and a chance of development in the event of the exploration success case.

protective clothing

Clothing worn to prevent injury.

protective device

A device acting to remove a hazard automatically, such as a fuse or relief valve.

protective equipment

Equipment worn or fitted to keep a hazard from reaching the person.

protective gear

Equipment worn to keep a hazard from the wearer.

protective laboratory practices and equipment

Those laboratory procedures, practices, and equipment accepted by laboratory health and safety experts as effective, or that the employer can show to be effective, in minimizing the potential for employee exposure to hazardous chemicals.

protective measure

An action or device reducing a risk.

protective relay

A relay designed to quickly detect and isolate a fault.

protective suit

Protective clothing made of materials that resist damage and prevent chemicals from soaking or burning through to the wearer's skin.

protocol

The rules applying to both network hardware and network data transmission procedures; devices connected on a common network need to operate according to the same protocol.

protofuel

A gasoline blend that has been tested in several labs against reference fuels to determine its octane number.

proton

A stable subatomic particle with a positive electric charge equal in magnitude to the negative charge of an electron, with a mass slightly less than that of a neutron. Protons occur in all atomic nuclei.

proton resonance frequency

Proton resonance frequency is a phenomenon in which protons absorb energy from an alternating magnetic field at certain characteristic frequencies when they are also subjected to a static magnetic field.

protons

The proton is a subatomic particle with an electric charge of +1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons.

proved developed reserves

Proved reserves that can be expected to be recovered through existing wells with existing equipment and operating methods or in which the cost of the required equipment is relatively minor compared to the cost of a new well.

proved reserves

Proved oil and gas reserves are those quantities of oil and gas which, by analysis of geoscience and engineering data, can be estimated with reasonable certainty to be economically producible - as defined by the U.S. Securities and Exchange Commission regulations and a typical company's Policy for Reserves Estimation, Accounting and Reporting.

proven reserves

Quantities recoverable with reasonable certainty under current conditions and prices.

prover

The calibration device against which a flow meter is checked.

prover connection

The pipework tying a meter to its prover.

prover loop

The closed calibrated circuit a displacer travels to prove a meter.

prover loop connection

The pipework tying a meter into the prover circuit.

prover loop connections

The connections and valves on the LACT unit which provide easy connection of a volume prover for accuracy checking of the LACT meter.

prover pipe

The calibrated pipe section of a pipe prover.

prover volume

The certified volume of the prover, the reference every meter factor is calculated against.

proving rate

The flow a meter is proved at, which must match its operating rate for the factor to apply.

proving report

The record of a meter proving, carrying the meter factor it established.

proving run

One pass of the displacer through the prover, several of which make a proving.

proximity log

A pad-contact resistivity device focused to read a short distance past the mudcake into the flushed zone.

proximity switch

An electronically activated switch that has the same function as a limit switch, but requires no physical contact with its actuator. Also called a "prox" switch.

proximity work

Work that is performed near a hazard, but not actually in contact with hazard.

pseudocritical

The composition-weighted critical properties of a mixture, used to predict gas behavior.

pseudogeometrical factor

A curve describing how much of a logging measurement comes from each radial distance out from the tool.

pseudoplastic

Said of a fluid whose viscosity falls as shear rate rises, with no gel structure that rebuilds at rest.

pseudopressure

A transformed pressure variable that linearizes gas flow equations.

pseudopressure plot

A gas well analysis plot using real gas pseudopressure against a time function, valid at any pressure.

pseudostatic spontaneous potential (PSP)

Pseudostatic spontaneous potential is the ideal spontaneous potential (SP) that would be observed opposite a shaly, permeable bed if the SP currents were prevented from flowing. In other conditions, however, the SP reads close to the pseudostatic spontaneous potential (PSP). Spontaneous potential (SP) refers to the natural electrical potential difference that arises in geologic al formations, primarily due to the movement of ions and differences in salinity between fluids.

pseudostatic spontaneous potential, PSP

The pseudostatic spontaneous potential (PSP) is the ideal spontaneous potential that would be observed opposite a shaly, permeable bed if the SP currents were prevented from flowing. In the middle of a thick, permeable bed whose resistivity is not too high, the SP reads close to the pseudostatic spontaneous potential (PSP).

pseudosteady state

Pseudosteady State is the period in which hydrocarbons in a reservoir flow in a steady state into the well. It can also be referred to as the “stabilized” flow condition from a bounded drainage area. In a pseudosteady flow, the pressure at various locations in the reservoir linearly declines as a function of time and remains constant at every point.

PSF

Pounds per square foot, a measurement of pressure.

PSI

Pounds per square inch, a measurement of pressure.

psia

Pounds per square inch absolute. Equal to the gauge pressure plus the atmospheric pressure. Absolute pressure is pressure relative to zero or an absolute vacuum.

psig

Pounds per square inch gauge. The pressure in a vessel or container as shown on the pressure gauge.

PSP

Pseudostatic spontaneous potential: the SP deflection actually recorded opposite a shaly sand, reduced below the static value by the shale present.

PSV

Pressure Safety Valve.

psychological safety

Confidence that speaking up will not be punished, which predicts team performance more than talent does.

public accountability

The obligation to explain and justify conduct to those affected by it.

public cloud

Shared, on-demand computing capacity bought from a provider such as AWS, Microsoft Azure or Google Cloud.

public key infrastructure (PKI)

The system of certificates and authorities that binds public keys to identities.

public offering

A scheduled program open to participants from any company.

public speaking

Addressing an audience live, where delivery affects reception as much as content.

publishing standards

The house rules a document must meet before it may be issued.

puking

A condition in which excessive vapor pressure forces liquid up to the next tray level, and possibly out of the top of the column.

pull out of the hole

To trip the string out of the well, abbreviated POOH.

pull-apart basin

A basin opened at a bend or offset in a strike-slip fault system.

pull-up

An apparent structural high on a seismic section caused by a high-velocity body above it, not by real relief.

puller

A tool applying axial force to draw a component off a shaft.

pulley

A wheel carrying a belt to transmit rotation or change speed.

pulling a vacuum

A condition in which the pressure inside a tank becomes much lower than the pressure outside the tank; as a result, the tank may be crushed by the outside air pressure.

pulling tool

A slickline or coiled tubing tool that latches a downhole device and retrieves it to surface.

pulling vacuum

Reducing pressure below atmospheric with ejectors or pumps.

pulsation

Periodic increases or decreases in pressure.

pulsation dampener

Vessel absorbing the pressure pulses a reciprocating machine makes, protecting piping from fatigue.

pulse counter

A device used in meter proving which counts the pulses generated by the meter.

pulse echo

A measurement in which an ultrasonic transducer fires a pulse at the casing and interprets the returning echo train.

pulse echo mode

Pulse echo mode is a technique in which an ultrasonic transducer, in transmit mode, emits a high-frequency acoustic pulse towards the borehole wall, where it is reflected back to the same transducer operating in receive mode.

pulse shape

The form of the source wavelet, which sets resolution and how reflections appear.

pulse signal

Signal such as steps and pubes that only occur once are called single-shot or transient signals. The pulse indicates what you would see if you turned a power switch on and then off again. A collection of pulses traveling together creates a pulse train.

pulse telemetry

Sending data to surface as pressure pulses in the mud.

pulse width modulation

A method of producing the voltage required to drive a motor in a variable speed application.

pulse-echo mode

Pulse-echo mode is a technique in which an ultrasonic transducer, in transmit mode, emits a high-frequency acoustic pulse towards the borehole wall, where it is reflected back to the same transducer operating in receive mode.

pulsed neutron

A logging tool emitting neutron bursts to measure saturation through casing.

pulsed neutron capture

A log firing neutron bursts and timing their capture, used to see fluids through casing.

pulsed neutron capture logging tools

Pulsed Neutron Capture (PNC) logging tools are electronic logging devices that repeatedly generate very short bursts of high energy neutrons at an energy level of 14 MeV. Neutron capture is a type of nuclear reaction in which a target nucleus absorbs a neutron (uncharged particle), then emits a discrete quantity of electromagnetic energy (gamma-ray photon).

pulsed neutron log

A pulsed neutron log uses induced gamma ray spectroscopy with a pulsed neutron generator. The elemental yields are derived from two intermediate results: the inelastic and the capture spectrum. The pulsed neutron log can indicate the oil saturation, but is affected by the formation water salinity, and the reservoir's lithology, porosity and clay content. The depth of investigation of the log is several inches into the formation. It can be run in open or cased hole.

pulsed neutron spectroscopy log

A wireline log of the yields of different elements in a formation, measured using induced gamma ray spectroscopy with a pulsed neutron generator. Elemental yields are derived from two intermediate results: the inelastic spectrum (basis for the carbon-oxygen log) and the capture spectrum (dependent on hydrogen, silicon, calcium, iron, sulfur, and chlorine).

pulsed neutron spectroscopy measurement

A cased-hole measurement of the gamma ray energy spectrum produced when a pulsed neutron generator bombards the formation.

pulsed-neutron holdup log

A log of gas, oil and water holdup in the wellbore derived from pulsed neutron spectroscopy rather than from probes.

pulser knob

A knob on some smart controllers that, when turned by a user, can reset a variable such as a setpoint, ratio, or bias.

pulverizer

The mill grinding coal fine enough to burn in suspension.

pump barrel

The cylinder of a downhole sucker rod pump, inside which the plunger travels.

pump casing

The pressure-containing shell of a pump.

pump cavitation

The formation and violent collapse of vapor bubbles in a pump starved of liquid at its suction.

pump characteristic curve

A graph curve that shows the relationship of two or more variables of pump operation, such as pressure and flow.

pump discharge

The outlet side of a pump.

pump inlet

The suction connection of a pump.

pump intake

Where fluid enters the downhole pump, whose pressure decides whether the pump fills.

pump manifold

The valves, lines and gauges through which power fluid or produced fluid is routed at a pumping installation.

pump pit

A below-grade location for a pump in a tank farm.

pump shaft

The rotating shaft carrying a pump's impeller.

pump slab

An above ground location for a pump in a tank farm.

pump submergence

The height of fluid standing above the pump intake while the well is producing.

pump suction

The inlet side of a pump.

pump volumetric efficiency

Actual output divided by the theoretical displacement of the pump, expressed as a fraction.

pump-arounds

Liquid streams from a distillation tower that are cooled in heat exchanger trains and then returned to the tower.

pumpability

How long a slurry stays fluid enough to be pumped, measured by the API thickening time test.

pumpable

Fluid enough to be pumped, and the period for which a cement remains so.

pumped off

The level of fluid in the well is lower than the position of the pump.

pumper

A mobile high-pressure pump unit brought to the wellsite for cementing or stimulation.

pumping schedule

The stage-by-stage plan of what fluid is pumped, in what volume and at what rate, during a treatment.

pumping system

The complete artificial lift installation, surface and downhole.

pumping tee

Surface connections to allow flow lines to be connected to the well head.

pumping time

The time needed to mix and place a cement slurry, plus a safety margin over it.

pumping unit

The surface beam-and-crank machine that reciprocates a rod string to lift fluid.

pumping well

A well lifted by a downhole pump rather than flowing naturally or on gas lift.

pumping well tests

Tests on a pumped well, made from annulus pressure, from a dynamometer at surface, or by pulling the pump to run a gauge.

pumpoff

The condition where a pump draws down the fluid level to its intake and begins pumping gas or vapor instead of liquid.

purchase funnel

The buyer's progression from awareness to purchase.

purge

The process of removing vapors or contents from a vessel (such as an analyzer or sample cylinder) by filling and bleeding the entire contents.

purging

A procedure for removing combustibles from a furnace.

purifying respirator

A respirator filtering the ambient air rather than supplying its own.

push vs. pull communication

Sending information out against making it available for people to retrieve.

pushbutton

A momentary manual switch initiating an action.

pushbutton switch

A momentary switch operated by pressing.

pushdown

An apparent structural low on a seismic section caused by a low-velocity body above it.

pusher

The drilling contractor's senior supervisor at the rig, more fully the toolpusher.

PV

Plastic viscosity — the Bingham model's slope term, the flow resistance a mud gets from its solids and base fluid.

PVC

Polyvinyl chloride, a rigid plastic widely used for pipe and fittings in water and gas service, drains and vents, sewer piping and irrigation systems, and other applications.

PVT

Pressure, volume, temperature: the phase behavior of a reservoir fluid, and the laboratory program that measures it.

PVT analysis

Pressure-Volume-Temperature laboratory analysis in which researchers use various instruments and techniques to determine reservoir fluid behavior and properties from oil and gas samples.

PWM

Pulse Width Modulation (or Modulated): a common type of inverter drive.

PWM pulse

Pulse Width Modulation pulse. A single pulse of voltage that is part of a sequence of applied voltages used to drive a motor in a variable speed application.

pycnometer

A known volume and weight device used to prove the accuracy of a densitometer.

pyrite

Iron sulfide, whose presence affects resistivity logs and indicates reducing conditions.

pyrolysis

The controlled heating of a rock sample in an oxygen-free atmosphere to generate and measure its hydrocarbons.

pyrometer

A device used to measure temperature.

pyrophoric

Igniting spontaneously in air, as iron sulfide scale can when a vessel is opened.

pyrophoric chemical

A chemical that will ignite spontaneously in air at a temperature of 130F or below.

pyrophoric material

Any material that is capable of igniting spontaneously when it is exposed to air or oxygen.

pyrophosphate

A phosphate polymer made by heating an orthophosphate to drive off water, used as a mud thinner.

pyrrhotite

An iron sulfide mineral, formula close to FeS, magnetic and formed diagenetically under reducing conditions.