Discover the IHRDC Energy Glossary_beta

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B

back off

To unscrew a threaded connection downhole, usually to part the string above a stuck point before fishing.

back pressure regulator

A motor valve, operated by a control device that opens and closes to maintain set pressure on the meter tube.

back propagation

Reconstructing where and what shape a wavefield had at an earlier time by running the wave equation backwards — the principle behind migration.

back stripping

Removing layers from a section one at a time, decompacting each, to reconstruct the basin's subsidence and burial history.

back stroke

Movement of the compressor piston toward the drive unit.

back wash

To reverse the direction of flow through a screen, filter or gravel pack to clear material that has plugged it.

back-blasting

A cleaning process that uses air to remove accumulated cake from the bags of a baghouse.

back-pressure valve

A valve used to maintain design gas pressure, such as in a separator or a LACT unit, by maintaining a constant pressure and controlling the flow rate.

backarc

The region behind a volcanic arc, which can extend and form a basin.

backarc basin

The basin formed by extension behind a volcanic arc.

backflow

The reversal of fluid flow through a valve.

background gas

The steady baseline of gas carried in the circulating mud while drilling, against which any increase is read.

backplane

The printed circuit board at the rear of a PLC chassis or rack that contains communications and power buses for the PLC system modules, with sockets into which the modules are plugged.

backplate

The plate closing the back of a casing or housing.

backpressure

Pressure held against a flowing stream by whatever lies downstream of it, resisting the flow.

backpressure control valve

Valve holding pressure upstream of itself, protecting the process rather than the destination.

backscatter

Energy scattered back toward its source by a rough or inhomogeneous medium, rather than reflected coherently.

backstrip

Remove the effect of sediment load and compaction to recover true tectonic subsidence.

backsurging

Deliberately reversing flow briefly to clean perforations or a filter.

backup curve

A repeated curve on a log plotted at a shifted or compressed scale, so readings that go off the track can still be read.

backup ring

A supporting ring set behind an O-ring to close the extrusion gap, stopping the seal being forced out under high differential pressure.

backward curved fan

A type of centrifugal fan in which the blades are curved backward to promote smooth air flow.

backward inclined fan

A type of centrifugal fan in which the blades are sloped back from the direction of rotation.

backward multiple-contact test

A laboratory test contacting reservoir oil repeatedly with fresh enriched gas, tracing how the gas composition evolves toward miscibility.

backwardation

A market where prompt prices exceed forward ones, rewarding immediate delivery.

backwashing

Reversing the flow of liquid through a filter to clean off the filter medium.

bactericide

A biocide added to water-base mud to stop bacteria degrading the natural starches and gums in it.

bad hole

A borehole out of gauge or rugose, so contact tools lose their seating and log readings degrade.

baffle

A plate diverting or slowing flow inside a vessel or exchanger.

baffles

Devices inside a vessel, such as a reactor or separator, used to reduce the rate of flow, change the direction of fluids, and increase mixing efficiency.

baghouse

A filtering device containing rows of long cloth bags that are used to trap particulates from a gas or vapor stream.

bailer

A tube lowered on a line to recover fluid or debris from the wellbore.

bakken

The North Dakota shale play whose development helped define the United States tight oil boom.

balance beam element

A relay element, similar to a clapper element, that consists of a beam with a pivot, a moving contact, and a fixed contact.

balance drum

A device that is mounted onto a pump shaft at the discharge end to reduce the impact of axial thrust.

balance piston

A piston using discharge pressure to offset a compressor's or pump's axial thrust.

balance sheet

The statement of what a company owns and owes at a point in time.

balance-opposed compressor

A compressor with compression units on both sides of the same frame.

balanced array

An induction coil array arranged so that the direct transmitter-to-receiver coupling cancels, leaving zero reading in free space.

balanced draft furnace

A furnace that uses two fans: one to provide air for the burners and the other to remove the combustion gases.

balanced equation

A chemical equation with equal atoms of each element on both sides.

balanced plug

A cement plug placed through a work string so the slurry stands at the same level inside and outside the pipe, letting the string be pulled without disturbing it.

Balanced Scorecard

Kaplan and Norton's method of managing on financial, customer, process and learning measures together.

balanced-activity oil mud

An oil mud whose brine phase is salted to the same water activity as the shale being drilled, so no water moves either way.

balancing line

A line that runs from a balancing piston chamber to the suction line of a centrifugal pump.

balancing resistors

Resistors places on the non-inverting terminal of a differential amplifier, used to balance the resistance of the non-inverting terminal with the resistance of the inverting terminal.

ball catcher

A downhole assembly that catches and retains the balls dropped to actuate ball-operated tools.

ball check valve

A type of lift check valve that has a ball shaped disc.

ball diverter

A small sphere pumped with the treatment that seats on whichever perforation is taking most fluid, forcing the rest to take their share.

ball dropper

The surface device that releases ball sealers into the treating line at a controlled rate during a job.

ball launcher

Another term for a ball dropper — the device injecting ball sealers into the treatment stream.

ball operated

Said of a downhole tool actuated by dropping or pumping a ball onto a seat inside it.

ball sealer

A ball dropped to seal a perforation and divert treatment fluid to another interval.

ball sealers

Small spheres pumped with a treatment that seat on the perforations taking the most fluid, diverting the rest of the job to tighter ones.

A valve with a ball-shaped disc that has a hole through it. The ball is rotated a quarter turn to open or close the valve, providing a straight-through flow pattern. Typically used as a control device in low-pressure applications and not designed for throttling.

ballout

The condition in a ball diversion job when every open perforation has been sealed and injection stops entirely.

band

A defined interval of the spectrum — a range of frequencies or wavelengths treated as a single unit.

band pass

The range of frequencies a filter lets through, and the filter that passes them while rejecting energy above and below.

band reject

A filter that removes a defined band of frequencies while passing everything above and below it.

band width

A range of frequencies within a given band, in particular that used for transmitting signals.

band-limited function

A signal whose frequency content is confined to a finite band, with nothing outside it.

band-pass filter

A band-pass filter is a device that passes frequencies within a certain range and rejects frequencies outside that range.

bandwidth

The capacity at which a network can transmit data. Also, a measure of how well an oscilloscope responds to high-frequency signals, reported at the -3dB point where the displayed signal reduces to 70.7% of the applied signal. In amplifiers, it refers to the complete range of frequencies over which an op amp can amplify and provide its rated output.

bandwidth for 0.1 dB flatness

The range of frequencies within which the gain is 0.1 dB of the nominal value.

bank firing

Firing several guns run on one trip simultaneously rather than in sequence.

bank regulation

The rules governing bank capital, conduct and stability.

bank reputation risk

Exposure to loss of trust, which for a bank can be existential.

banking industry

The sector taking deposits, lending, and providing payment and financial services.

bankruptcy

The legal process for an entity unable to pay its debts.

bar graph

A graph that uses horizontal or vertical bars to represent numerical quantities, or a display on digital test instruments that provides an analog representation of the measured signal.

bar magnet

A permanent magnet in bar form.

bar sag

The droop of an alignment bracket under its own weight, which must be measured and subtracted.

barchan dune

A barchan dune is an arc-shaped sand ridge, comprising well sorted sand. A barchan dune possesses two "horns" that face downwind, with the downwind sloping slip face at the angle of repose of sand, approximately 32 degrees.

barefoot

Openhole — without casing across the interval, as in a barefoot completion or a barefoot drillstem test.

barefoot completion

A completion with the reservoir section left open, no casing or liner across it.

barefoot well completion

A barefoot well completion is a well completion that has no casing or liner set across the reservoir formation, allowing the produced fluids to flow directly into the wellbore.

barefoot well completions

A barefoot well completion is a well completion that has no casing or liner set across the reservoir formation, allowing the produced fluids to flow directly into the wellbore.

bargaining

Exchanging concessions to converge on terms.

bargaining approach

The chosen method of trading concessions toward agreement.

barge

A large, rectangular, flat-bottomed vessel that may be used to transport liquid products.

barge rail

The inland transport modes used where pipelines do not reach.

barite

A mineral consisting of barium sulfate, generally white or colorless, and the main source of barium.

barite plug

A slug of barite slurry spotted at the bottom of the hole, which settles into a dense solid mass.

barium

The element in barite, the weighting agent that gives drilling mud its density.

barrel

A measure of petroleum volume in the United States, equal to 42 U.S. gallons. Also, a cylindrical chamber in a pump into which well fluid flows and is displaced by a closely fitted plunger. In electrical work, the part of a terminal or connector where wiring is inserted during installation.

barrel cover

Part of the outer casing of a radially split pump that can be removed to gain access to the volute casing.

barrel equivalent

The 350 cm3 laboratory volume standing in for one 42-gallon barrel, so that a gram of additive represents a pound per barrel.

barrel of oil equivalent (BOE)

A measure used to aggregate oil and gas resources or production, with one BOE being approximately equal to 6,000 cubic feet of natural gas.

barrels of liquid per day

The daily total of oil and water a well produces.

barrels of oil per day

A production rate in 42-gallon barrels of crude per day, quoted for a well, a field or a whole portfolio. Abbreviated BOPD.

barrels of water per day

The daily volume of water produced by a well or a field.

Barret tray

A frame-like device that can be used to support a radially split pump's volute casing during removal and installation.

barrier island

A sand body parallel to shore, separated from it by a lagoon, and a good reservoir where preserved.

barrier management

Identifying the defenses that prevent or limit a major accident and verifying they still work.

baryte

The British spelling of barite, the barium sulfate mineral used to weight drilling fluid.

base

In electronics, the center element of a bi-polar transistor. In chemistry, a substance that releases hydroxyl ions when added to water.

base drilling mud

The fluid a mud is built from, before solids and chemicals.

base exchange

The swapping of one cation for another on a clay's exchange sites, altering how the clay hydrates and swells.

base log

The log chosen as the depth reference for a well, to which every other run is tied.

base map

A map carrying the fixed reference information — coordinates, culture, well and line locations — on which data and interpretations are plotted.

base mud

The drilling fluid before weighting and treating chemicals are added.

base of weathering

The lower boundary of the near-surface low-velocity layer, below which seismic velocity rises sharply.

base permeability

The effective permeability to the non-wetting phase (usually hydrocarbon) at irreducible wetting phase saturation.

base slurry

The conventional cement slurry a foamed cement is made from, before gas is injected into it.

base station

A fixed reference point of known position or field value, against which moving or repeated measurements are corrected.

base ten number system

A number system that uses the digits 0 through 9.

baseline

A reference level against which deflections are measured — on an SP log, the straight line the curve holds opposite thick shale.

basement

The rock below which no economic reservoir is expected — economic basement, which need not be crystalline.

baseplate

The mounting plate supporting equipment on a foundation.

bases of leadership

The foundations from which a leader draws standing and effect.

basic application (competency level 2)

Able to describe the task, process or element / Can perform simple or routine activities without supervision / Has basic understanding of procedures / Participates in routine implementation of field applications / Elevates complex situations to appropriate person.

basic sediment

Impurities such as sand, clay, etc., now called sediment in A.P.I. publications.

basic wavelet

The wavelet shape produced by reflection at a single interface with a positive reflection coefficient — the building block of a synthetic trace.

basin

A large, natural depression on the Earth's surface in which sediments, generally brought by water, accumulate.

basin analysis

The integrated study of a basin's formation, fill and petroleum systems.

basin classification

Grouping basins by their tectonic origin, which predicts their fill and their petroleum systems.

basin development

How a basin formed and filled, which controls where source and reservoir rock sit.

basin fill

The sediment accumulated in a basin.

basin formation

The process creating room for sediment, whether by extension, flexure or thermal contraction.

basin margin

The edge of a basin, where sediment is coarsest and traps are often stratigraphic.

basin starvation

Basin starvation refers to a period when land-derived sediment is not deposited. This process results in distinct sedimentary cycles, where land sediment fills the basin during low sea levels and shifts to shelf or marine deposition during high sea levels.

basin subsidence

The sinking that creates room for sediment to accumulate.

basinal

Deposited in the deeper part of a basin, typically fine grained and organic rich.

basinward

Toward the basin center, the direction of progradation.

basis of design

The agreed technical premises on which detailed engineering proceeds.

basis risk

The residual risk that the hedge and the physical position do not move exactly together.

basket

A downhole tool that catches and retains debris or dropped objects — junk, balls, darts or plugs.

basket flowmeter

A production logging spinner enclosed in a collapsible basket that diverts the whole flow through it, so low rates still register.

basket sub

A sub with an open catcher above the bit that traps junk circulated up from the bottom of the hole.

batch blending

Blending in which components are taken directly from process units or from individual rundown tanks and blended in a blend tank.

batch mixer

A vessel that mixes an entire treatment volume at once, so the fluid can be checked and adjusted before any of it is pumped.

batch treatment

Pumping a measured quantity of treatment chemical in one go, rather than injecting it continuously.

batching

Moving different products through one pipeline in sequence as discrete parcels.

bathyal

Pertaining to the ocean environment of the continental slope, between roughly 200 m and 2,000 m water depth.

bathymetry

Bathymetry maps depict the submerged topography and physiographic features of ocean and sea bottoms. Their primary purpose is to provide detailed depth contours of ocean topography as well the size, shape and distribution of underwater features.

BATNA (Best Alternative to a Negotiated Agreement)

What a party will do if no deal is reached, which sets the real limit of what it should accept.

battery

A group of similar units of equipment installed together — a separator battery, a tank battery, a filter battery.

battery charger

Equipment maintaining a battery's charge from an alternating supply.

battery site

The surface location where a lease's separators, treaters, tanks and pumps are grouped, also called a tank battery.

battery voltage

The voltage a battery is delivering, which falls as it discharges.

Bayesian inference

Updating the probability of a hypothesis as new evidence arrives, using Bayes's theorem.

Bayesian method

An approach that starts from a prior distribution and updates it with new data to give a posterior distribution.

Bayesian probability

Probability interpreted as a degree of belief that is revised as evidence arrives, following Bayes's theorem.

BBL

One stock tank barrel, of 42 U.S. gallons liquid volume, used in reference to crude oil, bitumen, condensate or natural gas liquids.

BBL or bbl

The oilfield barrel, a volume of 42 US gallons or 0.159 cubic meters, and the standard unit for liquid hydrocarbon volumes.

Bc

Bearden units of consistency, the scale on which cement slurry consistency is measured in a consistometer.

BCD

Binary Coded Decimal number expressed in a coded binary format. The number 123 expressed in BCD is 0001 0010 0011.

BCF

One billion cubic feet of natural gas.

Bcf/d

Billion cubic feet per day: the rate unit for large gas production, whether from a field, a play or a pipeline.

bead tracer

An insoluble radioactive plastic sphere injected to trace where fluid, rather than dissolved tracer, actually goes.

beaker

A straight-sided laboratory vessel for holding and mixing liquid.

beam

The heavy pivoted steel member of a beam pumping unit, converting the crank's rotation into the reciprocating stroke of the sucker rods.

beam pump

A sucker-rod lift system in which a surface beam unit reciprocates a rod string that drives a downhole pump.

beam pumping unit

The walking-beam surface unit converting rotary drive into the reciprocating stroke a rod pump needs.

beamform

Beamforming or spatial filtering is a signal processing technique used in sensor arrays for directional signal transmission or reception.

bean

A fixed or adjustable choke at the wellhead that sets the flow rate.

bean choke

A fixed-orifice choke fitted at the wellhead to hold the well at a set rate.

Bearden units of consistency

The unit in which cement slurry consistency is measured on a consistometer, abbreviated Bc.

bearing cartridge

A device that holds the bearing at one end of the worm shaft inside a motor operator.

bearing housing

The housing that encloses a pump's shaft bearings.

Beaufort scale

The 0 to 12 scale relating wind force to observable sea and land conditions, devised by Admiral Francis Beaufort.

bed

A single layer of sediment or sedimentary rock, distinguishable from the layers above and below it.

bed boundary

The contact between two beds, whose sharpness limits log resolution.

bed reactor

A reactor holding catalyst as a bed the feed passes through.

bed thickness

The thickness of a bed measured perpendicular to its bounding surfaces.

bed wrap

The innermost layer of tubing or line wound directly onto the reel core.

bedding layer

The term bedding layer, which is also termed stratification, ordinarily describes the layering that occurs in sedimentary rocks. Bedding layers are greater than one centimeter in thickness, whereas laminations are less than one centimeter thick.

bedding plane

The surface that separates one stratum, layer, or bed of stratified rock from another.

bedding plane, bed

The surface that separates one stratum, layer, or bed of stratified rock from another.

bedding plane, bed, bedding

A bedding plane is the surface that separates one stratum, layer or bed of stratified rock from another.

bedrock

Solid rock, whether exposed at surface or lying beneath soil, unconsolidated sediment and weathered rock.

behavioral and soft skills

Competencies that identify individual characteristics expected of individuals to function competently in the specific position, including interpersonal and people-oriented skills, team skills, leadership skills and essential internal attributes.

behavioral interviewing

Asking what a candidate actually did before, on the premise that it predicts future performance.

bell nipple

A flared section at the top of the casing or BOP stack that guides tools into the hole and routes returns to the flowline.

bellow

A flexible corrugated element accommodating movement or sealing a moving stem.

bellows pressure element

A thin-walled, corrugated, accordion-shaped metal tube that expands and contracts in response to changes in pressure.

belonging

The feeling of being accepted as oneself, which is what inclusion is trying to produce.

belt effect

The extra drag on a line in a deviated well as it is pulled against the inside of a bend, like a belt on a pulley.

bench grinder

A power grinder with a wheel on each end of a motor-daven shaft. Usually mounted on a work bench or a stable, freestanding pedestal.

benchmark

A permanently fixed survey marker of known position and elevation, cited as a reference for other measurements.

benchmark crude

A widely traded crude whose price references others.

benchmarking

Comparing performance against others to establish what is achievable.

benchmarking study

Comparing costs and terms against peers to establish whether current arrangements are competitive.

bend length

The amount of conduit that is used to complete a bend.

bend radius

The measure of how fiat or how sharp the curve of a bend is.

beneficiate

To upgrade a mineral or ore by removing impurities, so it meets the specification for its intended use.

beneficiation

Chemical or mechanical treatment that upgrades a mineral or ore for its intended use.

benefits program

The package of non-cash provisions offered alongside pay.

Benioff zone

The dipping zone of earthquakes that marks a subducting oceanic plate as it descends beneath the overriding plate at a convergent margin.

benthic

Pertaining to organisms living on or in the bed of a body of water, and to that environment.

benthos

The organisms living on or in the bottom of a body of water.

bentonite

A clay composed mainly of montmorillonite, used to build viscosity in water-base mud and as an extender in cement.

bentonite clay

The swelling clay giving water-based mud its viscosity and filter cake.

benzene

The simplest aromatic, a major petrochemical feedstock and a regulated carcinogen.

benzene ring

The six-carbon aromatic ring, stable and the basis of aromatic chemistry.

berth

The place at a terminal where a ship moors to load or discharge.

best alternative to a negotiated agreement (BATNA)

What you will do if no deal is reached, which sets what you should accept.

best practice (BP)

A process or activity that has been shown in practice to be the most effective.

beta

The ratio of the change in base current to the change in collector current of a transistor; current gain in the common emitter circuit configuration.

bevel

An angled edge, cut on pipe ends to prepare a weld.

bevel gear

A type of gear that is used to transmit power from one shaft to another shaft that is usually set at a 90-degree angle.

bevel-gear-operated (BGO) valve

A gate valve whose handwheel drives the stem through a bevel gear set, multiplying the torque available.

bfoe

Brent, Forties, Oseberg and Ekofisk, the crude grades making up the Brent benchmark basket.

BGG

Background gas — the steady level of gas in the returns while drilling a uniform section, against which shows are judged.

BHA

The bottomhole assembly: the lowest part of the drillstring, running from the bit up through stabilisers, collars, motors and jars to the drillpipe.

bhas

Bottomhole assemblies, the tool arrangements above the bit.

BHCT

Bottomhole circulating temperature: the temperature a cement slurry meets as it is placed, and the temperature at which thickening time must be tested.

bhgm

The borehole gravity meter, which measures density far from the wellbore.

BHP

Bottomhole pressure: the pressure exerted against the formation at the bottom of the well, which flowing pressure must exceed for fluid to reach surface.

BHST

Bottomhole static temperature: the temperature of the undisturbed formation at total depth, reached once circulation has stopped long enough for it to equilibrate.

BHT

Bottomhole temperature: the temperature measured in the borehole at total depth, usually from maximum-recording thermometers run with the electric logs.

bi-metallic strip

A strip of two different metals bonded together. When the strip is heated, the metals expand at different rates, causing the strip to bend.

bi-polar transistor

A transistor in which the poles are made of the same type (N or P) material; N-P-N or P-N-P transistors.

bias

A bulk shift of the null point in seismic processing, changing the balance of positive against negative excursions on a display.

bias in a data set

Systematic error making a sample unrepresentative of what it is taken to describe.

bias voltage

A steady voltage applied to set a device's operating point.

bias weld

The angled weld joining two strips of steel end to end during coiled tubing manufacture.

bicarb

Sodium bicarbonate, used to treat calcium contamination in a water-base mud.

bicarbonate

A compound containing the bicarbonate ion, HCO3-.

bicenter bit

A bit with an offset reaming section that drills a hole larger than its own pass-through diameter.

bichromate salt

A dichromate salt such as potassium dichromate, used as an oxidizing corrosion inhibitor.

bid and study agreement

An agreement letting two or more companies jointly review data and decide whether to bid on acreage together.

bid list

The set of suppliers invited to tender, whose composition largely determines the outcome.

bid solicitation

The act of inviting offers from the market.

bidirectional

Working in either direction, which for a prover means it can be proved on both strokes.

bidirectional pipe prover

A pipe prover proved on the stroke in either direction, halving the runs needed.

bidirectional prover

A physical prover in which the fixed volume is determined by the displacer making a round trip.

big data

Datasets too large or too varied for conventional tools, needing distributed storage and analysis.

big data strategy

A deliberate plan for which data to collect, keep and exploit, rather than storing everything.

big hole charge

A shaped charge designed for entrance hole diameter rather than depth of penetration.

bilinear flow

The flow regime in a fractured well where linear flow along the fracture and linear flow from the formation into it occur at the same time.

bill lading

The shipping document evidencing receipt of cargo and carrying title.

bill of lading

The shipping document that evidences receipt of cargo and carries title to it.

bill of lading date

The loading date on that document, which usually sets the pricing period for the cargo.

billion cubic feet

A unit for large volumes of natural gas, abbreviated Bcf.

billion cubic feet per day

A unit for large rates of natural gas production, abbreviated Bcf/d.

bimetallic

Made of two bonded metals with different expansion rates, which bends predictably with temperature.

bimetallic corrosion

Accelerated corrosion of the less noble of two dissimilar metals in electrical contact in an electrolyte.

bimetallic thermometer

A temperature measurement device containing two different metals that expand and contract at different rates.

bimetallism

The electrical potential generated between two dissimilar metals in contact, which drives galvanic corrosion.

bin

A large rectangular, cylindrical, or spherical vessel, with a relatively broad cross-section and either an open top or a closed top.

binary

A discrete device having two states. Also, the base two numbering system.

binary numbering system

The numbering system based on powers of two.

binary tower

A distillation tower that separates a feed into two products.

Bingham plastic model

A two-parameter rheological model for a fluid that will not flow until a yield stress is exceeded, then thins linearly with increasing shear rate.

binning

Grouping seismic traces by their common midpoint before stacking.

bins

The cells a seismic survey area is divided into, each collecting the traces whose midpoints fall inside it.

bioaccumulation

The build-up of a substance within an organism to a concentration higher than in its surroundings.

bioassay

A toxicity test exposing living organisms, commonly mysid shrimp, to a substance to measure its effect.

biochemical oxygen demand (BOD)

A measure of how much oxygen is needed for the micro-organisms in activated sludge to decompose organic matter in wastewater.

biocide

Any substance that kills or inhibits micro-organisms, added to water systems and muds to stop biological growth and degradation.

biocides

Chemicals that are added to water to kill micro-organisms.

bioconcentration

The accumulation of a substance in an organism to a level above that of the surrounding water.

biodegradation

The breakdown of complex molecules by micro-organisms into simpler compounds.

biodiesel

A diesel substitute made from vegetable oil or animal fat.

bioenergy

Energy from recently living biomass, counted as low-carbon because the carbon released was recently absorbed.

biofuel

Fuel made from biomass rather than from fossil hydrocarbons.

biofuels

Liquid fuels made from biomass, used to lower transport emissions within existing engines.

biogas

Methane-rich gas from anaerobic digestion of waste, upgradable to pipeline quality.

biogenic

Refers to something that is produced or brought about by living organisms, encompassing any constituents, secretions, and metabolites of plants or animals.

biohazard bags

A plastic bag, usually red and imprinted with the international biohazard symbol, designed for materials contaminated with blood or other infectious materials.

biohydrogen

Hydrogen produced by living organisms rather than by thermal or electrical means.

biologic

Of organic origin, as the material that becomes source rock.

biomarker

An organic molecule retaining its biological structure, used to tie oil to its source rock.

biomarkers

Molecular fossils in oil that fingerprint its source rock and maturity.

biomass energy

Energy from organic material, counted as low-carbon where the feedstock regrows.

biomass gasification

Converting organic matter to syngas with heat and limited oxygen, rather than burning it outright.

biomass material

Organic matter used as feedstock, whose moisture and ash content decide which conversion route suits it.

biopolymer

A polymer produced by bacterial fermentation, such as xanthan gum, used to build viscosity in drilling and completion fluids.

biopolymers

Naturally derived polymers used to build viscosity in drilling and completion fluids.

biostratigraphic

Pertaining to the use of plant and animal fossils to date strata and correlate them between locations.

biostratigraphic correlation

Matching strata between wells using their fossil content.

biostratigraphic zones

Biostratigraphic zones are intervals of geologic layers that are defined on the basis of their fossil assemblage.

biostratigraphy

Biostratigraphy is the application of plant and animal fossils to date and correlate geological strata.

Biot theory

Biot's theory of wave propagation and deformation in a fluid-saturated porous elastic solid.

biota

Biota refers to the animal and plant life of a particular region, habitat or geological period.

biotic

Biotic refers to the living or once-living components of an environment, including all organisms, from microscopic bacteria to macroscopic plants and animals, as well as their waste and remains. It encompasses anything that is, or was, alive within a specific ecosystem or geological setting.

bioturbation

The reworking of soils and sediments by animals, and sometimes by plants. Bioturbation structures are patterns such as tracks, trails, burrows, and mounds created in sediments by the activity of living organisms, also known as trace fossils when found in ancient rocks.

bioturbation structures

Bioturbation structures are patterns created in sediments by the activity of living organisms, such as tracks, trails, burrows, and mounds. These structures are also known as trace fossils when found in ancient rocks.

biphasic

Involving two immiscible fluid phases flowing together.

bird

A towed housing carrying a magnetometer behind an aircraft, or a depth-control device clamped to a marine streamer.

birdcage

A birdcage is an outer armour distortion of a wireline logging cable.

birefringence

The splitting of a wave into two components of different velocity and orthogonal polarization as it enters an anisotropic medium.

bistable multivibrator

A multivibrator that has two stable states.

bit

A single binary digit of information that has a value of either I or 0 and is used to represent an on/off or active/inactive state.

bit address

An address that refers to a single bit of a memory word.

bit balling

Bit balling is a phenomenon that occurs in drilling operations when drilling in soft, sticky formations. The drilled material (cuttings) accumulates in the bit, forming a ball or clump that reduces and potentially stops the bits ability to cut formation rock and progress the borehole.

bit box

A lockable steel container in which drill bits are stored and transported.

bit breaker

A slotted plate seated in the rotary table that grips the bit so its connection can be torqued without the bit turning.

bit nozzle

A hard-metal orifice in the bit face through which mud jets at high velocity to clean the cutters and lift cuttings off bottom.

bit record

The record of how each bit performed in a well — footage, rotating hours, penetration rate and dull grading.

bit resistivity

A resistivity measurement taken at or immediately behind the bit by an LWD tool, giving the earliest possible reading of the formation.

bit trip

A round trip made solely to change out a worn or underperforming bit.

bitumen

A highly viscous form of crude oil (greater than 10,000 centipoise) resembling cold molasses (at room temperature). Bitumen must be heated or combined with lighter hydrocarbons for it to be produced. Contains sulfur, metals and other nonhydrocarbons in its natural form.

bivariate analysis

Analysis of two variables together, to establish whether they are related and to describe the relationship.

black list

The OSPAR category of chemicals judged unsuitable for offshore discharge under any circumstances.

blade

A rotating or fixed part of a turbine. Rotating blades convert steam energy into mechanical energy, which rotates the turbine shaft; fixed blades direct steam into the rotating blades.

Blaine fineness

The specific surface area of a cement, in cm2/g, measured by how readily air passes through a packed bed of it.

bland coring fluid

A coring fluid formulated to leave the rock's wettability unchanged and to give minimal filtrate invasion.

blank

See Blind.

blank pipe

Plain, unperforated pipe run in a completion to space out components or to extend a screen assembly.

blanket gas

A gas cushion held above a liquid in a tank or vessel to keep air out.

blanketed tank

A tank that has been modified to maintain a layer, or blanket, of inert gas above the liquid in the tank.

blanking or blinding

The absolute closure of a pipe, line, or duct by the fastening of a solid plate (such as a spectacle blind or a skillet blind) that completely covers the bore and that is capable of withstanding the maximum pressure of the pipe, line, or duct with no leakage beyond the plate.

blast joint

A heavy-walled tubing joint set opposite perforations to resist erosion where produced fluid jets against the string.

blast sleeve

A hardened internal sleeve fitted to protect equipment from erosion by fluid jetting through perforations.

blasting cap

A small, sensitive, electrically fired charge used to initiate a larger and less sensitive explosive.

blebs

Bleb refers to a small, bubble-like inclusion of one mineral that is trapped within a larger mineral; essentially a tiny pocket of a different mineral material embedded within another mineral's matrix.

bleed off

To release pressure from a vessel, line or annulus in a controlled way.

bleed valve

Small valve releasing pressure or draining a dead leg, for service rather than for control.

bleed-off circuit

A flow control circuit that controls the amount of fluid going to an actuator by metering fluid that is bled off to the reservoir.

bleeder

A small valve or line releasing pressure or venting trapped fluid.

bleeder valve

A valve that is commonly used to release, or bleed, pressure from a tank.

bleeder valves

Valves installed on product lines and used for sampling and for bleeding air out of the lines.

bleedoff line

The valved line through which pressure is deliberately released from a vessel, string or manifold.

blend component

A stream blended into a finished product to bring a property within specification.

blend components

Components that are mixed, or blended, together in order to produce a product.

blend control computer

A computer that processes data from control variables and adjusts the blend as necessary during an in-line blending process.

blend header

Part of an in-line blending system in which a static mixer mixes the blend components together.

blend recipe

Instructions that give the exact blend components and proportions to be used to blend a specific product.

blend tank

A tank used for mixing and storing intermediate products or finished products, including the tank in a batch blending system where blend components are mixed together.

blended crude

A mixture of two or more crude streams combined to meet a specified gravity, sulfur content or other property.

blended learning

The practice of using several media in one curriculum. It combines traditional face-to-face learning and e-Learning to create a more holistic, effective training system. It leverages the best in-person learning experiences with online learning to provide a comprehensive, multi-method approach to learning and development.

blender

The unit that mixes gels, slurries and solids into the treating fluid at the wellsite.

blending

Mixing two or more components to produce a product.

blending area

The part of the plant where products are blended.

blending bonus

A factor, resulting from component interaction, that causes a higher road octane than the weighted average road octane of blend components.

blending negative

A factor, resulting from component interaction, that causes a lower road octane than the weighted average road octane of blend components.

blending octane numbers

Octane numbers that allow for blending bonuses and blending negatives that result from the interaction of blend components.

blending operation

Combining streams to make a product meeting specification.

blendstock

A component blended with others to make a finished product to specification.

blind

A solid metal plate or disk inserted between pipe flanges to completely block off and isolate a line or piece of equipment, prohibiting flow in either direction. Also called a blank.

blind box

A solid metal slickline tool run to push down on, or jar against, something in the well.

blind flange

A full-rated flange fitting used to blind or cap the flanged end of an open pipe or valve.

blind list

A list of all blinds (or blanks) installed to isolate equipment. It can also contain other isolation procedures. It documents installation and removal requirements.

blind ram

A ram BOP element with a flat face that seals the open bore when no pipe is across it.

blind rivet

A non-threaded fastener that is used to join pieces when only one side of a joint can be reached.

blind shear ram

A BOP ram that cuts the pipe in the hole and then seals the open bore completely.

blind spot

An area to the rear and side of a vehicle that cannot be seen by looking in the rear view mirror or side view mirrors.

blind zone

A layer that refraction seismic cannot detect, usually because its velocity is lower than the rock above so it never produces a first arrival.

blind ﬂange

A solid steel disc with bolt holes; used to close off the end of a pipe or, on the side of a pipe, for easy access to the inside of the pipe.

block

A set of sheaves in a housing, used with line to gain mechanical advantage — the crown block and travelling block of a hoisting system.

block and bleed valve

A valve which shuts off flow in a meter tube and the seal of the valve can be checked by draining the valve.

block and tackle

A lifting device that uses two blocks and multiple pulleys, called sheaves, to create a mechanical advantage.

block diagram

A diagram in which blocks are used to represent the major components in a system or the basic steps in a process.

block faulting

Faulting that breaks the crust into discrete tilted blocks.

block gauge

A type of calibration gauge machined to an exact size; available in three grades.

block spade terminal

A spade terminal in which the tips of the forked tongue are angled. When the terminal is installed in a terminal block the terminal butts against the barrier of the block.

block valve

An on-off valve used to isolate a line or a piece of equipment, rather than to regulate flow through it.

blockage

An obstruction restricting flow in pipe, perforation or pore.

blocking in

The process of closing all valves so that flows can neither enter nor leave a tank; also called isolating. Also includes lockout and tagout of valves for the tank and its associated equipment and lines, as well as blinding valves at the lines to and from the tank and disconnecting the tank and its auxiliary equipment from their energy sources.

blood

Human blood, human blood components and products made from human blood. It also includes the liquid that can ooze from wounds.

blood components

Plasma, red blood cells, white blood cells and platelets.

blood hazards

Chemicals that decrease hemoglobin function or deprive the body tissues of oxygen.

Bloom's taxonomy

A hierarchical ordering of cognitive skills established by Benjamin Bloom in 1956. IHRDC uses Bloom's taxonomy as a guide to writing behavior statements with increasing verb complexity across the four competency levels. See also, Proficiency statements.

blow-by

Gas escaping with the liquid from the bottom of a separator when the liquid seal that should hold it back is lost.

blowdown

The intentional removal or release of water, liquid, and solids from a system such as a boiler or cooling tower during operation, in order to control water chemistry and remove accumulated salts, deposits, and other impurities that could cause foaming and fouling.

blowdown valve (BDV)

A valve that on activation depressurizes a system by venting its contents to flare or atmosphere.

blowing the drip

Opening a drip pot on a gas line to expel the liquids that have collected in it.

blown asphalts

Asphalts that are produced by forcing hot air into soft grades of asphalts in order to make the asphalt harder.

blown fuse

A fuse that has melted to interrupt an overcurrent.

blowout

An oil well blowout is an uncontrolled release of crude oil. Blowouts occur when pressure-release systems fail.

blowout preventer

A large valve assembly at the top of a well that can be closed to contain formation fluids when well control is lost.

blowout preventer bop

The valve stack sealing the well if it begins to flow uncontrolled.

blowout preventer stack

The assembled set of rams and annular preventers at the wellhead.

BLPD

Barrels of liquid per day: a well's total production of oil and water together.

blue hose

Shielded twisted pair cable commonly used for PLC network connections.

blue hydrogen

Hydrogen made from natural gas with the resulting carbon dioxide captured and stored.

blueprint

A reproduction of an original drawing of a structure or a component; sometimes referred to as a construction drawing or a working drawing.

BM

Benchmark — a permanent marker of surveyed position and elevation to which other survey work is referenced.

board of directors

The body accountable to owners for the company's direction and control.

body language

Posture, gesture and movement, which carry meaning independently of words.

body relief valve (BRV)

A small relief valve on a ball valve that vents the body cavity if trapped liquid expands with temperature.

body wave

A wave travelling through the body of a medium rather than along an interface — the P and S waves of seismology.

BOED

Barrels of oil equivalent per day.

boem

The United States Bureau of Ocean Energy Management, which leases and regulates offshore acreage.

boil off

The portion of LNG that vaporizes in storage or transit.

boil up rate

The rate of heat input to a distillation column from a reboiler.

boil-off gas

The portion of LNG that vaporizes in storage or transit, used as fuel or reliquefied.

boiler

The component in a fossil fuel power plant that burns fuel to produce heat and uses that heat to convert water into steam.

boiler component

A part of the boiler assembly.

boiler drum

The vessel where steam and water separate in a boiler.

boiler feed pump

The pump delivering water to the boiler against full drum pressure.

boiler feedwater

The treated water fed to a boiler, whose oxygen and hardness must both be removed.

boiler flame

The flame in the boiler furnace, monitored because loss of it with fuel still flowing is an explosion.

boiler fuel

The fuel fired in a boiler.

boiler furnace

The chamber where fuel is burned in a boiler.

boiler load

The demand for steam from a boiler.

boiler operation

Running a boiler within its firing, level and pressure limits.

boiler operator

The person licensed to operate a boiler.

boiler steam

The steam a boiler produces.

boiler stop valves

Valves used to isolate the boiler from the turbine, if needed.

boiler system

The boiler with its feedwater, fuel, air and steam circuits.

boiler trip

The stopping of all fuel flow to the boiler and the stopping of the ignitors.

boiler tube

The tube carrying water or steam through the boiler's heated zone.

boiler water

The water circulating in the boiler, whose chemistry decides whether tubes scale or corrode.

boiling liquid expanding vapour explosion (BLEVE)

The violent rupture of a vessel whose contents flash to vapor when containment fails.

boiling point

The temperature and pressure at which a liquid changes to a vapor.

boiling point percentage

The percent of a product that has vaporized at a particular temperature.

boiling point temperature

The temperature at which a fraction vaporizes, the basis of distillation separation.

boiling range

The temperature span over which a fraction distills, which defines the product.

boiling temperature

The temperature at which a liquid boils at a given pressure.

boilup rate

The rate of heat input to a distillation column from a reboiler.

bolt

A metal rod or pin for fastening objects together. A bolt usually has a head at one end and threads at the other and is secured by a nut.

bolt hole

The drilled hole a bolt passes through.

Boltzmann probability distribution

The distribution giving the probability that a system at a given temperature occupies a particular energy state, falling exponentially as that energy rises.

bomb

A pressure vessel used to capture and hold a fluid sample at pressure.

bond log

An acoustic log reading the amplitude of a signal travelling in the casing wall, from which the quality of the cement bond is inferred.

Bond number

The dimensionless ratio of gravitational to interfacial tension forces acting on a fluid.

bonnet

The part of a valve that closes the body, guides the stem and carries the stem packing or the operator.

Bonny Light

Nigeria's benchmark light sweet crude, prized for its high distillate yield.

bonus consideration

The cash paid to the mineral owner at lease signing, independent of any later royalty.

bonus payments

The host government agreement typically requires payments at key milestones throughout the exploration and production phases. A Signature Bonus payment is made when the initial agreement is executed; Discovery Bonuswhen a discovery is made; Initial Production Bonus when production begins; and perhaps others as higher levels of daily or cumulative production are achieved.

boolean algebra

A mathematical system of logic functions named after George Boole, in which variables have only the values "true" (1) and "false" (0), with associated operators such as AND, NAND, NOT, OR, and NOR.

boolean expression

An expression that uses letters and logical operators to represent a logic function.

Boolean simulation

Object-based modeling in which geological bodies of defined shape are placed into a background until the model matches the target proportions.

boom angle

The angle between the horizontal plane and the centerline of a crane's lower, or base, boom section.

boom point elevation

The vertical distance from ground level to the centerline of a cranes main boom point shaft.

booster

A small charge of secondary explosive crimped onto detonating cord to reliably initiate the next charge in the train.

booster pump

A pump raising pressure in an existing flow rather than establishing it.

BOP

Blowout preventer: a large valve assembly at the top of a well that can be closed to contain formation fluids when well control is lost.

BOP stack

The assembled set of blowout preventers — annular and ram units — at the wellhead, forming the closing element of the well control system.

BOPD

Barrels of oil per day: the standard rate unit for crude oil production.

borax

Borax is a white compound which occurs as a mineral in some alkaline salt deposits.

borehole

A hole in the earth made by a drilling rig.

borehole breakout

Borehole breakout is the enlargement of a borehole from a regular circular shape.

borehole breakouts

Borehole breakout is the phenomenon of the failure in the borehole rock when subjected to drilling activities, caused by in situ stress concentrations in the vicinity of the borehole that exceed the material strength.

borehole compensated

Borehole compensation is an upgoing and downgoing arrangement of transducers in a logging tool to offset spurious changes in readings caused by variations in the borehole size or the sonde tilt.

borehole compensation

A transmitter and receiver arrangement measuring both up and down the tool, so that changes in borehole size and sonde tilt cancel out.

borehole condition

The state of the hole — size, rugosity, mud — which determines log quality.

borehole correction

The adjustment applied to a log to remove the borehole's own contribution to the reading.

borehole diameter

The hole size, which affects log response, cement volume and casing selection.

borehole environment

The mud, temperature and hole condition that affect every downhole measurement.

borehole fluid

Whatever fluid fills the hole at the time of measurement.

borehole gravity

Measurement of the Earth's gravity field at stations down a wellbore, giving rock density averaged over a large volume around the hole.

borehole gravity meter

A logging instrument making relative gravity measurements at stations along a borehole, with sensitivity and repeatability in the microgal range.

borehole image

A picture of the borehole wall built from dense resistivity or acoustic measurements.

borehole imaging

Borehole imaging refers to those logging and data processing methods that are used to produce centimeter-scale images of the borehole wall and the rocks that make it up.

borehole imaging tool

A tool producing a picture of the hole wall, acoustically or electrically.

borehole imaging, borehole imagers

Borehole imaging devices are high resolution logging tools that produce maps of physical measurements of the rocks exposed on the borehole wall. They are thus two-dimensional logs, with depth and azimuth as independent variables. Three main imaging techniques are: ultrasonic reflection; electrical scanning; optical scanning.

borehole measurement

A measurement made in the hole rather than at surface.

borehole orientation

The direction of the borehole, described by its inclination and azimuth.

borehole rugosity

Borehole rugosity is the roughness, or unevenness, of a borehole.

borehole seismic data

Seismic data recorded with source or receivers in a well — check-shot, VSP, crosswell or single-well imaging.

borehole stability

Whether the hole stays open, governed by the balance of mud weight against rock strength.

borehole televiewer

An ultrasonic imaging tool whose rotating transducer scans the borehole or casing wall to build an acoustic image.

borehole wall

The exposed rock face of the drilled hole, imaged and measured by logging tools.

borehole, wellbore

The wellbore itself, including the open hole or uncased portion of the well. Borehole may refer to the inside diameter of the wellbore wall—the rock face that bounds the drilled hole.

Born method

An induction log response model that treats each formation element as a small perturbation on a uniform background conductivity.

borrow trenches

A hole, pit or excavation that has been dug for the purposes of removing gravel, clay and sand used in a construction project such as when building an overpass or embankment.

bottle test

A bench test dosing candidate demulsifiers into bottled samples of an emulsion to see which breaks it best.

bottom ash

The solid, non-combustible material that falls to the bottom of a boiler.

bottom hole assembly

A bottom hole assembly (BHA) is the lower part of the drill string, extending up from the bit to the drill pipe. The assembly can consist of drill collars, stabilizers, reamers, shocks, hole openers, and the bit sub and bit.

bottom log interval

The deepest depth at which the log readings are valid, at or above the bottom of the logged interval.

bottom sample

A sample drawn from the lowest point of a tank, a pipeline or a standing fluid column.

bottom water injection

Injecting water into the aquifer below the oil to maintain pressure.

bottomhole

At the bottom of the wellbore, where pressure and temperature are measured.

bottomhole assembly

The bottomhole assembly (BHA) is the lowest part of the drill string, extending from the bit up to the drill pipe. The assembly can consist of drill collars, subs such as stabilizers, reamers, shocks, hole-openers, and the bit sub and bit.

bottomhole assembly (BHA)

The bottomhole assembly (BHA) is the lowest part of the drill string, extending from the bit at the bottom of the borehole up to the drill pipe. A BHA can consist of such elements as drill collars, stabilizers, reamers, shocks, hole openers, the bit sub, and drill bit.

bottomhole choke

A fixed restriction set in the tubing near the reservoir to take part of the pressure drop downhole.

bottomhole circulating

The temperature or condition at the bottom of the hole while circulating.

bottomhole circulating temperature

The temperature a cement slurry meets as it is placed, and the temperature at which thickening time must be tested.

bottomhole flowing

The condition at the bottom of the hole while the well produces.

bottomhole flowing pressure

Pressure at the sandface while producing, the quantity inflow performance is measured against.

bottomhole gas separator

A perforated tube below a rod pump that lets gas break out and rise up the annulus instead of entering the pump.

bottomhole heater

A downhole electrical or fired heater that raises produced fluid temperature at the bottom of the well.

bottomhole injection pressure (BHIP)

The pressure at the formation face during injection of a treatment or of injected fluid.

bottomhole pressure

The pressure exerted against the formation at the bottom of the well, which flowing pressure must exceed for fluid to reach surface.

bottomhole sampler

A tool run on wireline to capture a fluid sample at depth, at reservoir pressure and temperature.

bottomhole shut-in

Closing a well with a valve set just above the producing interval rather than at surface.

bottomhole static temperature

The temperature of the undisturbed formation at total depth, once circulation has stopped long enough for it to equilibrate.

bottomhole temperature

The temperature measured in the borehole at total depth at the time of measurement.

bottoms product

The heavier liquid product with a higher boiling temperature that is collected from the bottom of a distillation column.

bottoms up

The drilling mud and cuttings that are calculated to come from the bottom of the hole to the surface after drilling new hole.

bottoms-up mud sample

Mud caught at surface after a full circulation, so it represents fluid that has been to the current bit depth and back.

bottomset beds, bottomsets

Bottomset beds are created from the lightest suspended particles that settle farthest away from an active delta front, as the river flow diminishes into a standing body of water and loses energy.

bouguer

The gravity correction for the mass of rock between the station and the reference level.

Bouguer anomaly

The gravity value left after an observation is corrected for latitude, elevation, the mass of rock between station and datum, and terrain.

Bouguer correction

The gravity correction that removes the attraction of the rock between the measurement station and the datum, using an assumed density for that slab.

Bouma sequence

The Bouma sequence is a model of sedimentary structures that helps identify underwater debris flows or turbidites. It is named after Arnold H. Bouma, who first described turbidites in 1962.

bound fluid

Pore fluid held by capillary or clay forces, which does not move under normal reservoir conditions.

bound water

An extremely thin layer of water surrounding rock surfaces or within the clay lattice or near the surface within the electrical double layer. Bound water in the pore space does not flow under normal reservoir conditions.

bound-fluid log

An NMR log recorded with a short wait time or short echo spacing so only the fast-relaxing, clay- and capillary-bound fluid is measured.

boundary condition

What is assumed at the edge of a modelled region, which often matters more than the interior detail.

boundary conditions

Boundary conditions are the flux (flow rate) or pressure states assigned to the theoretical boundaries used in developing and solving the differential equations that apply to well testing and in specifying a model to match to pressure transient data.

bounded reservoir

A reservoir with sealing outer boundaries, so production depletes its pressure instead of drawing on an effectively infinite supply.

bourdon tube

A curved flattened tube that straightens with internal pressure, the element in most mechanical gauges.

Bourdon tube pressure element

A curved, thin-walled hollow tube, closed at one end, that responds to changes in pressure by attempting to straighten out or curl up.

bow and arrow

The bow and arrow rules states that the best estimate of the direction of movement of a thrust is given by a line drawn at right angles to the chord joining the ends of the fault trace.

bow tie

The crossing, bow-shaped pattern an unmigrated section shows beneath a syncline sharp enough to focus rays, collapsed by proper migration.

bow tie analysis

A diagram putting a hazard at the center, with causes and barriers on one side and consequences on the other.

bow ties

A bow tie is a concave-upward reflection in seismic data.

bow-spring centralizer

A centralizer of curved leaf springs that flex to fit the hole and push the casing toward the middle of it.

box plots

A statistical display showing a distribution's median, quartiles and outliers in a single compact figure.

Boyle's law

An experimental gas law stating that the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature.

Boyle's Law Double Cell

A helium porosimeter method giving grain volume by expanding gas from a calibrated reference cell into a chamber holding the sample.

Boyle's Law Single Cell

A helium expansion method that measures pore volume directly, by expanding gas into the sample's pore space alone.

brachistochrone

The path of least traveltime between two points, the route a seismic ray actually follows.

bracketing

A process of elimination method in which boundaries are established around parts of a process during troubleshooting in order to loacte a problem.

bradenhead

The lowest wellhead spool, on which the casing is landed.

bragologue

A prepared, factual account of one's own achievements, used where self-advocacy does not come naturally.

braided line

Multistrand wireline used where a single-strand slickline could not carry the tension or the weight required.

braided stream

A river of shifting shallow channels carrying coarse sediment, giving sheet-like sands.

braided streams

A "braided stream" refers to a river or stream with multiple, interweaving channels that are separated by small, often temporary islands, which are called braid bars. These create a pattern resembling a braid and typically form in areas with high sediment loads and variable flow conditions where the water divides and recombines frequently.

brainstorming

Generating options without evaluating them, so judgment does not suppress ideas.

brake

A device for stopping and firmly holding the walking beam at any point in the stroke.

brake horsepower

Measurement of the actual power output of the compressor. BHP considers all the losses and inefficiencies within the compressor system. BHP reflects the effective power that the compressor provides to compress the natural gas. It considers mechanical losses, friction, heat losses, and other inefficiencies that reduce the output power of the compressor.

branch

A parallel path in a PLC ladder program. Inputs in parallel perform the logical OR function. Outputs in parallel are energized simultaneously.

branch current

The current flow through one branch of a parallel circuit.

brand

The set of associations a name carries, which determines what buyers expect.

brand awareness

The proportion of the market that recognizes the brand and knows what it does.

brand voice

The consistent tone and personality in how a brand communicates.

brazing

A welding application that heats base metals instead of melting them.

breach of contract

Failure to perform an obligation, entitling the other party to a remedy.

break

The first arrival of energy at a receiver — the first break on a shot record, or on a VSP or check-shot trace.

break circulation

To restart mud circulation after the well has stood static, overcoming the gel strength the mud has built while still.

break out

To unscrew a threaded connection — the opposite of make up.

break-even analysis

Working out that volume, and how sensitive it is to price and cost changes.

break-even point

The volume at which revenue exactly covers total cost.

breakdown pressure

The pressure at which an exposed formation fractures and begins to take fluid.

breakdown region

The range of reverse bias voltage on a voltage-current graph beyond the breakdown voltage, where a small change in voltage results in a large increase in current flow across a P-N junction without causing damage to the junction.

breakdown voltage

The critical value of reverse bias voltage required to overcome the resistance of the depletion region of a reverse-biased P-N junction, after which current flow rapidly increases.

breaker

A chemical that cuts the viscosity of a treatment fluid by cleaving its long-chain polymers, so the fluid can be produced back.

breaker contact

The contact a circuit breaker opens to interrupt current, and where arc damage shows.

breaker failure relay

A relay that detects a breaker's failure to operate and then opens other breakers to isolate a fault.

breaker trip

A circuit breaker opening on a protective signal.

breakeven price

The price at which a project just earns its required return.

breakout cathead

The drawworks-driven cathead that pulls the tongs to break out a connection.

breakout tongs

The tongs applied to loosen a made-up connection, working against backup tongs on the joint below.

breakouts

Borehole breakouts are increases in the borehole wall diameter that are parallel to the minimum horizontal stress and appear where stresses around the wellbore exceed the compressive strength of the rock.

breakover voltage

The voltage at which a solid-state device switches into conduction.

breakthrough

A situation in which a contaminated gas stream breaks through the saturated carbon bed of a carbon adsorption system without any further removal of contaminants.

breathing

The flow of air, gases, and vapors into and out of storage tanks in response to increases and decreases In ambient temperatures.

breathing apparatus

Equipment supplying air to the wearer independently of the surrounding atmosphere.

breccia

Breccia is a clastic sedimentary rock composed of angular, sharp-edged rock fragments (clasts) that are larger than 2 mm in diameter. The clasts are embedded in a fine-grained matrix, which is usually cemented together by minerals like quartz, calcite, or clay.

Brent CFD (Contract for Difference)

A short-dated swap between Dated Brent and forward Brent, used to manage timing exposure.

brent complex

The interlocking set of physical, forward, futures and swap markets around North Sea Brent.

brent crude

The North Sea blend whose price is the principal international crude benchmark.

brent price

The quoted price of the North Sea benchmark crude.

bribery

Offering or accepting something of value to influence a decision improperly.

bridge

The part of an overhead-type crane that travels on elevated rails and supports the trolley and hoist mechanism.

BRIDGE framework

A structured approach to building inclusive practice step by step.

bridge plate

A piece of metal that is used to bridge the gap between a loading dock and a truck, van, or railroad car. Also called a dock board.

bridge plug

A downhole tool set in the casing to seal it and isolate everything below.

bridge rectifier

A device or circuit that conducts during both halves of an AC cycle and produces twice the voltage of a full-wave rectifier.

bridge, router, hub, repeater, switch

The devices connecting network segments, differing in how selectively they forward traffic.

bridge-off

The build-up of sand, fill or scale in a wellbore until it blocks flow or stops tools passing.

bridging material

Graded solids added to a fluid to bridge across pore throats or fractures and seal them.

bridle

A flexible steel cable looped over the horsehead and fastened to the carrier bar.

Briggs color cube

A color scheme mapping three variables onto the red, green and blue axes of a cube, so a single color encodes all three.

bright spot

A bright spot is a seismic amplitude anomaly, or a high amplitude, that can indicate the presence of hydrocarbons. Bright spots result from large changes in acoustic impedance and tuning effect, such as when a gas sand underlies a shale, but they can also be caused by phenomena other than the presence of hydrocarbons, such as a change in lithology. This term is often used synonymously with hydrocarbon indicator.

brine

Water strongly impregnated with or containing large amounts of salt, especially sodium chloride.

bring in the well

To start the well flowing at the end of a completion or workover by lightening the fluid column or opening it up.

British thermal unit

A measurement of the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit at atmospheric pressure.

British thermal unit (BTU)

The heat required to raise the temperature of a one-pound mass of water by one degree Fahrenheit.

brittle

Brittleness is characterized by rocks that slide, fracture or rotate during movement.

broach

A downhole tool run to cut and restore the internal diameter of tubing where it has been dented or slightly collapsed.

broadside array

An electromagnetic tool arrangement with the transmitter and receiver dipoles perpendicular to the tool axis.

bromide

A dense brine salt used to make heavy completion fluids without solids.

bromide brine

A clear completion fluid made from sodium, calcium or zinc bromide, reaching densities well beyond chloride brines.

bromocresol green

A pH indicator used in place of methyl orange for alkalinity titration, green above pH 4.3 and yellow below.

Brookfield viscometer

A rotational viscometer measuring viscosity at very low shear rates, below the range of a rig viscometer.

brown hydrogen

Hydrogen from gasified coal with carbon dioxide vented, the most carbon-intensive route on the color scale.

brownfield project

Work that extends or modifies a facility already in operation.

Brownian motion

The erratic random movement of microscopic particles in a fluid, as a result of continuous bombardment from molecules of the surrounding medium.

browser

A PC program that searches a network for a node with which it can communicate. RSLinx is Allen-Bradley's network browser.

browser and plug-in compatibility

Whether course content actually runs on the software learners have.

brush holder

The part of a DC motor that holds the brush and brush tensioning assembly and provides the connection point between the brush and the field coil(s).

brush pigtail

The connecting link between a OC motor brush and a brush holder.

brush rigging

The part of a DC motor that supports the brush holders.

brush tensioning device

The part of a DC motor that holds the brush against the commutator.

brushes

The parts of a DC motor that make sliding electrical connections between the commutator and the power source.

brushless exciter

An exciter that does not have brushes or slip rings, using a rectifier instead to convert AC into DC for purposes of AC generator excitation.

brute stack

A first-pass stack made with only cursory velocity analysis, produced to see the section early.

BS&W

Basic Sediment and Water.

BS&W monitor

A device on the LACT unit which monitors the signal from the BS&W probe to determine BS&W content.

BS&W probe

An inline device which senses the BS&W content of the oil.

bsee

The United States Bureau of Safety and Environmental Enforcement, which regulates offshore operations.

BTU

British Thermal Unit; the amount of heat needed to raise the temperature of one pound of water by one degree Fahrenheit.

bubble caps

Slotted metal caps bolted over elevated nozzles or openings in contactor trays, which cause gas to break up into small bubbles for intimate contact with the glycol.

bubble count

The number of times a local probe registers a change of fluid phase, counted from its voltage oscillations across a threshold.

bubble effect

The train of secondary pulses an airgun produces as its gas bubble oscillates after the initial burst.

bubble flow

A two-phase flow regime with gas dispersed as discrete bubbles through a continuous liquid phase.

bubble point

The pressure and temperature conditions at which the first bubble of gas comes out of solution in oil.

bubble point pressure

The bubble point pressure is the pressure at which gas bubbles first come out of the solution.

bubble-tight shutoff

A valve seal tight enough that no gas passes it, verified by seeing no bubbles when the downstream side is under water.

bubbler

A level device measuring the pressure needed to bubble gas from a submerged tube.

bubbler system

An indirect level measurement system that measures the level in a tank based on the air pressure needed to force all of the liquid from a vertically mounted pipe.

bucking coil

An auxiliary coil in an induction tool wound to cancel the direct coupling between transmitter and receiver.

bucking current

The current sent through a laterolog's guard electrodes to force the survey current out into the formation instead of up the borehole.

buckling

Sideways collapse of a slender member under axial load, the failure mode of rods and tubing in compression.

buddy system

A system of organizing employees into work groups in such a manner that each member of the group is designated to be observed by at least one other member of the group. The purpose of the buddy system is to provide rapid assistance to employees in an emergency.

budget variance

The difference between budget and actual, analyzed to find the cause.

budgeting and saving

Planning personal spending so that some income is retained.

buffalo head

The flow cross on top of a frac tree into which the treating iron connects and the treatment enters the well.

buffer

In fiber optics, a plastic outer jacket coating around each fiber used to help protect the fiber from damage. In electronics, a voltage follower used to isolate one circuit from another.

buffer solution

A solution that tends to remain at a constant pH; used to calibrate certain types of analyzers, such as pH analyzers.

buffered mud

A mud whose pH resists change because it contains a weak acid and its salt together.

buffered solution

A solution of known, stable pH used to calibrate a pH meter.

buggy vibro

A vibrator source mounted on a wide-tyred buggy so it can work over soft or rough ground.

buildup test

A test in which a producing well is shut in and its bottomhole pressure recorded as it recovers.

bulk density

Bulk density is a property of solids, defined as the mass of many particles of the material divided by the total volume they occupy.

bulk modulus

A material's resistance to volume change under hydrostatic pressure — the ratio of pressure change to the fractional change in volume.

bulk packaging

Vehicle or freight containers used to ship hazardous materials with no intermediate form of containment, such as rail tank cars and tank trucks.

bulk relaxation

In an NMR measurement, the loss of coherence by hydrogen nuclei interacting with each other in the body of a fluid, away from any pore surface.

bulk volume

The total volume a material occupies, including the pore or inter-particle space within it.

bull plug

A solid plug closing off the end of a pipe run or a tubular.

bullet

A horizontal, cylindrical tank with rounded ends, supported on saddles that raise it off the ground. A type of high-pressure above ground storage tank.

bullet perforating

An early perforating method firing hardened steel projectiles from a downhole gun to punch through casing and cement.

bullhead

To pump fluid forcibly down the well and into the formation without returns, usually to push an influx back where it came from.

bullying

Repeated behavior that intimidates or humiliates, distinct from a single episode of rudeness.

bump the plug

The sharp pressure rise at surface when the top cement plug lands on the float collar, showing displacement is complete.

bumpless transfer

A controller feature that enables the controller to be changed from automatic mode to manual mode, and vice versa, without causing a change in the control signal to the process.

bund

The wall around a tank that contains its contents if it leaks.

bundle

Several pipelines — production, injection or gas lift — insulated and carried together as a single assembly.

bunker fuel

The fuel burned by the ship itself, a major and volatile component of voyage cost.

bunker silo

A bulk storage bay for solid fuel or material.

buoy

A floating mooring or marker, used for offshore loading.

buoyancy

The upward force exerted by a liquid on an object placed in it, equal to the weight of the displaced fluid.

buoyancy method

Measuring a core sample's bulk volume from the weight of fluid it displaces when submerged.

buoyant

Tending to rise through denser surrounding fluid, the force that drives migration.

buoyant force (buoyancy)

The characteristic of a liquid that causes it to push up on an object placed in it; characteristic that causes objects to float in liquids.

Bureau of Mines Correlation Index (BMCI)

An index of how aromatic a fraction is, calculated from gravity and boiling point.

burette

A type of graduated cylinder with a valve at the bottom; frequently used to perform titrations.

burial depth

The depth a rock has reached, which with time sets its temperature history.

burial diagenesis

Change in rock during burial, which destroys porosity by compaction and cementation and occasionally creates it.

burial history

The depth and temperature a rock has experienced through time.

buried faults

Buried faults may end abruptly in the subsurface at an erosional surface.

burn shoe

A milling shoe run on the bottom of a washover string to cut away material around a fish.

burn-over

Milling away the outside of a stuck tool or fish with a burn shoe so it can be released and recovered.

burner flame

The flame in a fired heater, whose shape and color say whether combustion is right.

burning air rate

The amount of air flow to which a catalyst is subjected for combustion.

burnout

Exhaustion, cynicism and reduced effectiveness from prolonged unmanaged work stress.

bus

In networking, a topology in which all devices connect in parallel to the same network wires. In electrical systems, a common conductor that connects a power source to several load circuits.

bushing

A fitting used to protect conductors from sharp edges at conduit entry/exit points. Also, a device that allows a conductor to penetrate an equipment enclosure while remaining electrically isolated, typically consisting of a conductor projecting through a cylindrical porcelain insulator.