Discover the IHRDC Energy Glossary_beta

Search or select a letter above to browse the glossary.

E

E-commerce metrics

The measures specific to online selling: conversion, basket value, abandonment, return rate.

A mode of learning that takes place electronically, often via the Internet. It requires students to use electronic devices such as computers, tablets and cell phones, usually their own. E-Learning allows learners to conduct sessions at a time and place of their choice and at their own pace, as long as they have access to a device and a Wi-Fi or data connection.

e-Procurement

Running sourcing and award through a controlled electronic platform rather than on paper.

E-stop

An emergency stop switch.

ear muffs

A form of hearing protection consisting of large, padded covers for the entire ear, used to protect from discomfort and hearing loss from noise.

ear plug

Hearing protection inserted in the ear canal.

ear plugs

A form of hearing protection that fits inside the ear canal to filter out noise.

early diagenesis

The chemical changes occurring soon after deposition and before deep burial.

early time transient data

The part of a pressure test recorded before radial flow is established, dominated by wellbore storage and skin.

earned value analysis (EVA)

Measuring progress by the value of work completed rather than by cost spent or time elapsed.

earth crust

The outermost solid layer, in which all sedimentary basins sit.

earth ground

A conductor that wilt dissipate large electrical currents into the earth.

earthquake

The sudden release of accumulated stress in the Earth as slip on a fault, radiating elastic waves.

easy to disperse

Said of a cement whose rheology responds strongly to small doses of dispersant.

easy to disperse in salt

Said of a cement that responds strongly to dispersant even when mixed on salt water.

eccentering

Eccentering is the position or movement of logging tools away from the more usual position in the center of the borehole.

eccentralizer

A device that pushes a logging tool against one side of the borehole rather than centring it.

eccentralizer, eccentralized

A device or hardware used to position equipment adjacent to the formation, away from the center of the borehole, so that it runs eccentralized.

eccentric

Off-center — as when a pipe does not sit in the middle of the hole or of the pipe around it.

eccentricity

A condition that results when a rotating component, such as a turbine shaft, is bent or out of round.

ECD

Equivalent circulating density: the effective mud density a formation sees while circulating, including the annular friction pressure above that point.

echo spacing

The interval between successive spin echoes in an NMR measurement.

economic feasibility

Whether a project can be made to pay, assessed before commitment rather than after.

economic viability

Whether a project earns its cost of capital, as distinct from whether it works technically.

economically producible

A resource that generates revenue that exceeds, or is reasonably expected to exceed, the costs of the operation.

economizer

A component that transfers heat from combustion gases leaving a boiler to feedwater flowing into the boiler, preheating the water before it enters.

eddy current

A current induced to circulate within a conductor by a changing magnetic field.

eddy current measurement

A casing inspection technique reading how pits and holes in the inner wall distort a high-frequency current induced in the steel.

edge ai

Running AI models on the equipment generating the data rather than sending the data elsewhere.

edge computing

Processing data at or near its source instead of transmitting it to a central system.

Ediacaran period

The Ediacaran is a geological period that spans 96 million years from the end of the Cryogenian Period at 635 Mya to the beginning of the Cambrian Period at 538.8 Mya.

Edison-base

The threaded base that is used on standard screw-base plug fuses.

EDTA

Ethylenediaminetetraacetic acid: a chelating agent that binds metal ions, used to sequester iron in acid treatments and to titrate hardness in water analysis.

eductor

A device using a motive jet to entrain and pump another fluid.

EEPROM

Electrically Erasable Programmable Read-Only Memory. A form of memory often used for PLC project backup.

effective (RMS) voltage

A value equal to roughly 70% of the peak voltage. Multimeters measure RMS (root mean square) voltages, while oscilloscopes measure peak or peak-to-peak voltages.

effective bits

A measure of a digital oscilloscope's ability to accurately reconstruct a signal. Because actual errors include noise and distortion, the frequency and amplitude of the signal, as well as the bandwidth of the instrument, must be specified.

effective laminar flow

Displacing mud with cement in laminar flow at a rate and rheology chosen so the cement front stays stable rather than fingering.

effective medium theory

A method of computing the bulk properties of a heterogeneous material by replacing it with a uniform medium that behaves the same way, abbreviated EMT.

effective permeability

A measure of the conductance of a porous medium for one fluid phase when the medium is saturated with more than one fluid. When a second phase is present, the permeability to each phase is referred to as its effective permeability.

effective porosity

The interconnected pore volume, or void space, in a rock that contributes to fluid flow in a reservoir. Porosity not considered effective includes water bound to clay particles and isolated vuggy porosity. Only the effective porosity contributes to hydrocarbon production.

effective shot density

The number of perforations per foot that are actually producing or injecting, as opposed to the number shot.

effective values

AC values based on the relationship that one ampere, peak value, of AC current produces the same heating effect as .707 amperes of DC current; also called RMS values.

effective velocity

A single velocity that reproduces the observed traveltime through a layered section, as the average velocity does for vertical travel.

effective voltage

In AC circuits, the voltage based on the relationship that one ampere peak value of AC current produces the same heating effect as 0.707 amperes of DC current. Also, the voltage that actually exists in a stator, combining applied voltage with opposing and aiding voltages.

effective water saturation

The fraction of the effective pore space occupied by water, excluding clay-bound water.

effective wellbore

The apparent wellbore radius after damage or stimulation is accounted for.

effective wellbore radius

The wellbore radius that would give the observed inflow performance if the skin factor were zero.

efficiency

The amount of energy expended to do work divided by the amount of energy supplied.

effluent

The liquid or process fluid that is discharged from any of the various stages of wastewater treatment or from process equipment (e.g., reactor effluent).

effort-driven scheduling

Duration derived from the work required and the resources assigned.

egoism

The view that one ought to act in one's own interest.

eigenvector

A direction in which a linear transformation acts only by scaling, its eigenvalue being the scale factor.

eight stages of the entrepreneurial process

The course's breakdown of that sequence from discovery through to harvest.

eight-bit word

A digital expression of 8 bits; for example, 0100 0111.

ejector

A device using a high-velocity jet to entrain and move another fluid, with no moving parts.

elastic

Describing a material that deforms under stress and recovers its original shape completely once the stress is removed.

elastic anisotropy

Variation of a rock's elastic properties with direction, so that stiffness and velocity depend on the angle of measurement.

elastic constants

The set of moduli — Young's, bulk, shear and Poisson's ratio among them — describing how a material deforms elastically under stress.

elastic deformation

Deformation that is fully recovered once the applied stress is removed.

elastic impedance

The offset-dependent generalization of acoustic impedance, so that inverting far-offset stacks gives a property comparable between angles.

elastic limit

The stress beyond which a material no longer returns to its original shape — the yield point.

elastic moduli

The constants relating stress to strain for an elastic material, each describing a different mode of deformation.

elastic neutron scattering

Elastic neutron scattering is where the neutron "bounces" off the nucleus without exciting or destabilizing it. The neutron loses energy with each elastic interaction.

elastic parameter

A constant relating stress to strain, and the bridge between rock property and seismic response.

elastic property

A rock property relating stress to strain, and the link between rock and seismic response.

elastic wave

Elastic wave propagation involves motion in a medium in which, when particles are displaced, a force proportional to the displacement acts on the particles to restore them to their original position.

elastic waves

An elastic wave is a motion in a medium in which, when particles are displaced, a force proportional to the displacement acts on the particles to restore them to their original position.

elasticity

The characteristic of a solid that causes it to try to return to its original shape after being deformed by stress.

elastomer

A rubber-like sealing material, whose limits set the temperature and chemical rating of equipment.

elastomer bellow

A flexible rubber element accommodating movement while sealing.

elbow

A type of fitting that is used to change the direction of a conduit run.

elective training

Depending upon client-selected system settings, users may either self-assign or request approval to take elective courses. Administrators can approve or decline requests, link users or groups of users to a course or courses, set expiration dates and modify or delete elective training linked to a user.

electric control system

A safety control system in which an unsafe condition signals the ignition system to ground, shutting off the fuel supply to the prime mover.

electric drill

A powered tool for boring holes.

electric gas lift valves

Gas lift valves whose port opening can be set remotely from surface, from fully open to shut.

electric power supply

A device, or a group of devices, that converts normal generated AC power into power that is suitable for use with electronic equipment.

electric probe

A small production logging sensor that reads the local fluid as conductive or non-conductive as it passes through it.

electric submersible pump

An artificial lift system in which a multistage centrifugal pump is driven downhole by an electric motor supplied from surface.

electric wireline

The cable carrying power and data to a logging or perforating tool.

electrical anisotropy

A difference between vertical and horizontal resistivity within a formation, at the scale the tool measures.

electrical conductivity

A material's ability to carry electrical current — the reciprocal of resistivity.

electrical coupon

A corrosion monitoring probe whose electrical resistance rises as the element loses metal, giving a continuous corrosion rate.

electrical diagram

A diagram that uses symbols to represent the components and connections of an electrical system.

electrical distribution system

A system that distributes electric power from a substation.

electrical double layer

The structured arrangement of ions in the water immediately against a charged clay surface.

electrical hazard

A hazard from electricity, whether shock, arc flash or ignition.

electrical impedance probe

A production logging probe distinguishing water from hydrocarbon by the impedance of the fluid at its tip.

electrical interlock

A circuit arrangement intended to prevent energizing an electrical device in a way that could damage it or that could be unsafe.

electrical log

Any log recorded on an electrical wireline, and historically the resistivity and SP suite specifically.

electrical permittivity

A material's capacity to store charge in an applied field, the property a dielectric log responds to.

electrical resistance probe

A corrosion probe measuring metal loss from the increase in electrical resistance of a thin exposed element.

electrical resistivity

A material's opposition to electrical current, measured in ohm-meters and independent of sample size.

electrical shock

The physical reaction of the body to current flow through it.

electrical stability test

The oil mud test in which voltage across a probe is raised until the emulsion breaks down and conducts.

electrical submersible pump

A downhole electric pump for high rates, limited by heat, gas and power cable reliability.

electrical survey

A measurement of formation electrical properties made by passing current into the rock and reading the resulting potentials.

electrically neutral

Carrying no net charge, the state a bonded conductor is held at.

electricity

The movement of electrons.

electrification

Replacing direct fuel use with electricity, moving the emissions question to the grid.

electrochemical

Involving electron transfer, the mechanism of corrosion and cathodic protection.

electrochemical analyzers

Analyzers in which the analysis is based on the interaction of electrical current with a sample material.

electrochemical device

Equipment converting between chemical and electrical energy, covering fuel cells, electrolyzers and batteries.

electrode

An electrical conductor through which electricity enters or leaves a non-metallic part of a circuit, such as a formation rock during well logging.

electrode device

A resistivity tool that passes current into the formation through metallic electrodes at low frequency, rather than inducing it.

electrode resistivity

Resistivity measured by passing current into the formation through electrodes, as in a laterolog.

electrodes

Electrodes are conductors through which electricity enters, or leaves, an object.

electrodynamic brake

A braking system in which the drawworks motor is run as a generator, dissipating the load's energy electrically.

electrofacies

Electrofacies are numerical combinations of petrophysical log responses that reflect specific physical and compositional characteristics of a rock interval; they are determined by multivariate procedures that include principal components analysis, cluster analysis, and discriminant analysis.

electrohygrometer

An instrument measuring relative humidity electrically, used in mud work to determine water activity.

electrokinetic potential

The voltage generated when an electrolyte is forced to flow through a permeable medium — the streaming potential.

electrolysis

Splitting water into hydrogen and oxygen with electricity, clean only if the electricity is.

electrolysis cell

The single electrode pair where water is split, stacked in series to reach useful capacity.

electrolyte

A substance that, when dissolved in water, forms a solution that can conduct electric current. This liquid solution is also generally referred to as an electrolyte.

electrolyte level

The liquid level in a cell, whose fall exposes the plates.

electrolyte solution

An electrolyte solution is a solution that generally contains ions, atoms or molecules that have lost or gained electrons, and is electrically conductive. For this reason they are often called ionic solutions.

electrolytic

Involving current passing through an electrolyte, which drives both plating and corrosion.

electrolytic capacitor

A type of polarized capacitor that provides more capacitance in a small space than most other types of capacitors.

electrolyzer

The unit performing electrolysis, sized in megawatts of input rather than tonnes of output.

electromagnet

A coil producing a magnetic field only while energized, the working element of relays and solenoids.

electromagnetic analyzers

Analyzers that use radiation from specific bandwidths along the electromagnetic spectrum to monitor various properties of sample materials.

electromagnetic caliper

A casing inspection measurement that infers wall thickness and internal diameter from the electromagnetic response of the pipe.

electromagnetic coupling

Transfer of electrical power from one circuit to another circuit through variations in the magnetic field.

electromagnetic drill

An electric drill used to cut metal It has an electromagnetic base that is energized to secure the drill in place against the work.

electromagnetic field

A physical field produced by electrically charged objects. It affects the behavior of charged objects in the vicinity of the field. The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction.

electromagnetic field (EMF)

A field of magnetic flux cause by electrical current passing through a conductor.

electromagnetic heating

Raising reservoir temperature by dissipating electromagnetic energy in the rock and its fluids, rather than by injecting heat.

electromagnetic induction

The process by which an electromotive force is produced within a conductor when there is relative motion between the conductor and a magnetic field. In transformers, the process by which power is transmitted from a primary winding to a secondary winding via an expanding and contracting magnetic field.

electromagnetic method

Any technique measuring natural or artificially generated electric and magnetic fields to infer subsurface conductivity.

electromagnetic methods

Electromagnetic methods are a group of techniques in which natural, or artificially generated, electric or magnetic fields are measured in boreholes in order to map the variations in the formation's electrical properties, resistivity, permeability or permittivity.

electromagnetic propagation

Logging that measures the phase shift and attenuation of an electromagnetic wave travelling through the formation.

electromagnetic propagation logging tools

Electromagnetic propagation logging tools measure the properties of electromagnetic waves as they move through a formation. Propagation resistivity logs work between about 100 kHz and 10 MHz. Dielectric propagation logs work between 20 and 200 MHz. Logs made above 200 MHz and into the GHz range are known as electromagnetic propagation logs.

electromagnetic propagation measurement

A high-frequency, around 1 GHz, measurement of the formation's dielectric properties from a pad-mounted antenna.

electromagnetic radiation

Electrical and/or magnetic energy moving through space.

electromagnetic spectrum

The range of different types of electromagnetic radiation.

electromagnetic switch

A device that uses electromagnets to open or close a circuit.

electromagnetic thickness

A measurement of casing or tubing wall thickness inferred from the electromagnetic response of the steel.

electromagnetic wave

Electromagnetic waves (EM) are waves that are created as a result of vibrations between an electric field and a magnetic field.

electromagnetism

Magnetism that is created by current flowing through a conductor.

electromotive

Concerning the force driving current round a circuit.

electromotive force

An electromotive force is a difference in potential that tends to give rise to an electric current.

electron

A negatively charged particle that orbits around the nucleus of an atom.

electron flow

The movement of electrons, opposite in direction to conventional current.

electronic flow measurement

Flow computed by an electronic device from live pressure, temperature and differential, replacing the chart recorder.

electrons

The electron is a subatomic particle carrying a negative electric charge. It has no known components or substructure. Therefore, the electron is generally believed to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton.

electrostatic

Concerning stationary electric charge, which accumulates on flowing non-conductive liquid and ignites vapor.

electrostatic discharge

The sudden release of accumulated charge, which can ignite vapor or destroy electronics.

electrostatic field

The field round accumulated charge.

electrostatic material

Charged materials also have an electrostatic field and lines of force associated with them.

electrostatic precipitator

An emission control device that uses plates, wires, and an electrostatic field to remove contaminants or catalyst particles from a gas or flue gas stream before it is released to the atmosphere.

elemental capture spectroscopy

A log measuring the energy spectrum of capture gamma rays to give the concentrations of silicon, calcium, iron, sulfur and other elements.

elements of compensation

Base pay, variable pay, benefits and non-financial reward taken together.

elevation correction

A time correction bringing seismic sources and receivers to a common datum plane, removing the effect of their elevation.

elevation drawing

A side view of a building or diagram showing the locations of major pieces of equipment relative to a certain elevation, usually sea level, showing height but no interior detail.

elevator

An elevator is a hinged mechanism that may be closed around drill pipe, or other drill string components, to facilitate either lowering them into the wellbore or lifting them out of the wellbore.

elevator, elevators

An elevator is a hinged mechanism that may be closed around drill pipe, or other drill string components, to facilitate either lowering them into the wellbore or lifting them out of the wellbore.

eliminate swirl

Removing rotation from an entering stream so it does not disturb the liquid surface.

eliminator

Internal device removing entrained droplets from a gas stream before it leaves a vessel.

ellipse

The shape of the drainage area around a well in an anisotropic reservoir.

ellipsoid

The three-dimensional shape describing anisotropic permeability or the earth's figure.

email etiquette

The conventions that keep email efficient and prevent avoidable offense.

email marketing

Marketing by direct email to a permissioned list.

embayments

Embayments are extensions of the sea into a recess or indentation of a coast.

embedded systems

Computers built into equipment, often long-lived and rarely patched.

embedded wavelet

The wavelet actually present in recorded seismic data, which has to be estimated before the data can be inverted or tied to a well.

embedding

A representation of data as a vector of numbers, so that similarity between items becomes distance in that space.

embrittlement

The loss of a metal's ductility and tensile strength, so that it fractures rather than deforming under load.

embry

A stratigrapher whose sequence stratigraphic terminology is widely used.

emergency

Any occurrence, such as equipment failure, rupture of containers, or failure of control equipment, that results or could result in an uncontrolled release of a hazardous substance or endangerment of personnel.

emergency preparedness and response

The plans, equipment and drills that determine how well an incident is handled.

emergency response

A response effort by employees from outside the immediate release area or by other designated responders (e.g., mutual aid groups, local fire departments) to an occurrence that results, or is likely to result, in an uncontrolled release of a hazardous substance.

emergency response command structure

The defined chain of authority during an incident, so decisions are made by known people.

emergency shutdown

An unplanned or unscheduled furnace shutdown; a situation in which a furnace is shut down immediately to reduce the risks of danger and damage.

emergency shutdown valve (ESDV)

A fail-safe valve that isolates a process section automatically when the emergency shutdown system is triggered, abbreviated ESDV.

emergent behavior

Capability that appears in a large model without having been trained for specifically, and is absent in smaller versions of the same model.

EMI cable

Electromagnetic Interference Cable. An electrical cable used between a variable speed controller and its motor designed to reduce electromagnetic interference.

emission reduction

A measured fall in released greenhouse gas against a stated baseline.

emissions

Substances that are discharged into the air.

emissions reduction target

A stated commitment to cut emissions by a set amount against a base year.

emitter

One element of a transistor. In a bi-polar transistor, the emitter is one of the poles.

emotional intelligence

Recognizing and managing emotion, in oneself and others, as a working skill.

empirical

Derived from observation and data rather than from theory.

employee

An individual employed in a laboratory workplace who may be exposed to hazardous chemicals in the course of his or her assignments.

employee assessment (EA)

See, Self-Assessment.

Employee Assistance Program (EAP)

Confidential counseling and support provided by the employer.

employee buy-in

Genuine acceptance of a change by the people who must work differently.

employee classification

Determining whether a worker is an employee or a contractor, with different rights and taxes.

employee engagement

The discretionary effort people give beyond what the job strictly requires.

employee experience measurement

Assessing what working at the organization is actually like, beyond engagement scores.

employee life cycle

The stages from attraction and hiring through development to exit.

employee privacy and confidentiality

The limits on what an employer may hold, see and disclose about an employee.

employee rights

The entitlements an employee holds by statute, contract or policy.

employee selection

Choosing among assessed candidates, and defending the choice if challenged.

employee statement [evidence]

As part of knowledge evidence, an employee may provide a personal statement how they would respond to a situation that might arise, describing the process, procedure and/or response to a situation. The Assessor would confirm the content of the statement by questioning the employee further.

employee well-being

The overall physical, mental and social health of the workforce.

employer branding

The reputation that determines who applies before any vacancy is advertised.

employer tax duties

The employer's obligations to withhold and remit payroll taxes.

employer-sponsored volunteerism

Paid time for employees to work on community causes.

employment at will (EAW)

The United States default that either party may end employment at any time for any lawful reason.

empowered team

A team holding the authority to decide how it does its work.

empowerment

Giving people the authority and confidence to act without seeking permission each time.

emulsification

The dispersal of one liquid as droplets in another.

emulsified

Dispersed as droplets in another liquid rather than separated from it.

emulsified asphalt

A type of liquid asphalt produced by mixing straight-run asphalt and chemically-treated water.

emulsified oil

Oil holding dispersed water that will not settle out.

emulsifier

A surfactant that lowers interfacial tension between two immiscible liquids so one disperses as stable droplets in the other.

emulsifying

Causing oil and water to disperse in one another rather than separate.

emulsifying agent

The substance which determines the stability of an emulsion by forming a film around the suspended droplets.

emulsifying agents

Substances which hold emulsions together, such as asphalt, paraf¬fins, some minerals, etc.

emulsion

A mixture of two liquids that do not normally mix (such as oil and water), held together by emulsifying agents. The general name given to the mixture of fluids in a well stream.

emulsion flow

A flow regime in which water travels as fine droplets dispersed through a continuous oil phase rather than as a separate stream.

emulsion mud

A water-base mud carrying dispersed oil or synthetic hydrocarbon as its internal phase.

emulsion stability

Measured by the degree of difficulty in breaking the emulsion; affected by several factors.

emulsion treater

Vessel applying heat, and often chemical, to break an emulsion into clean oil and water.

EN

The mnemonic for the "Enable" bit in many common functions. The rung remains true while the instruction is executing.

en echelon

Describing a set of closely spaced, parallel or overlapping structures arranged in a stepped pattern.

en échelon faults

En échelon faults are characterized by an approximately parallel formation at an oblique angle to a particular direction.

encoder

A feedback device typically used with a variable speed controller to monitor the position and speed of a shaft by generating pulses as the shaft turns.

encoder resolver

The device converting shaft position into an electrical signal.

encroachment

Water advancing into the reservoir from the aquifer as pressure falls.

encryption

Transforming data so it is unreadable without the key.

end grinder

A medium-sized portable power grinder with a shaft that runs parallel to the axis of the tool casing. The grinding wheel or other attachment is located at one end of the grinder. Also called a pencil grinder or a horizontal grinder.

end point

The point in a titration at which the reaction is complete and reagent addition stops, marked by an indicator change.

end-on

End-on is an acquisition method of reflection surveying in which the source point is at the end of the geophone spread.

endcap

The cap closing the end of a housing or element.

endfire array

An electromagnetic tool arrangement with transmitter and receiver dipoles aligned along the tool axis.

endless sling

A continuous loop of wire rope or synthetic material sometimes called a grommet sling.

endless tubing

Coiled tubing — a continuous string with no connections, spooled on a reel.

endothermic

Absorbing heat, so the reaction stops unless heat is supplied.

endothermic reaction

A reaction that absorbs or requires heat to keep going.

endothermic reactions

Chemical reactions that absorb heat.

endplay

The permitted axial movement of a shaft in its bearings.

ene

A suffix for the name of a hydrocarbon whose carbon atoms are linked together by at least one double bond.

energize

Apply power to a circuit or device.

energized

The state of a conducting device, or material, that is electrically connected to a source of electric current.

energized equipment

Equipment with power applied, which must be treated as live until proved otherwise.

energy

The ability or capacity for doing work, existing in several forms that can be converted from one to another. Electrical energy is usually measured in kilowatt-hours, while heat energy is usually measured in British thermal units.

energy control program

A program that helps ensure that machinery is not energized and is inoperative while it is being serviced or maintained.

energy intensive

Consuming a large amount of energy per unit of output, which is what makes electrolysis cost-sensitive.

energy mix

The proportions in which each fuel and technology meets a country's energy demand.

energy security

A country's ability to obtain reliable energy at tolerable cost and political risk.

energy source

A component that provides the energy necessary for a system to perform its task.

energy submarkets

The distinct end uses — power, transport, heat, feedstock — that compete for energy supply.

energy transition

The shift of the energy system away from unabated fossil fuels toward lower-carbon sources.

enertech (organizational design case)

The organizational design case used in the talent and workforce programs.

enforceability

Whether a court or tribunal will actually compel performance of an obligation.

engine hour meter

An instrument on a forklift's dashboard that records the total number of hours the engine has been in operation.

engineering controls

Controls (e.g., sharps disposal containers, self-sheathing needles) that isolate or remove the bloodborne pathogens hazard from the workplace.

engineering procurement

The first two stages of an engineering, procurement and construction contract.

engineering units

The physical measurement units in which process measurements are calculated and displayed, such as psi, cubic meters per hour, inches of water, or gallons per minute.

English system

The system of linear measurement that includes yards, feet, and inches.

engulfment

The surrounding and effective capture of a person by a liquid or finely divided (flowable) solid substance that can be aspirated to cause death by filling or plugging the respiratory system or that can exert enough force on the body to cause death by strangulation, constriction, or crushing.

enhanced diffusion

An NMR acquisition using deliberately long echo spacing, so that diffusion separates fluids of different viscosity in the T2 distribution.

enhanced hydrocarbon recovery

Enhanced hydrocarbon recovery, sometimes termed tertiary recovery, is the extraction of hydrocarbons from a producing field which cannot be recovery otherwise.

enhanced oil recovery

Enhanced oil recovery (EOR), or tertiary recovery, is a process for extracting oil that has not already been retrieved through the primary or secondary oil recovery techniques.

enhanced oil recovery (EOR)

One or more methods applied to an underground reservoir after the primary production phase to improve recovery of hydrocarbons and make it more productive or productive again.

enhanced recovery

Techniques recovering oil that pressure maintenance and waterflood leave behind.

enhanced recovery method

A technique recovering oil beyond what pressure maintenance achieves.

enhancement type MOSFET

A type of MOSFET that does not have a channel between the source and drain. Current flow is controlled by the capacitance effect between the gate and the substrate. The enhancement type MOSFET will only conduct when the gate potential is opposite to the polarity of the source.

entrained

Carried along within a flowing stream, as gas bubbles in liquid.

entrained amine

Amine carried out of the contactor with the gas, a loss and a downstream fouling risk.

entrained droplet

A droplet carried along by gas fast enough to keep it suspended.

entrained gas

Gas dissolved in the well-stream liquids.

entrained liquid

Liquid carried along by gas rather than settling out.

entrainment

Liquid or solid being carried along by a faster-moving stream instead of separating out.

entrance hole

The hole a perforating charge makes in the inner wall of the casing, where the jet enters.

ENTRANS (energy transition simulation)

The energy transition simulation, planning a supply mix to 2050.

entrapment

The accumulation and retention of hydrocarbons in a trap.

entrepreneurial process

The sequence from spotting an opportunity to building an operating business.

entrepreneurship

Creating and building a venture, accepting the risk in exchange for the return.

entropy

Entropy is a lack of order or predictability; gradual decline into disorder.

entry

The action by which a person passes through an opening into a permit-required confined space. Entry includes ensuing work activities in that space and is considered to have occurred as soon as any part of the entrant's body breaks the plane of an opening into the space.

entry permit (permit)

The written or printed document that is provided by the employer to allow and control entry into a permit space and that contains the information specified in paragraph (f) of the OSHA Permit Required Confined Space Standard.

entry supervisor

The person (such as the employer, foreman, or crew chief) responsible for determining if acceptable entry conditions are present at a permit space where entry is planned, for authorizing entry and overseeing entry operations, and for terminating entry.

envelope

In oscilloscopy, the outline of a signal's highest and lowest points acquired over many repetitions. In electronics, the circle drawn around a transistor symbol to indicate a discrete component.

Environmental and Social Impact Assessment (ESIA)

The same assessment widened to cover effects on communities and livelihoods.

environmental assessment

A study that can be required to assess the potential direct, indirect and cumulative environmental impacts of a project.

environmental corrections

Adjustments applied to a log to remove the effects of borehole size, mud, temperature and pressure, returning the reading to standard conditions.

environmental forces

Change pressures originating outside the organization.

environmental hazard

A condition able to harm the environment.

Environmental Impact Statement (EIS)

The formal assessment of a project's environmental effects required before approval.

eolian

Eolian, or aeolian, is an environment arising from wind action. Examples of this are deserts, sand dunes, beaches, glacial outwash and agricultural fields.

EOR

Enhanced oil recovery: methods that recover oil left after primary and secondary production by altering the properties of the oil or the forces trapping it.

EPA

The Environmental Protection Agency, the US federal body that writes and enforces environmental regulation, including the air-quality standards industry must meet.

Epanechnikov kernel

A parabolic weighting function used in kernel density estimation, zero beyond a fixed bandwidth.

EPC contract (Engineering, Procurement and Construction)

A contract under which one contractor takes design, procurement and construction to a completed facility.

EPC contractor

The firm carrying single-point responsibility for engineering, procurement and construction.

epicondylitis

Inflammation of the tendons located at the elbow that control wrist movements. Depending on which tendon is involved, it is referred to as tennis elbow or golfers elbow.

epithermal

Formed at shallow depth and moderate temperature by circulating hot water.

epithermal neutron

A neutron slowed but not yet thermal, whose detection reduces the effect of formation salinity.

epithermal neutron porosity measurement

A measurement based on the slowing down of neutrons between a source and one or more detectors that measure neutrons at the epithermal level (between approximately 0.4 and 10 eV). The slowing down process is dominated by hydrogen. By measuring neutrons at the epithermal rather than thermal level, the response is a purer estimate of hydrogen index, unaffected by thermal absorbers.

epithermal neutrons

Epithermal neutrons (0.025 eV; 0.4 eV) are neutrons of kinetic energy greater than thermal.

epm

Equivalents per million: a concentration unit expressing ionic content in terms of chemical combining power rather than mass.

epsilon (ε)

Thomsen's parameter for the fractional difference between horizontal and vertical P-wave velocity in a VTI medium.

equal employment opportunity (EEO)

The principle that employment decisions must not rest on protected characteristics.

Equal Employment Opportunity Commission (EEOC)

The United States agency enforcing federal anti-discrimination employment law.

equal pay policy

The stated commitment and method by which pay equity is maintained.

equal spread method

A type of parallel offset in which the side-by-side pipes remain a constant distance apart before, during, and after the offset.

equal-pressure torch

A type of torch in which oxygen and acetylene are mixed in a mixing chamber inside the torch body.

equalized breathing

A breathing technique used to steady the voice and settle nerves before speaking.

equalizer

The cross bar connecting the pitman arms to the walking beam.

equalizer bearing

The pivot point between the equalizer and the walking beam. This can be either a journal bearing or a roller bearing.

equalizer plate

A rigging connector that has three or more holes and is commonly used to level loads when the sling legs are of unequal length.

equalizing line

Line connecting two spaces so pressure cannot differ across a component.

equalizing loop

The valved piping around a snubbing unit's stripping rams that lets pressure be balanced across them before they are opened.

equalizing valve

A valve opened to bring pressure to the same level on both sides of an isolation barrier before it is moved.

equation

A statement showing that the mathematical expressions on each side of an equal sign are equivalent.

equation of state

A relationship giving a fluid's density, or volume, as a function of pressure, temperature and composition.

equation state

The relation tying pressure, volume and temperature for a fluid, from which phase behavior follows.

equilateral triangle

A triangle that has three equal sides and three equal angles.

equilibrium

A state of balance.

equilibrium (static) state

The state of a body at rest; the conditions that exist in a transistor when no biasing potential is applied.

equilibrium reaction

A reversible reaction; a reaction in which reactants form products and products revert back into reactants.

equipment arrangement diagram

A drawing showing the exact location of major equipment in a system; often referred to as a floor plan.

equipment grounding

Bonding equipment to earth so a fault current has a path and the frame cannot rise in voltage.

equipment location index

A reference that typically lists, identifies, and gives the location of equipment.

equipment malfunction

Equipment failing to perform as intended.

equipotential

Equipotential is a surface or line composed of points all at the same potential. In this context, height or elevation.

equipotential method

Mapping the potential field set up by fixed current electrodes, by walking a measuring electrode over the survey area.

equity

Adjusting for different starting points so that opportunity is genuinely equal.

equity owner

A party holding an ownership stake in the venture rather than a purely contractual entitlement.

equity statement

The statement showing how shareholders' equity changed over the period and why.

equivalent circulating density

The effective density exerted by a circulating fluid against the formation that takes into account the pressure drop in the annulus above the point being considered.

equivalent conductance

The conductivity a brine provides per unit concentration of a given ion, so that different ions can be compared on the same basis.

equivalent fractions

Fractions that have the same value but are expressed with different numerators and different denominators.

equivalent sack

The mass of a blended cementitious material that occupies the same absolute volume as one sack of neat cement.

equivalent water resistivity

The effective resistivity a water would need to produce the observed electrochemical potential, symbol Rwe.

equivalent weight

An element's or compound's molecular weight divided by its valence — the mass that supplies one unit of combining power.

ERD

Extended-reach drilling: wells whose horizontal displacement is several times their vertical depth, demanding specialized planning, torque-and-drag control and hole cleaning.

ergonomic risk factors

Factors that when severe enough, or after a long enough period to time, either alone but especially in combination, can result in an MSD. Ergonomic risk factors include awkward postures, force, repetition, static postures, contact stress vibration, and cold temperatures.

ergonomics

The science of fitting jobs to people. Ergonomics, which encompasses knowledge about physical abilities, limitations and other human characteristics, is used to prevent MSDs.

erode

To wear away and remove rock by physical, chemical or biological action, and to transport the debris.

erosion

The wearing away and removal of material by moving fluid, ice or chemical attack.

erosion corrosion

Accelerated metal loss where flow strips away the protective corrosion product film as fast as it forms.

erosional

Formed by removal of material rather than by deposition.

erosional surface

A surface where rock was removed before deposition resumed, and a common trap boundary.

error

The difference between the set point and the value of a process variable (also called deviation). In variable speed controllers, the difference between the command signal and the feedback signal.

error typology

The classification of errors — slips, lapses, mistakes, violations — since each needs a different remedy.

ES test

The electrical stability test, which raises voltage across a probe in an oil mud until the emulsion conducts.

escape line

An inclined cable from the derrick monkeyboard to a ground anchor, allowing the derrickman to slide clear in an emergency.

escravos terminal

The Niger Delta export terminal and gas processing complex.

ESD

Electrostatic discharge (ESD) is the sudden and momentary electric current that flows between two objects at different electrical potentials. The term is usually used in the electronics and other industries to describe momentary unwanted currents that may cause damage to electronic equipment.

ESDS

Another cause of ESD damage is through electrostatic induction that is later discharged to an ESD sensitive device, or ESDS. This occurs when an electrically charged object is placed near a conductive object isolated from ground. The presence of the charged object creates an electrostatic field that causes electrical charges on the surface of the other object to redistribute. Even though the net electrostatic charge of the object has not changed, it now has regions of excess positive and negative charges.

ESG (Environmental, Social and Governance)

The environmental, social and governance factors investors weigh alongside financial performance.

ESG reporting

Disclosing performance on those factors, increasingly against a defined standard.

ESP

Electrical submersible pump: a multistage centrifugal pump run on the end of the tubing and driven by a downhole electric motor.

ESPO blend

The crude exported through the East Siberia–Pacific Ocean pipeline to Asian markets.

essential vs. nonessential industry

The distinction used to decide which operations continue during an emergency or shutdown.

estimated ultimate recovery (EUR)

The sum of reserves remaining as of a given date and cumulative production as of that date.

estuarine

Pertaining to an estuary — the semi-enclosed coastal setting where a river mouth meets the sea.

estuary

A semi-enclosed coastal body of water where a river's fresh water mixes with sea water.

eta (η)

The anellipticity parameter combining Thomsen's epsilon and delta, which controls non-hyperbolic moveout at long offsets.

eth

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

ethane

A colorless, odorless, light gaseous hydrocarbon (C2H6) belonging to the paraffin series. Used especially to make ethylene, the first step in making plastics.

ethane propane

The mixed natural gas liquid stream sold as a combined product.

ethane propane butane

The successive natural gas liquids recovered in fractionation.

ethanol production

Making ethanol for fuel blending, largely from crops.

Ethernet

A communications protocol used to allow the implementation of large local area and wide area networks.

ethical culture

An environment where doing the right thing is expected and supported.

ethical decision-making model

A defined sequence for working through an ethical problem rather than reacting to it.

ethical framework

A structured basis for reasoning about what is right in a given case.

ethical lapse

A failure of conduct, usually incremental rather than a single decision to do wrong.

ethical leadership

Setting the standard of conduct by what the leader does, not what they say.

ethical procurement

Sourcing that resists corruption, conflict of interest and exploitation in the supply chain.

ethical relativism

The view that moral standards are valid only relative to a culture or individual.

ethical sourcing

Buying in a way that avoids exploitation, corruption and unsafe conditions upstream.

Ethical Triangle

The framework weighing principles, consequences and virtue together in a decision.

ethics training

Instruction intended to make people recognize and handle ethical problems.

ethics vs. compliance

Doing what is right against doing what is required, which do not always coincide.

ethylene

The most widely produced olefin, and the base of polyethylene.

ethylene glycol

A liquid used to inhibit hydrate formation and to dehydrate gas.

ethylene propylene

The two principal olefins produced by steam cracking.

etiologic

Of or relating to the branch of medical science concerned with the causes and origins of diseases; the term “etiologic agent” is synonymous with “infectious substance.”

Euclidean dimension

One of the mutually perpendicular directions of ordinary space, taken as X, Y and Z.

Euclidean distance

Straight-line distance between two points, the square root of the summed squared coordinate differences.

European community (EC)

European countries that have formed a single trading bloc.

eustasy

Change in global sea level, driven by the volume of water in the oceans or by the volume of the ocean basins themselves.

eustatic

Pertaining to global sea level and its changes, as opposed to local relative sea level.

eustatic sea

Global sea level, whose changes drive stratigraphic cycles.

eustatic sea level

Global sea level, set by the volume of ocean water and by the volume of the ocean basins holding it.

euxinic

Euxinic refers to a condition of water where there is a lack of oxygen (anoxia) and a high level of hydrogen sulfide. This is often found in stagnant, deep water bodies like the Black Sea and certain fjords.

evacuated cylinder

A sample cylinder which has had the air removed from it by use of a vacuum pump.

evacuation procedure

The written method for clearing people from an area.

evaporate

To change from a liquid state to a gaseous or vapor state.

evaporation

The process by which a liquid changes to a gas or vapor state; the conversion of water droplets to water vapor.

evaporation pit

A lined surface pit in which produced brine or waste fluid is left to evaporate.

evaporator

The component in a refrigeration system that removes heat from a heat source. Also, an auxiliary vessel that uses heat transfer to vaporize and remove a portion of a liquid stream from a process unit.

evaporite

An evaporite is a water-soluble mineral sediment that results from concentration and crystallization by evaporation from an aqueous solution.

evaporite, evaporitic

An evaporite is a water-soluble mineral sediment that results from concentration and crystallization by evaporation from an aqueous solution.

evaporitic

Pertaining to evaporites — minerals and rocks precipitated as a body of water evaporates.

evening tour

The drilling crew shift beginning in the late afternoon.

event

A coherent arrival in seismic data — a reflection, refraction or diffraction — produced by energy returning from the subsurface.

Exam Content Outline

The published breakdown of what an exam covers and in what proportion.

examples

Information included in Chapter 9 of the NEC to demonstrate how to perform load calculations for various types of buildings, feeders, and branch circuits.

excavation effect

The excavation effect is that part of the effect of gas on the neutron porosity measurement that is not explained by differences in the hydrogen index. By using the concept of hydrogen index, the only significant contributor to the neutron porosity in a gas zone is the liquid-filled porosity, since the hydrogen indices of gas and matrix are close to zero. However, the resultant liquid-filled porosity is found to be too low. The error comes from treating the gas-filled porosity as matrix. If this matrix is excavated and replaced with gas, the correct response can be predicted.

excelsior

Sometimes called "hay" and is used for filtering oil and water emulsions.

exceptions

Information in the NEC that follows code sections. Exceptions describe alternative methods, to be used under specific conditions, to the rules stated in the corresponding code sections.

excess air

The amount of air that is supplied to a furnace in excess of the theoretical minimum amount required for combustion.

excess cement

Cement slurry left in the wellbore after a squeeze, above the perforations it was intended to fill.

excess flow valve

A check valve that cuts off flow of product or vapor to a pressure tank car when flow rates exceed limits.

excessive current

Current above rating, which heats insulation until it fails rather than tripping anything by itself.

excessive heat

Temperature above the safe limit.

excessive pressure

Pressure above the safe limit.

excessive vibration

Vibration above acceptable limits, which signals imbalance, misalignment or a failing bearing.

excessive wear

Material loss beyond the expected rate.

Exchange for Physical (EFP)

Swapping a futures position for the corresponding physical cargo away from the exchange.

Exchange for Swap (EFS)

Exchanging a futures position for an equivalent swap position.

exchanger

A heat exchanger, transferring heat between two streams without mixing them.

exchanger surface

The heat transfer area available, which fouling reduces without any visible change.

exchanger tube

The tube carrying one fluid through an exchanger shell, where the heat transfer and the fouling happen.

excitation

Current flow that creates the magnetic field that causes induction in an AC generator.

excited state

An excited state is any state with energy greater than the ground state.

exciter

A device that produces and supplies direct current to a generator's rotor windings for AC generator excitation.

EXCLUSIVE NOR gate

A logic gate that produces a logic 1 output only when all of its inputs are the same (either logic 1's or logic 0's) and produces a logic 0 output when its inputs are not all the same.

EXCLUSIVE OR gate

A logic gate that produces a logic 1 output when only one of its inputs is a logic 1. It will produce a logic 0 output if it has more than one input of logic 1 or if it has no logic 1 inputs.

executing

Doing the work and coordinating the people and resources doing it.

exempt vs. nonexempt

Whether an employee is exempt from statutory overtime entitlement.

exhalation

Breathing out, and the valve path a respirator must provide for it.

exhaust gas

The gas produced when fuel burns in a boiler furnace. Exhaust gas must be pushed or drawn out of the furnace and discharged from the plant through the stacks.

exinite

A maceral group derived from spores and algae, oil-prone on maturation.

exit interview

The conversation on departure, whose value depends on whether anyone acts on what it reveals.

exit velocity

The speed of the mud jet leaving the bit nozzles.

exothermic

Releasing heat, which in a reactor means temperature runs away unless it is removed.

exothermic reaction

A reaction that produces heat after it is started.

exothermic reactions

Chemical reactions that give off heat.

expand

To increase in volume or size.

expanded accessibility

Technology widening participation for people previously excluded by disability or distance.

expander

A turbine extracting work from expanding gas, used to reach cryogenic temperatures.

expander-compressor

A machine which transfers energy from one gas stream to another by use of an expander and centrifugal compressor mounted on a common shaft.

expanding cement

A cement formulated to increase slightly in bulk volume as it sets, tightening its grip on pipe and formation.

expanding gate valve

A gate valve whose gate and segment spread apart at the end of travel to press against both seats, and collapse before moving.

expansion joint

A type of coupling that is used to compensate for expansion and contraction in a conduit run.

expansion valve

The component in a refrigeration system that lowers the refrigerant's temperature and pressure by allowing it to expand rapidly before flowing to the evaporator.

expectation

The value a quantity is estimated to take at a location away from where it was measured — the mean of its probability distribution.

expected monetary value (EMV)

The probability-weighted average outcome, used to compare risky alternatives.

expendable gun

A perforating gun whose charge cases break up on firing, so little or nothing is retrieved from the well.

expendable plug

A temporary plug run in the completion string so it can be pressure tested, then removed or destroyed to open the well.

expensed versus capitalized

Whether a cost hits this period's profit or is spread across the years it benefits.

expert system

A computer system that applies a body of encoded rules to reach conclusions in a specialist domain.

explicit vs. implicit data

What the customer told you against what their behavior revealed.

exploration

The first phase of petroleum operations — generating a play or prospect and drilling a well to test it.

exploration agreement execution

Signing the exploration contract, which starts the clock on the work commitment.

exploration and production (E&P)

The upstream activity of finding, appraising and producing oil and gas fields.

exploration block

A defined area licensed to a company for exploration.

exploration geophysicist

The specialist who acquires and interprets seismic to find prospects.

exploration geophysics

Measuring physical properties of the subsurface, chiefly by seismic, to image potential traps.

exploration phase

The phase of petroleum operations which covers the search for oil or gas by carrying out detailed geological and geophysical surveys followed by exploratory drilling.

exploration play

A group of prospects sharing the same reservoir, trap, seal and charge, so that they succeed or fail for the same reasons.

exploration process

The exploration process attempts to discover potentially commercial volumes of hydrocarbons through the successful drilling of well-defined exploration prospects, for which the risk of failure has been defined and reduced as much as cost effectively possible for each prospect, within its own subsurface context and its uncertainties.

E

E&P