Discover the IHRDC Energy Glossary_beta

A.G.A.

American Gas Association

A.N.S.I.

American National Standards Institute

A.P.I.

American Petroleum Institute

A.P.I. Gravity

The American Petroleum Institute gravity, a measure of how heavy or light a petroleum liquid is compared to water. If its API gravity is greater than 10, it is lighter and floats on water; if less than 10, it is heavier and sinks.

A.S.M.E.

American Society of Mechanical Engineers

AC Motor Controller

A device, or group of devices, that controls and protects the operation of an AC motor.

ADC

Analog-to-digital converter; a digital electronic component that converts an electrical signal into discrete binary values

AFCI

Arc Fault Circuit Interrupter. Similar to a GFCI, an AFCI shuts down power to a circuit when it detects an arcing situation. AFCIS help to prevent fires.

AIDS

A disease of the immune system characterized by increased susceptibility to opportunistic infections, to certain cancers and to neurological disorders. AIDS is caused by the human immunodeficiency virus and is transmitted chiefly through blood or blood products that enter the body's bloodstream, especially by sexual contact or contaminated hypodermic needles.

AND Gate

A digital logic gate that produces a HIGH output (1) only when all of its inputs are HIGH (1).

ANSI

The American National Standards Institute.

ANSI/ASQC Q90

Quality regulations developed by ANSI and ASQC that are the equivalent of ISO 9000.

ASCII

American Standard Code for Information Interchange standard set of 256 codes that express many of the common digits and characters used by most people throughout the world.

ASIC

ASIC is an application-specific integrated circuit chip customized for a particular use. Modern ASICs often have microprocessors and memory blocks, including ROM, RAM, EEPROM and flash memory.

ASQC

The American Society for Quality Control.

ATC

Automatic Temperature Compensator.

ATG

Automatic Temperature Gravity Selector.

AVO Analysis

AVO analysis is a technique by which geophysicists attempt to determine thickness, porosity, density, velocity, lithology and fluid content of rocks.

AWG System

A system used to indicate the size of wires used in routine electrical work; sizes range from 40 (smallest) through 0000 or 4/0 (largest).

Absolute Open Flow Potential

Absolute open flow potential (AOF) is the maximum flow rate a well could theoretically deliver with zero pressure at the middle of the perforations.

Absolute Permeability

The measurement of a rock's ability to flow or transmit fluids when only a single fluid, or phase, is present in the rock pore spaces.

Absolute Permeability, Specific Permeability

Sometimes referred to as specific permeability, the permeability when a single fluid, or phase, is present in the rock.

Absorbent

A type of chemical used in absorption refrigeration systems to control the pressure and temperature inside the system.

Absorber

The section of an absorption refrigeration system in which the refrigerant is absorbed by the absorbent. Also, an auxiliary vessel that separates specified components from a feed stream and produces one or more valuable products as a result.

Absorption

A chemical process in which one substance penetrates and is drawn into the bulk of another substance. In gas processing, a method of removing one or more components of a gas mixture by contacting the gas with a liquid, such as the removal of water vapor from natural gas by contact with a liquid desiccant (e.g., glycol) or the removal of acid gases (H2S, CO2) by contact with an amine solution.

Absorption Process

The attraction and retention of water vapor by glycol from gas, or of acid gases by amine from natural gas.

Acceleration

The rate of change of velocity per unit of time

Acceleration Ramp

The time it takes for a variable speed drive to speed up to a preset speed.

Acceptable entry conditions

The conditions that must exist in a permit space to allow entry and to ensure that employees involved with a permit-required confined space entry can safely enter into and work within the space.

Access

The ability to place information into and retrieve information from a storage device.

Accident

An unplanned and unexpected even. However virtually all accidents are preventable.

Accreditation of Prior Achievement (APA) [evidence]

A prior achievement, learning or experience that can be either performance or knowledge, e.g., certificates, qualifications, company awards, which must:

• Be specific enough to meet the standard
• Belong to the employee and be authenticated
• Be current enough to work now
• Actually prove either performance or knowledge
• Be presented in a way that allows it to be judged

Accumulator

A PLC memory word in which a timer or a counter stores the current time or count

Acetylene

A carbon and hydrogen compound that, when combined with oxygen, creates the extremely hot flame needed for welding and cutting

Acid

A substance that releases hydrogen ions when added to water.

Acid Gas

A gas that, when combined with water, produces acids or acidic solutions. The most common acid gases are hydrogen sulfide (H2S) and carbon dioxide (CO2).

Acid Hydraulic Fracturing

In acid hydraulic fracturing, the acid is injected into the formation above the fracture pressure of the adjacent formation rock.

Acid regenerator

A piece of equipment used to remove contaminants such as tar or constant boiling mixtures from hydrofluoric acid.

Acid settler

A component in the reaction section of an alkylation unit in which separation of the reactor effluent occurs; the heavier acid settles to the bottom, while the lighter hydrocarbons rise to the top.

Acid strength

The concentration of the acid catalyst in an alkylation process.

Acoustic

Acoustic, alternatively termed sonic, is the branch of physics concerned with the properties of sound.

Acoustic Image Log

Acoustic image logs are generated by bouncing an ultrasonic acoustic pulse from an acoustic imaging logging tool to, and then from, the borehole wall. The tool uses a transducer that both emits and records the acoustic pulse.

Acoustic Impedance

The product of density and velocity; a measure of the opposition that a system presents to acoustic flow resulting from an acoustic pressure applied to the system.

Acoustic Log, Sonic Log

A display of the travel time of acoustic waves versus depth in a well.

Acoustic Propagation

Acoustic propagation is the propagation of acoustic, or sonic, waves in a medium.

Acoustic Pulse

An acoustic pulse is produced by the alternate expansions and contractions of a transducer.

Acoustic Slowness

Acoustic slowness is the inverse of the acoustic velocity.

Acoustic Transmission

Acoustic transmission is the transmission of sounds through and between materials.

Acoustic Velocity, Sonic Velocity

Acoustic, or sonic velocity, is the velocity of an acoustic, or sonic, wave in a medium.

Acoustic, Sonic

Acoustic relates to sound or vibrational events.

Acreage

Land leased for oil and gas exploration and/or land for which a company owns the mineral rights.

Acres

A measurement of area. 1 acre equals 43,560 square feet. 1 mile x 1 mile in area equals 640 acres, which is equal to 259 hectares, the common measurement of area in many countries of the world. 1 square kilometer is equal to 100 hectares.

Action level

A concentration designated in OSHA Regulations (29 CFR part 1910) for a specific substance, calculated as an eight-hour time-weighted average, which initiates certain required activities such as exposure monitoring, medical surveillance, and hearing protection. The current action level for noise is 85 decibels.

Activated Carbon

An adsorbent created by treating coal or carbon with steam in a process called activation, producing a honeycomb structure that can trap individual ions and molecules of dissolved substances.

Activated Sludge

Sludge that contains micro-organisms; used for biological treatment of wastewater.

Activated alumina

An adsorbent used to remove moisture from gases and liquids.

Activated carbon filter

A type of specialty filter that is designed to control odors.

Activation, Neutron

Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The excited nucleus often decays immediately by emitting gamma rays, or particles such as beta particles and alpha particles.

Active Light

The light on a network device that blinks whenever data is being transmitted or received

Active device

A device that has the ability to change its internal resistance.

Active energy

Hazardous energy that is present in equipment as a source of power for the equipment.

Active sites

Acidic areas on the surface of a catalyst particle where the cat cracking reaction occurs.

Activity

The ability of a catalyst to crack hydrocarbons; determined by the number or strength of the catalyst's active sites.

Actuator

A device used to operate valves or other equipment in process systems. In limit switches, it is the part that something moves to operate the switch mechanism. Common types include pneumatic, hydraulic, motor, and solenoid actuators.

Acute

Having a rapid onset and relatively short but severe course. The time scale depends on the particular disease but is generally measured in days or weeks.

Acute angle

Any angle between 0 degree and 90 degree

Acute effects

Effects that develop immediately after brief exposure to a hazardous chemical

Acute health effect

An adverse health effect that occurs rapidly as a result of a single or short-duration exposure to a health hazard and is typically short in duration.

Acute health effects

Health effects that occur as a result of a single or short-duration exposure to a chemical.

Adaptive Control

A controller enhancement in which an automatic means is used to adjust the controller's response to its inputs based on previous experience

Additives

Additional components that are added to a gasoline blend to produce a product that meets customer requirements.

Address

A unique alphanumeric identifier for an input terminal, an output terminal, or a memory location

Adhesive Force

A molecular force that exists between unlike molecules

Adiabatic

Adiabatic process is a conversion that occur without input or release of heat within a system

Adjustable nozzle

A nozzle for a fire hose that can be adjusted to provide a straight stream or a fog pattern.

Adjusting Ring

The part of a spring-loaded safety valve used to adjust blowdown.

Adjusting Screw

The part of a spring-loaded safety valve or relief valve used to adjust the tension of the spring which controls the set point.

Administrator

A user role in CMS Online. Administrators can manage user accounts, edit users' information, add and delete users, assign and manage assessments, assign supervisors, set system-wide settings, work with competency models and a variety of other tasks related to the set-up and management of CMS Online.

Adsorbent

A natural or synthetic drying substance that dries material by removing gas or liquid molecules.

Adsorber

An auxiliary vessel that uses a porous solid to remove impurities, such as dissolved solids and gases from liquids.

Adsorption

A chemical process in which a thin layer of molecules adheres to the surface of a porous solid material. Used as a method for removing liquids and gases from mixtures, such as the removal of water from a gas stream by contact with a solid desiccant (e.g., silica gel) or the adhesion of liquid hydrocarbons to activated carbon.

Aeolian

Aeolian, or eolian, refers to structures that are created by the wind.

Aeolian Depositional Environments

Aeolian depositional environments are those in which sediment deposition is primarily governed by wind.

Aeolian Deposits

Sediments that are transported by wind and then deposited.

Aeration

A process that supplies oxygen for an activated sludge process

Aerator

A device for mixing air into a liquid such as wastewater

Aerobic Process

A biological treatment process that requires the presence of oxygen.

Aerosol

A stream of product containing both gases and liquids.

Afterburning

The igniting of fuel in the convection section of a furnace, which can be caused by an air leak in the convection section combined with insufficient air at the burners. Also, a condition in which excessive amounts of carbon monoxide are allowed to burn to carbon dioxide in the dilute phase of a regenerator.

Afterflow

Afterflow is the flow associated with wellbore storage following a surface shut-in. When a well is first shut in at the surface, flow from the formation into the bottom of the wellbore continues unabated until compression of the fluids in the wellbore causes the downhole pressure to rise. If the wellbore fluid is highly compressible and the well rate is low, the afterflow period can be long. Conversely, high-rate wells producing little gas have negligible afterflow periods.

Agglutinated

Agglutinated refers to the tests being formed from foreign particles that are "glued" together with a variety of cements.

Agitation

Mixing or otherwise causing rapid and close contact between a solute and a solvent.

Agitator

A propeller-like mixing device located inside a reactor's shell.

Aim

The desired value of a monitored variable. Ideal process centerline in a CUSUM system. Also called "target"

Air Binding

A condition in which air is trapped in a heat exchanger, feedwater heater, or condenser, either blanketing the tubes or blocking the flow of fluid, typically as a result of improper venting.

Air Ejector

A device, sometimes called a jet pump or a steam jet air ejector (SJAE), that uses high-velocity fluid flow to create a vacuum that removes air and non-condensable gases from a condenser

Air Permeability

The permeability measurement resulting from the use of the compressible fluid equation is known as the air permeability.

Air Registers

Adjustable openings that admit air into a furnace

Air Removal System

A system that removes air and non-condensable gases from a condenser and helps establish and maintain the vacuum in the condenser on startup

Air Rich

An operating condition in which more air than is necessary for complete combustion is supplied to the boiler

Air bag

An inflatable bag mounted in the steering column, under the dashboard or on the doors of a car that cushions the driver and/or passengers by inflating automatically in the event of collision.

Air bag (air cell)

A flexible bag inside some conservator tanks that separates the air in the tank from the oil in the tank.

Air core inductor

An inductor that uses air as the only core material.

Air intake

An opening that allows air to enter a duct or go directly to a fan.

Air pollution

Emissions that can cause harm to people, animals, or plants and are present in the environment in large enough amounts to actually be harmful.

Air purifying respirator

A mask or device that cleans or purifies air by filtering out airborne particulates such as dust, or chemically adsorbing relatively small amounts of toxic vapors and gases.

Air supplied respirator

A respirator that supplies users with breathable air from a clean air source, such as a compressed air cylinder

Air-operated drum pump

A small pump commonly used to transfer thick liquids, such as grease, from large drums to smaller containers.

Air-purifying Respirator

A device used to filter out particulates, vapors, or gases that could be hazardous if inhaled, either by filtering out particulates or chemically adsorbing relatively small amounts of toxic vapors and gases.

Air-supplied respirator

A respirator that supplies the user with breathable air from a clean air source, such as a compressed air cylinder or a self-contained air supply; used in work areas with large concentrations of hazardous gas or insufficient oxygen to support life.

Airfoil fan

A type of centrifugal fan that has blades shaped like the cross-section of an airplane wing.

Alarm

Any condition that represents a departure from the desired condition and that someone needs to acknowledge. For example, a hot motor, missed production goal, empty hopper, absence of flow, excess absenteeism, etc

Algorithm

An algorithm is a specific procedure for solving a well-defined computational problem.

Alias

The name given to a device to identify it in a ladder diagram; synonym for label, tag, or symbol

Alkylate

A high-quality gasoline blending component produced in an alkylation unit, typically used for motor fuel or aviation fuel.

Alkylation

A chemical reaction in which an olefin reacts with isobutane to produce an isoparaffin (alkylate).

Alkylation unit

A reactor system that uses a catalyst in a chemical reaction to combine olefins and isobutane to make alkylate.

Allowable Ampacity

The maximum amount of current that an insulated conductor can carry without overheating

Alternate Mode Control

A vertical control that allows an oscilloscope to display two high-frequency signals at the same time. This done by alternately tracing each signal at a speed quick enough so that the eye perceives both signals at the same time.

Alternating Current

Current that flows in one direction and then reverses and flows in the opposite direction.

Alternating current (AC)

Current that periodically reverses direction as it flows.

Ambient Temperature

The temperature of the air, fluid, or environment surrounding a vessel, device, or area.

American Petroleum Institute (API)

The American Petroleum Institute is the oil and gas industry's trade organization. API's research and engineering work provides a basis for establishing operating and safety standard issues and specifications for the manufacturing of oil field equipment and furnishes statistical and other information to related agencies. Visit API at www.api.org.

American Wire Gauge (AWG)

Wire sizing standard that is a measure of the thickness of copper, aluminum, and other wiring

Amine

A chemical compound derived from ammonia by replacement of hydrogen by one or more hydrocarbon radicals. Mixed with water, it absorbs acid gases (hydrogen sulfide and carbon dioxide) from liquid and gas fractions. Common name for alkanolamines.

Amine (Lean)

Amine solution that is free of acid gases.

Amine (Rich)

Amine solution that has absorbed acid gases.

Amine Seal

A level of amine solution between the tray and downcomer weir which forces gas/vapor to pass through bubble caps.

Amine treater

A piece of equipment that uses amine to remove hydrogen sulfide from an alkylation unit feed stream.

Ammeter

A device used to measure and indicate current flow

Ampacity

The amount of current that a wire can carry without overheating

Ampere

The unit of measurement of electrical current. In the meter-kilogram-second system, it is the steady current that, when flowing in straight parallel wires of infinite length and negligible cross section separated by one meter in free space, produces a force of 2 × 10⁻⁷ newtons per meter of length. It is also the current produced in a circuit by 1 volt acting through a resistance of 1 ohm.

Ampere (Amp)

A unit of electrical current.

Amperes

The ampere is a measure of the amount of electric charge passing a point per unit time. It is often shortened to amp.

Amplifier

A device that receives a signal at its input and delivers a larger, undistorted version at its output.

Amplifier Circuit

A circuit that produces an output signal that is a larger version of the input signal.

Amplify

To produce a larger, undistorted version of an input signal.

Amplitude

The maximum extent of a vibration or oscillation, measured from the position of equilibrium (null point). Also, the magnitude of a quantity or the strength of a signal.

Amplitude versus Offset (AVO)

Amplitude versus offset is the variation in seismic reflection amplitude with a change in distance between shot point and receiver that indicates differences in lithology and/or fluid content in rocks above and below the reflector.

Anaerobic Process

A biological treatment process that occurs in the absence of oxygen.

Analog

A measurement that varies continuously in relationship to an actual physical condition. Also refers to the one-way communication from a transmitter to a controller or DCS in 4-to-20 milliamps, 3-to-15 psi, or other analog scale.

Analog Data

Data that is represented in a physical way, stored as voltages and represented as lengths.

Analog Display

A display that indicates values by converting current flow into the motion of a pointer across a scale

Analog Module

A type of I/O module that converts a varying voltage or current signal into a digital signal, or vice versa

Analog Signal

A continuous signal similar to a sine wave signal, such as the kind of signal that electro-mechanical relays receive from current transformers or voltage transformers.

Analytical Variable

A process variable that is based on the physical or chemical composition of materials

Analyzer

An instrument or device that measures and indicates physical or chemical characteristics based on the composition of a material or conditions in a process.

Analyzer Transmitter

A device that senses an analytical process variable, such as pH, and produces a signal that can be used to monitor or control the operation of a process system

Anchorage

A secure point of attachment for lifelines, lanyards, and similar devices that are connected to a body harness.

Anchorage Connector

A connector, such as an eyebolt, that is installed at an anchorage; the connector enables other parts of a fall arrest system to be easily connected and disconnected at the anchorage.

Ane

A suffix for the name of a hydrocarbon that has a straight chain of carbon atoms linked together by single bonds.

Angle

The shape that is made when two straight lines come together

Angle Valve

A type of globe valve in which the outlet is at a right angle to the inlet.

Angle grinder

A large, portable power grinder that has a handle mounted on the side of the casing and a grinding wheel mounted at a right angle to the tool's motor. Also called a side grinder.

Angular Unconformity

An angular unconformity is an unconformity in which horizontally parallel strata of sedimentary rock are deposited on tilted and eroded layers, producing an angular discordance with the overlying horizontal layers.

Anhydrite

Anhydrite is a mineral, anhydrous calcium sulfate, CaSO4.

Anion

A negatively charged ion

Anions

Negatively charged ions.

Anisotropic

Anisotropic is having a physical property that has a different value when measured in different directions.

Anisotropy

The property of being directionally dependent. Geological formations can have directionally dependent properties, and in seismics it refers to the difference between horizontal and vertical velocities.

Anisotropy, Anisotropic

Anisotropy is the property of being directionally dependent.

Annihilation

Annihilation is the process whereby the positron and electron disappear immediately after pair production takes place.

Annulment

Act of reducing to the lowest possible level by cancelling or nullifying terms.

Annulus

The space between two concentric objects, such as between drill pipe and casing or between a core barrel and the borehole wall, where fluid can flow. Also, the area between the casing and the production tubing.

Anode

The part of a corrosion cell at which electrons are released and positive metal ions are formed.

Anthracite Coal

A hard variety of coal that is used to filter organic materials out of wastewater

Anticline

A convex-upward formation of rock layers, which may form a trap for hydrocarbons.

Antilock braking system (ABS)

A braking system that when pressed hard (like in a panic stop or accident) the ABS pumps the brakes up to 30 times/sec. This occurs in an alternating pattern, left front/right rear and right front/left rear. This system helps the driver maintain control and stop the car in a straight line rather than spinning out of control.

Antithetic Faults

Antithetic faults are usually smaller faults which dip in the opposite direction of the major fault.

Anvil

An iron or steel block on which metal objects are hammered into shape

Apparent Dip

Apparent dip is the angle that a plane makes with the horizontal measured in any randomly oriented section rather than perpendicular to strike.

Apparent Power

The total power that a utility must produce to meet the demands for both working power and non-working power (power stored and returned by inductance and capacitance); equal to voltage times current in any circuit.

Appraisal of an Exploration Discovery

A process for evaluating an exploration discovery by steadily reducing subsurface uncertainties sufficiently to allow decision-makers to proceed with confidence in an economically viable, optimized field development with a good understanding and full description of the remaining uncertainties.

Aqueous Depositional Environment

An aqueous depositional environment entails the deposition of sediments in oceans, seas, rivers, deltas and lakes.

Aquifer

A body of rock or underground layer of water-bearing permeable rock or unconsolidated materials (gravel, sand, silt, or clay) whose fluid saturation, porosity, and permeability permit the production of groundwater, which can be extracted using a water well.

Aquifer Storage Field

The underground storage of natural gas in a porous and permeable rock formation topped by an impermeable cap rock, the pore space of which was originally filled with water

Arc fault

A fault that occurs when current jumps through the air between two terminals that have different potential.

Archie's Law

In petrophysics, Archie's law relates the in-situ electrical conductivity (C) of a porous rock to its porosity and fluid saturation of the pores.

Archimedes' Principle

Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces.

Architect

A person who designs buildings and supervises their construction

Arcing

Current flow through air, as can occur across an open switch.

Arcuate to cuspate-shaped

Arcuate refers to something that is curved or bent like a bow or arc. Cuspate-shaped refers to something that is triangular or pointed, resembling a cusp or tooth.

Area

The two-dimensional measurement of a defined region, generally obtained by multiplying width times length and expressed in square units such as square inches, square feet, or square miles.

Arenite

Arenite, or sandstone, is a clastic sedimentary rock composed of sand-sized minerals and rock grains. Most sandstone is composed of quartz and/or feldspar.

Argillaceous beds

Argillaceous beds refer to sedimentary rock layers that are primarily composed of clay and silt-sized particles, which often contain a high proportion of clay minerals. These beds are commonly found in shales, mudstones, and argillites.

Armature

The movable part of a magnetic contactor that allows contacts to close. In a DC motor, it refers to the entire rotating assembly including the shaft, armature core, armature windings, and commutator.

Armstrong Oscillator

An LC oscillator that produces a sinusoidal wave. A transformer arrangement is used for the feedback circuit.

Aromatic

A cyclic hydrocarbon whose carbon atoms are connected by both double bonds and single bonds, typically a high-octane compound produced by applying heat and pressure to naphtha and reforming the hydrocarbon molecules.

Array Dielectric Logging Tool

Array dielectric logs acquire dielectric data at a number of different frequencies, giving a resistivity profile at those different depths of investigation. They also measure the signal phase shift, from which can be derived the water-filled porosity.

Array Induction Tool, Log

An array induction tool is a tool that consists of several mutually balanced arrays whose signals are recorded separately and combined in software to produce the response desired. Typically, there is one transmitter and five to ten pairs of receivers.

Array Laterolog

An electrode device with multiple current electrodes configured in several different ways to produce several different responses. A typical array consists of a central electrode emitting survey current with multiple guard electrodes above and below it. Current is sent between different guard electrodes to achieve greater or less focusing, with greater focusing providing greater depth of investigation. About five basic measurements are obtained, which may be further improved by software focusing to ensure proper response in a wide range of conditions.

Array Sonic Tool, Log

An array sonic is a type of acoustic logging tool that uses a large number of receivers, typically 4 to 12.

Article

A subdivision of the chapters in the NEC. Beginning with Article 90 "Introduction" and ending with Article 820 "Community Antenna and Radio Distribution Systems," the NEC articles are the main topics of the code.

Artificial Intelligence

The ability of some controllers to "learn" from normal process operation and thus improve their response. Also referred to as "fuzzy logic."

Artificial Lift

A method of bringing well fluids to the surface when the downhole pressure is not great enough to force the fluids up naturally.

Artificial Lin

A method of bringing well fluids to the surface when the downhole pressure is not great enough to force the fluids up naturally.

Artificial Neural Networks (ANN)

Artificial Neural Networks, usually just termed neural networks or neural nets, are computing systems inspired by the biological neural networks that constitute animal brains. An ANN is based on a collection of connected units or nodes called artificial neurons, which loosely model the neurons in a biological brain.

Ash Gate

An internal gate that separates the bottom of the boiler from the rest of the bottom ash handling system

Ash Hopper

A bin that is used to collect the ash that is left over from combustion

Asphaltic crude oil

Crude oil that contains a high proportion of asphalt.

Asphalts

Heavy products made from the bottom of the crude oil barrel and used for applications such as paving, roofing, and waterproofing.

Assessment

A process to determine gaps between an individual's current skills and those required of a particular position. It begins with an Employee Assessment and a Supervisor Assessment and ends with an Assessor Assessment of the results by an independent third party, after which a Competency Development Plan can be built.

Assessor

A person (usually a supervisor) who assesses an employee's performance and/or related knowledge in a range of tasks to determine if the competence demonstrated meets the requirements of the specified standards.

Assessor Assessment [formerly Verification]

An objective assessment by a third-party SME to resolve differences between employee and supervisor ratings by providing an opportunity for the employee to demonstrate or document skill. The process ensures the system remains objective and fair across the organization

Asset Development Process

The asset development process is a sequential process, often with stage gates, which progresses an oil and gas property through the following stages: a) Identify and assess exploration opportunities. b) Analyze alternative development options. c) Optimize preferred development plan. d) Execute development plan. e) Manage production life cycle.

Assets

Assets are items that have earning power, or some other value, to their owner.

Assistant Secretary

The Assistant Secretary of Labor for Occupational Safety and Health, U.S. Department of Labor, or designee.

Astable Multivibrator

A multivibrator that has no stable state.

Asymmetry

A characteristic of many process loops in which the process response differs in either amount or speed depending on the direction of change.

Asynchronous

These inputs; set and reset, regardless of the status of the clock signal can set or reset the flip-flop because they can override the synchronous (normal data) inputs.

Atmospheric Pressure

The atmospheric pressure exerted at a certain location. At sea level, it is about 14.73.

Atmospheric Pressure Base

The atmospheric pressure exerted at a certain location. At sea level, it is approximately 14.73.

Atmospheric tank

A tank designed to store liquids at or near atmospheric pressure, ranging from 0 psig to 0.5 psig.

Atmospheric tower

A tower whose interior is kept at or near atmospheric pressure; used in a crude oil distillation unit to separate basic fractions from incoming crude.

Atom

The smallest particle to which an element can be reduced while still retaining the properties of that element; an elemental particle that makes up all forms of matter.

Atomic Mass

The atomic mass is the quantity of matter contained in an atom of an element.

Atomic Number

Atomic number is the number of protons in the nucleus of an atom, which is characteristic of a chemical element and determines its place in the periodic table.

Atomic Particles

Protons, electrons, and neutrons. Protons are positively charged, and electrons are negatively charged. Neutrons are not charged, so they are not considered when looking at an atom's electrical characteristics.

Atomizer

The part of an oil burner that uses pressure, steam, or air to change oil into a mist

Attemperator

A device that sprays water into the steam flowing through a superheater or reheater to prevent the final outlet steam temperature from exceeding established limits. Also called a desuperheater

Attendant

An individual stationed outside one or more permit spaces who monitors the authorized entrants and who performs all attendant's duties assigned in the employer's permit space program.

Attenuation

The reduction of the amplitude of a signal, electric current, or other oscillation; a decrease in signal voltage during its transmission from one point to another.

Attributes

Items that can be counted

Auctioneering Control

A system of control in which the controlled variable is measured in two or more places, and the highest measured value is selected as the loop input

Audiometric test

A hearing test that measures the ear's ability to detect sound at specific frequencies or tones.

Audit

An evaluation performed to make sure that the individual components of a quality system are operating effectively and that procedures are being followed properly.

Auger

A device that bores down into large quantities of solid materials to obtain samples

Authigenesis

Authigenesis is the process whereby a mineral or sedimentary rock deposit is generated where it is found or observed.

Authigenic

An authigenic mineral or sedimentary rock is one that was generated where it is found. Authigenic sedimentary minerals form during sedimentation by precipitation or recrystallization instead of being transported from elsewhere by water or wind.

Authorized entrant

An employee who is authorized by the employer to enter a permit space.

Auto-assess

In cases where an assessor assessment is not required, an Administrator can select assessments to auto-assess, which records the lower of the employee and supervisor assessment scores for each competency unit as the Final Assessment Result (FAR).

Auto-tune

A feature of some single-Loop and multiple-loop controllers that automatically sets optimized loop parameters

Auto-tuning

A controller enhancement that imposes a process upset to test the system response automatically and then resets the controller's parameters based on that response

Automatic Control

A basic form of process control in which input devices, controllers, and output devices control a process with minimal input from operating personnel

Autoranging

A feature on most digital test instruments that allows the instrument to control the measurement range automatically

Auxiliary Contacts

Contacts used in a magnetic contactor for auxiliary control functions such as completing current flow to an indicating light used to indicate a motor is on

Auxiliary Relay

A type of relay that only operates when it receives a signal from a protective relay.

Auxiliary Steam

Steam used for purposes other than driving a main turbine or heating feedwater.

Auxiliary drawings

Supplemental drawings that are often included with the working drawings in a set of blueprints

Auxiliary vessel

A secondary vessel associated with a process system.

Averaging

A processing technique used by digital oscilloscopes to eliminate noise in a signal

Awareness (Competency Level 1)

Has general, limited comprehension of a particular topic / Able to identify and define key elements of the topic / Understands basic concepts and principles / Able to provide basic assistance / Able to carry out assigned tasks with guidance and monitoring

Awkward postures

An ergonomic risk factor involving postures that differ significantly from neutral positions. Awkward postures include repeated or prolonged reaching, twisting, bending, kneeling, squatting, and working overhead with your hands or arms.

Axial

Relating to a line or direction parallel to the axis of a shaft.

Axial Clearance

The distance that a thrust bearing allows a pump shaft to move in an axial direction

Axial Clearance Check

A measurement taken with a dial indicator to determine the amount of thrust bearing wear

Axial Thrust

A force that is exerted parallel to the centerline, or axis, of a shaft.

Axial air flow

Air flow that is parallel to the shaft of a fan.

Axial fan

A fan that produces axial air flow; typically moves large quantities of air or gas at relatively low pressure.

Axial impeller

An impeller that produces flow that is basically parallel to the shaft of a mixer.

Axially Split Pump

A pump with a casing that is split parallel to, or along, the axis of the pump's shaft

Azeotrope

A mixture of components that behaves as if it were a single component with a constant boiling point.

Azeotropic Distillation

A type of distillation that uses a solvent or two distillation towers in a special arrangement to separate mixtures whose components form azeotropes and are difficult to separate.

Azimuth

The horizontal angle or direction of a compass bearing.

Azimuthal Laterolog

An azimuthal laterolog is a type of electrode device that is able to measure resistivity in different directions around the sonde. In most laterologs, the electrodes are cylinders that average the resistivity azimuthally around the sonde. In azimuthal laterologs, the electrode is segmented radially in several portions, each of which responds to the resistivity in the direction it is facing.

accessory grains

An accessory grain is a non-essential grain found in rocks, typically rich in trace elements and present in small quantities.

accommodation space

The space available for the deposition of sediments.

accretion

The process of growth or increase, typically by the gradual accumulation of additional layers or matter. In geology, accretion is the process where material such as sediment, volcanic arcs, seamounts, oceanic crust, or other igneous features is added to a tectonic plate, causing it to grow larger, frequently on the edge of existing continental landmasses.

acicular

Acicular describes a mineral habit where crystals are slender and needle-like, tapering to a point. These crystals are typically much longer than they are wide, often forming radiating or fan-shaped aggregates.

aeolian environments

An aeolian environment is a depositional environment in which sediment deposition is primarily governed by wind.

aeolianite

Aeolianites are rocks formed by the lithification of sediments that are deposited by wind processes.

arcuate

Arcuate refers to something that is curved or bent like a bow or arc.

arkosic

Arkosic sandstone is a detrital sedimentary rock that contains at least 25% feldspar.

array

An array is generally a group of source or receiver points along a seismic line (known as an inline array), respectively

array length

The array length is the distance from the first receiver in an array to the last receiver in the array.

arrays

A geometric arrangement of seismic receivers (geophones) with signals recorded by one channel, which can contain numerous closely spaced geophones. An areal array involves the placement of receivers around the source (often in a circular or oval shape) as opposed to in a straight line radial to the shot.