Oil and gas terminology · MLC-0103

Oil and gas terms: B (292)

• Back flowThe reversal of fluid movement in a wellbore or pipeline, where fluid flows in the opposite direction to the...
• Back inA contractual right held by a grantor, such as a landowner or original leaseholder, to regain a percentage of...
• Back offTo unscrew one threaded component of the drill string from another downhole. This is an intentional...
• Back propagationThe numerical extrapolation, in seismic imaging, of a recorded wavefield backward in time or depth through a...
• Back strippingA geological modeling technique used to progressively remove the effects of sediment loading and compaction...
• Back upTo hold one tubular still with a backup tong or wrench while a second tong turns the mating joint, either to...
• Back washTo reverse the flow of fluid in a wellbore or pipeline to clear an obstruction or to clean a filter or...
• BackflowThe unintended reversal of fluid movement within a wellbore or production system, causing fluid to move...
• Background gasThe normal, low level of hydrocarbon gas detected in the drilling fluid as it returns to the surface...
• BackoffThe process of unscrewing a threaded connection in the drill string or casing string downhole. This operation...
• BackpressureThe resistance to fluid flow in a wellbore or pipeline, exerted by downstream equipment or the pressure of...
• Back-pressure valveA one-way valve installed in the tubing hanger or tubing string that permits fluids to be pumped down the...
• BackscatterThe portion of wave energy that is reflected or scattered from a medium back toward the energy source. In...
• BacksideThe annular space between the production tubing and the casing in a well, or between two strings of casing...
• Backup curveA secondary or alternative log curve recorded simultaneously with the primary measurement, intended for use...
• Backup ringA component used in conjunction with an O-ring or other elastomeric seal to prevent extrusion of the seal...
• Backward multiple-contact testA laboratory test that mimics repeated contact between fresh injection gas and the oil left near the...
• BackwashThe procedure of reversing fluid flow through a filter, screen, or wellbore to remove accumulated solids or...
• BactericideA chemical additive used in water-based drilling fluids to kill or inhibit the growth of bacteria and other...
• Bad holeA wellbore condition characterized by irregularities, such as washouts, caving, or rugosity, that can...
• Balance pointThe point, in coiled tubing or snubbing work in a live well, at which the weight of the string in the hole...
• Balanced arrayA configuration of logging tool transmitters and receivers designed to minimize the influence of the borehole...
• Balanced plugA cement plug placed in a wellbore where the hydrostatic pressure of the cement column is equalized with the...
• Balanced-activity oil mudAn oil-based or synthetic-based drilling fluid whose internal water phase has been treated to match the water...
• Ball catcherA device installed in a wellbore to retrieve or retain a dropped ball, often used in conjunction with...
• Ball diverterA downhole tool that uses a dropped ball to redirect fluid flow from one path to another, typically to...
• Ball dropperA surface device used in multistage fracturing operations to sequentially release balls of specific sizes...
• Ball launcherA piece of surface equipment designed to inject spherical balls into a wellbore under pressure, often during...
• Ball operatedDescribing a downhole tool or device that is activated by dropping a spherical object, or ball, from the...
• Ball sealersSmall, buoyant balls made of rubber, nylon, or a degradable polymer that are pumped with stimulation fluids...
• Ball valveA quarter-turn valve that uses a hollow, pivoting ball to control flow through it. The ball has a bore...
• BalloutThe condition reached in a stimulation treatment that uses ball sealers for diversion, when the balls have...
• BandA specific range of frequencies within a spectrum, such as the electromagnetic or seismic spectrum. Seismic...
• Band passA type of filter that allows frequencies within a specified range to pass through while attenuating...
• Band rejectA type of filter that attenuates frequencies within a specified range while allowing frequencies outside that...
• Band-limited functionA mathematical function whose Fourier transform is zero outside of a finite frequency interval or band...
• Bank firingA perforating technique in which a group of guns is run together on a single trip and then all of them are...
• BarefootDescribing a well completion method where the final section of the wellbore is left without casing or a...
• Barefoot completionA well completion method in which the production casing is set just above the reservoir, leaving the...
• BariteA heavy, non-metallic mineral composed of barium sulfate (BaSO4), characterized by its high specific gravity...
• Barite plugA dense plug formed by pumping a slurry of barite in water or oil-based fluid, usually with a dispersant, so...
• Barrel equivalentA laboratory volume of 350 milliliters of mud that stands in for one 42-gallon oilfield barrel. One barrel...
• Barrel pumpA type of positive displacement pump, often a rod pump, designed to lift fluids from a wellbore. It consists...
• Barrels of liquid per dayA unit for the total liquid production rate of a well or field, counting both oil and water produced over a...
• Barrels of oil per dayA unit for the rate at which crude oil is produced from a well, reservoir or facility, abbreviated BOPD. The...
• Barrels of water per dayA unit of measure for the volume of water produced from a well or field over a 24-hour period. This includes...
• BaryteA naturally occurring mineral, primarily barium sulfate (BaSO4), used as a weighting agent in drilling fluids...
• Base exchangeThe reversible process where ions in a solution, such as drilling mud filtrate, are exchanged with ions...
• Base logThe initial set of wireline logs acquired in a newly drilled well, typically including resistivity, porosity...
• Base mapA map that displays fundamental geographic or geologic information, such as topography, cultural features, or...
• Base of weatheringThe boundary separating the near-surface, low-velocity weathered layer from the underlying, higher-velocity...
• Base oilThe continuous liquid phase of an oil-based drilling fluid, which can be diesel, mineral oil, synthetic oil...
• Base slurryA mixture of cement and water, often with minimal or no additives, prepared before the addition of other...
• Base stationA stationary global positioning system (GPS) receiver that records satellite signals at a known location to...
• BaselineA reference measurement or survey conducted at an initial time, against which subsequent measurements are...
• BasementThe underlying, older, and more crystalline rock complex upon which younger sedimentary basins are deposited...
• Basic waveletThe elementary seismic signal produced by a single, isolated, and sharp reflector, representing the earth's...
• BasinA large-scale depression in the Earth's crust where sediments accumulate over geological time, often forming...
• BasketA downhole tool designed to catch and retrieve debris or junk from the wellbore. It typically features a...
• Basket flowmeterA production logging tool whose spring-loaded or inflatable basket opens against the casing to funnel the...
• Basket subA specialized downhole tool run as part of the drill string, designed to catch and retain junk or debris that...
• Batch mixerA piece of surface equipment consisting of one or more tanks with agitators, used for preparing specific...
• Batch treatmentA method of introducing chemicals into a well or pipeline system intermittently rather than continuously...
• BathyalRelating to the marine depositional environment of the continental slope, located between the shallower...
• BatteryA centralized facility in an oil or gas field where production from multiple wells is gathered, separated...
• Battery siteThe physical location or plot of land where a production battery is situated. This site contains all the...
• Bayesian inferenceA statistical method that updates the probability for a hypothesis as more evidence or information becomes...
• Bayesian methodA statistical approach to data analysis that uses Bayes' theorem to update the probability of a hypothesis as...
• Bayesian probabilityA concept of probability that interprets the likelihood of an event as a degree of belief, which can be...
• BBL or bblA standard unit of volume for crude oil and other petroleum products, equivalent to 42 US gallons or...
• BcA dimensionless unit, abbreviated Bc, for the consistency of a cement slurry measured in a pressurized...
• BcfA unit of volume for natural gas, representing one billion (1,000,000,000) cubic feet. This large unit is...
• Bcf/dA unit of measure for the daily production or consumption rate of natural gas, representing one billion cubic...
• Bead tracerSmall, solid particles containing a radioactive isotope, injected into a wellbore to measure fluid velocity...
• BeamA structural component of a pumping unit, often called a walking beam, that transmits vertical motion to the...
• Beam pumpA type of artificial lift in which a surface pumping unit, driven by an electric motor or engine, converts...
• BeanA small, removable orifice or choke installed in a flow line to restrict fluid flow and regulate production...
• Bean chokeA fixed-orifice device used to restrict fluid flow and control the production rate from a well. It consists...
• Bearden units of consistencyA dimensionless scale for how thick a cement slurry is, read from a pressurized consistometer that stirs the...
• Beaufort scaleA system for estimating wind speed based on observed sea conditions or land effects, rather than direct...
• BedA distinct layer of sedimentary rock or unconsolidated sediment, distinguishable from layers above and below...
• Bed thicknessThe vertical dimension of a single sedimentary bed, measured perpendicular to its bedding planes. This...
• BedrockThe solid, unweathered rock that lies beneath loose surface materials such as soil, sand, gravel, or...
• BelA logarithmic unit of measurement that expresses the ratio of two values of a power or root-power quantity...
• Bell nippleA large-diameter pipe that connects the top of the blowout preventer (BOP) stack to the flow line, directing...
• BenchmarkA point of known elevation or position that serves as a reference for surveying and mapping. In geophysical...
• BeneficiateTo process a raw mineral, such as bentonite or barite, to improve its physical or chemical properties for use...
• BeneficiationThe process of improving the physical or chemical properties of a raw material, such as barite or bentonite...
• Benioff zoneA planar zone of seismicity that dips into the Earth's mantle beneath an oceanic trench and volcanic arc...
• BenthicRelating to the bottom of a body of water, such as an ocean, lake, or river, and the organisms that live...
• BenthosThe community of organisms that live on, in, or near the bottom of a body of water, such as the seabed or...
• BentoniteA highly absorbent clay mineral, primarily composed of montmorillonite, formed from the alteration of...
• Bentonite equivalentA way of reporting the methylene blue test, which gauges the reactive clay content of a water-based mud, as...
• Bevel-gear-operated (BGO) valveA valve equipped with a bevel gear mechanism to assist in opening and closing the valve, particularly for...
• BHAThe section of the drill string located just above the drill bit, comprising specialized tools and...
• BHCTThe temperature of the drilling fluid at the bottom of the wellbore during circulation, abbreviated as...
• BHPThe fluid pressure at the bottom of a well, made up of the hydrostatic pressure of the fluid column plus any...
• BHSTThe bottomhole static temperature, which is the temperature of the formation at the bottom of the wellbore...
• BHTThe bottom hole temperature, which is the temperature measured at the deepest point reached in a wellbore...
• BiasA systematic error in a measurement or estimation that causes results to deviate consistently from the true...
• Bias weldA weld cut at an angle across the width of the flat steel strip that is formed into coiled tubing, joining...
• BicarbCommon shorthand for sodium bicarbonate, a mud additive used mainly to treat cement contamination in...
• BicarbonateAn anion (HCO3-) present in drilling fluids, often introduced as sodium bicarbonate to treat calcium...
• Bicenter bitA specialized drill bit designed with two cutting structures that allows it to drill a larger diameter hole...
• Bichromate saltA chromium-based chemical compound, such as sodium dichromate, formerly used as a deflocculant and...
• Bid and study agreementA preliminary contract between parties that outlines the terms for jointly evaluating a potential oil and gas...
• Big dataExtremely large and complex datasets that cannot be easily processed or analyzed using traditional data...
• Big hole chargeA specialized shaped charge designed to create a larger-than-average perforation tunnel in the casing and...
• Bilinear flowA flow regime observed in well test analysis, characteristic of hydraulically fractured wells, where fluid...
• Billion cubic feetA unit of volume for natural gas, representing one billion (1,000,000,000) cubic feet. This large unit is...
• Billion cubic feet per dayA unit of measure for the volume of natural gas produced or transported over a 24-hour period. This metric is...
• Bimetallic corrosionAn electrochemical process occurring when two dissimilar metals are in electrical contact within a corrosive...
• Bingham plastic modelA two-parameter rheological model describing a fluid that behaves as a rigid solid at low stress and flows as...
• BinsSmall, regularly spaced cells or areas on the Earth's surface into which seismic data are sorted and grouped...
• BioaccumulationThe process by which organisms absorb and retain substances, such as contaminants from drilling fluids, at a...
• BioassayA test that measures the effect of a substance, such as a drilling fluid or its components, on living...
• Biochemical oxygen demandA measure of the amount of dissolved oxygen consumed by aerobic microorganisms when decomposing organic...
• BiocideA chemical substance added to drilling fluids to control and eliminate the growth of bacteria, fungi, and...
• BioconcentrationThe uptake of a chemical substance by an aquatic organism directly from the surrounding water, leading to a...
• BiodegradationThe natural process by which microorganisms break down organic compounds into simpler substances, such as...
• BiopolymerA naturally occurring polymer, such as xanthan gum or starch, derived from living organisms and used as an...
• BiostratigraphicRelating to the use of fossils to determine the relative age of rock strata and to correlate geological...
• BiostratigraphyThe branch of stratigraphy that focuses on dating and correlating rock layers using the fossil content within...
• Biot theoryA poroelastic theory that describes the propagation of acoustic waves through a fluid-saturated porous...
• BiphasicDescribing a fluid system composed of two distinct phases, such as oil and water, gas and liquid, or two...
• BirdA remote-controlled device attached at intervals along a marine seismic streamer to maintain its position at...
• BirefringenceThe optical phenomenon in which a material splits a single incident light ray into two separate, orthogonally...
• BitThe cutting tool attached to the end of the drill string that grinds, scrapes, or shears rock to create a...
• Bit boxA sturdy steel container used to transport and store drill bits, protecting the cutting structure and threads...
• Bit breakerA heavy steel plate with a central opening and lugs that engage the drill bit's features, used to hold the...
• Bit nozzleA small, replaceable component inserted into the drill bit that directs and accelerates the flow of drilling...
• Bit recordA detailed log documenting the performance of each drill bit used to drill a well. The record includes the...
• Bit resistivityA measurement of the electrical resistivity of the formation taken by sensors located on the drilling bit or...
• Bit tripThe process of pulling the drill string out of the wellbore to replace a worn or damaged drill bit, and then...
• BitumenA viscous, black, tar-like form of petroleum that is too heavy or thick to flow easily at reservoir...
• Bivariate analysisA statistical method used in reservoir characterization to investigate the relationship between two different...
• Black listA regulatory list of chemical substances or products that are prohibited or severely restricted for use in...
• Blaine finenessA measure of the specific surface area of a finely ground material, such as cement or barite, determined by...
• Bland coring fluidA drilling fluid specifically designed to minimize alteration of the rock properties and fluid content of a...
• Blank pipeA section of casing or tubing that does not have perforations or other openings along its length. It is used...
• Blanket gasAn inert gas, such as nitrogen or natural gas, maintained in the vapor space of a storage tank or vessel to...
• Blast jointA heavy-walled, abrasion-resistant tubular component installed in a production tubing string opposite...
• Blast sleeveA replaceable protective sleeve fitted inside flow control equipment, such as a choke or valve body, at the...
• Blasting capA small, sensitive explosive device used to initiate the detonation of a larger, less sensitive explosive...
• Bleed offTo slowly release pressure from a wellbore, pipeline, or equipment by opening a valve or choke. This...
• Bleedoff lineA small-diameter pipe or hose connected to a wellbore or pressure system to safely vent or relieve excess...
• Blended crudeA mixture of two or more different crude oils, or crude oil combined with other petroleum products such as...
• BlenderA piece of surface equipment used in hydraulic fracturing operations to mix dry proppant with liquid...
• Blind boxA heavy slickline tool with a closed, blind lower end, run to hammer on an obstruction in the tubing and...
• Blind ramA type of ram in a blowout preventer (BOP) that has no opening for the drill pipe and is designed to seal off...
• Blind shear ramA component of a blowout preventer (BOP) that can seal off a wellbore by shearing through any pipe or...
• Blind zoneA subsurface region from which seismic reflections cannot be recorded or interpreted due to limitations of...
• BlockThe set of pulleys, or sheaves, that hangs from the top of the derrick (the crown block) or moves up and down...
• Block valveA valve designed to completely stop the flow of fluid in a pipeline or process system, providing positive...
• BlockageAn obstruction within a wellbore or flowline that restricts the passage of fluids, leading to reduced...
• Block-and-bleedA valve configuration that isolates a section of pipeline or equipment by closing two inline block valves and...
• Blow downTo intentionally reduce the pressure in a well or a surface system by venting fluids or gas to a flare or a...
• Blow outThe uncontrolled release of formation fluids, such as oil, gas, or water, from a wellbore to the surface...
• Blow-byThe leakage of combustion gases past the piston rings into the crankcase of an internal combustion engine, or...
• Blowdown valve (BDV)A valve designed for the rapid depressurization of a process vessel or pipeline by venting its contents to a...
• Blowing the dripThe routine of draining liquids that settle in a drip, a low-point collector on a gas pipeline or gathering...
• BlowoutThe uncontrolled flow of formation fluids, including oil, gas, or water, from a wellbore to the surface. This...
• Blowout preventerA large, specialized valve or series of valves installed at the wellhead to control wellbore pressure and...
• BLPDAn abbreviation for barrels of liquid per day, a unit of measurement for the total volume of liquid produced...
• BMAn abbreviation for Benchmark, which is a point of known elevation or position that serves as a reference for...
• BODAn abbreviation for biochemical oxygen demand, which quantifies the amount of dissolved oxygen consumed by...
• Body relief valve (BRV)A small relief valve installed on the body cavity of certain types of valves, such as ball valves, to prevent...
• Body waveA type of seismic wave that travels through the interior of a medium, such as the Earth's crust, mantle, or...
• Boltzmann probability distributionA statistical mechanics principle describing the probability of a system being in a certain state as a...
• BombA high-pressure, high-temperature (HPHT) steel cylinder used for static aging tests on drilling fluid samples...
• Bond logA wireline log that evaluates how well cement is bonded to the casing and the formation behind it, using an...
• Bond numberA dimensionless quantity representing the ratio of gravitational forces to surface tension forces. It...
• BonnetA component of a valve that houses the valve stem, packing, and other internal parts, forming a pressure...
• Bonus considerationAn upfront payment made by a lessee to a lessor as an incentive to secure an oil and gas lease. This payment...
• Boolean simulationA geostatistical modeling technique that represents geological features as discrete objects, such as channels...
• BoosterA secondary explosive device used to amplify the detonation wave from a primary initiator, such as a...
• BOPA large, specialized valve or assembly of valves installed at the top of a well, known as a Blowout...
• BOP stackAn assembly of multiple blowout preventers (BOPs) and associated control equipment, installed on the wellhead...
• BOPDAn abbreviation for barrels of oil per day, which quantifies the volume of crude oil produced from a well or...
• BoreholeThe cylindrical hole drilled into the earth by a drilling rig to explore for or produce oil and gas. Its...
• Borehole compensationA technique used in wireline logging to correct measurements for the effects of variations in borehole size...
• Borehole correctionThe process of adjusting raw logging measurements to account for the influence of the borehole environment on...
• Borehole gravityA measurement of the gravitational field within a wellbore, used to determine bulk density of the surrounding...
• Borehole gravity meterA downhole instrument that measures minute changes in the Earth's gravitational field within a borehole. It...
• Borehole orientationThe spatial direction of a wellbore, described by its azimuth and inclination relative to true north and...
• Borehole seismic dataSeismic measurements acquired by deploying seismic sensors (geophones or hydrophones) inside a wellbore...
• Borehole televiewerA logging tool that uses acoustic or optical sensors to produce an oriented, high-resolution image of the...
• Born methodA mathematical approximation used in the inversion of wave-based data, such as seismic or electromagnetic...
• Bottle testA laboratory procedure used to evaluate the effectiveness of chemical additives, such as demulsifiers or...
• Bottom log intervalThe lowest section of a wellbore for which logging data has been acquired. This interval typically extends...
• Bottom sampleA spot sample of liquid taken at or near the lowest point of a storage tank, vessel or line to show what has...
• Bottomhole assemblyThe lower section of the drill string, extending from the drill bit up to the drill pipe. This assembly...
• Bottomhole chokeA device with a restricted orifice installed in the production tubing near the bottom of the well to control...
• Bottomhole circulating temperatureThe temperature of the fluid at the base of a well after pumping has continued for some hours. Circulation...
• Bottomhole gas separatorA downhole tool installed in a wellbore to separate free gas from the liquid phase before the fluid enters...
• Bottomhole heaterA device installed near the bottom of a wellbore to heat the crude oil or other fluids, reducing their...
• Bottomhole injection pressure (BHIP)The pressure measured or calculated at the bottom of an injection well, representing the force exerted on the...
• Bottomhole pressureThe fluid pressure at the deepest point of a well, equal to the hydrostatic pressure of the fluid column plus...
• Bottomhole samplerA wireline-run tool designed to capture a sample of reservoir fluid under downhole pressure and temperature...
• Bottomhole shut-inThe closing of a valve located at the bottom of the wellbore, near the producing formation, to stop fluid...
• Bottomhole static temperatureThe temperature of the formation at the bottom of the wellbore when the well is in a static, undisturbed...
• Bottomhole temperatureThe temperature of the formation at the total depth of a well. It is a key parameter for correcting log...
• Bottoms-upThe process of circulating drilling fluid from the bottom of the wellbore to the surface, bringing with it...
• Bottoms-up mud sampleA sample of drilling fluid taken at the surface after it has circulated from the bottom of the wellbore. This...
• Bouguer anomalyThe difference between the observed gravity value at a station and the theoretical gravity value, after...
• Bouguer correctionA gravity correction applied to observed gravity measurements to account for the gravitational attraction of...
• Bouma sequenceA classic vertical succession of sedimentary structures observed in turbidite deposits, representing...
• Bound fluidThe portion of the pore fluid that is held in place by capillary forces or adsorbed on mineral surfaces and...
• Bound waterWater within a rock's pore space that is immobile due to capillary forces or adsorption to mineral surfaces...
• Boundary conditionsThe specified physical constraints or properties at the edges of a reservoir model or wellbore system...
• Bounded reservoirA reservoir that is completely enclosed by impermeable barriers or has reached a state where its outer...
• Bound-fluid logA measurement, derived primarily from nuclear magnetic resonance (NMR) tools, that quantifies the volume of...
• Bow tieA characteristic pattern observed on seismic reflection time sections, typically caused by the focusing of...
• Bow-spring centralizerA device with flexible, outwardly curved metal strips, or bows, that is attached to casing before it is run...
• BoxThe female threaded connection on a drill pipe, casing, or tubing joint, designed to receive the male pin end...
• Box plotsA graphical representation of the distribution of a dataset, displaying the median, quartiles, and potential...
• Boyle's LawA fundamental gas law stating that for a fixed amount of an ideal gas kept at a constant temperature, the...
• Boyle's Law Double CellA laboratory method for measuring the porosity of rock samples using two interconnected chambers and applying...
• Boyle's Law Single CellA laboratory technique for determining the grain volume of a rock sample by expanding a known volume of gas...
• BrachistochroneThe curve along which a particle slides under gravity between two points in the least time, an arc of a...
• Braided lineA type of wireline constructed from multiple strands of steel wire braided together, used for heavy-duty...
• BrakeA mechanical system on a drilling rig used to control the speed and position of the drawworks, which hoists...
• BreakThe first arrival of seismic energy at a geophone or hydrophone, indicating the direct wave or a refracted...
• Break circulationTo initiate the flow of drilling fluid through the wellbore after a period of static conditions, such as...
• Break outTo unscrew and separate two sections of drill pipe, casing, or tubing that were previously connected. This...
• Breakdown pressureThe minimum pressure required to initiate a fracture in a rock formation, overcoming the in-situ stresses and...
• BreakerA chemical additive used in drilling and completion fluids, particularly in fracturing operations, to reduce...
• BreakoutThe failure of the wellbore wall in the form of spalling or fracturing, often occurring in pairs on opposite...
• Breakout catheadA clutch-engaged spool on the catshaft of the drawworks, usually on the side opposite the driller, that uses...
• Breakout tongsLarge, heavy-duty wrenches used to apply torque to drill pipe, casing, or tubing connections to loosen them...
• BreakthroughThe undesirable arrival of an injected fluid, such as water or gas, at a producing well, indicating...
• BridgeAn obstruction in the wellbore that prevents the passage of tools or fluids. It can be formed by caving...
• Bridge plugA downhole tool set in a wellbore to isolate a lower section of the well from an upper section. It creates a...
• Bridge-offThe formation of a plug in a wellbore caused by solid particles, such as sand or cuttings, accumulating at a...
• Bridging agentA solid material added to drilling fluids to plug pores and fractures in the formation, thereby preventing...
• Bridging materialSolid particles added to drilling fluid to seal permeable formations and prevent fluid loss into the rock...
• BridleA length of flexible, insulated cable, commonly several tens of feet long, that links the logging cable to an...
• Briggs color cubeA color scheme that encodes three values at once as a single shade, used to display wireline log data. Each...
• Bright spotA localized high-amplitude seismic reflection anomaly that indicates the possible presence of hydrocarbons...
• BrineWater saturated or nearly saturated with dissolved salts, primarily sodium chloride, found naturally in...
• Bring in the wellTo initiate the flow of hydrocarbons from a newly completed well or to re-establish flow after an...
• British thermal unitA traditional unit of heat energy, abbreviated as Btu, defined as the quantity of heat needed to change the...
• BroachTo create an unintentional flow path for wellbore fluids to the surface outside of the primary containment of...
• Broadside arrayA configuration of electrodes or sensors in a logging tool where the transmitting and receiving elements are...
• Bromide brineA clear, solids-free completion or workover fluid made by dissolving calcium bromide, zinc bromide, or both...
• Bromocresol greenA pH indicator dye used in the titration analysis of drilling fluid alkalinity and carbonate content. It...
• Brookfield viscometerA rotational viscometer used to measure the viscosity of drilling fluids at low shear rates. It operates by...
• BrownfieldAn existing oil or gas field that is in the middle or later stages of its productive life, characterized by...
• Brownian motionThe random, erratic movement of microscopic particles suspended in a fluid, resulting from continuous...
• Brute stackA quick preliminary stack of a seismic data set made with a rough regional velocity function for normal...
• BS&WAn abbreviation for basic sediment and water, representing the percentage of non-hydrocarbon impurities...
• BTUA standard unit of energy, the British Thermal Unit (BTU), representing the quantity of heat needed to...
• Bubble countA measurement technique used in production logging to quantify the number of gas bubbles passing a specific...
• Bubble effectA phenomenon in marine seismic data caused by the oscillation of the gas bubble generated after an airgun...
• Bubble flowA multiphase flow regime in a vertical or inclined pipe where gas is dispersed as discrete bubbles within a...
• BubblepointThe pressure at which the first bubble of gas comes out of solution from a liquid hydrocarbon mixture at a...
• Bubble-tight shutoffA performance standard for a valve indicating that it provides a complete seal against flow in the closed...
• Bucking coilA secondary coil in an electromagnetic logging tool designed to cancel out or reduce unwanted signals, such...
• Bucking currentAn electrical current applied in a focused resistivity logging tool to force the main measurement current to...
• BufferA chemical additive or system of additives that resists changes in the pH of a drilling fluid when an acid or...
• Buffer solutionAn aqueous solution containing a mixture of a weak acid and its conjugate base, or a weak base and its...
• Buffered mudA drilling fluid formulated with chemical agents that resist changes in pH, maintaining it within a desired...
• Buffered solutionA fluid formulated to resist changes in its pH upon the addition of acidic or alkaline substances. In...
• Buggy vibroA self-propelled seismic vibrator mounted on a specialized off-road vehicle, designed to generate seismic...
• Buildup testA well test conducted by shutting in a producing well and monitoring the increase in bottomhole pressure over...
• Bulk modulusA measure of a substance's resistance to uniform compression from all directions, expressed as the ratio of a...
• Bulk relaxationThe nuclear magnetic resonance relaxation that a fluid undergoes by itself, away from any pore surface, set...
• Bulk volumeThe total volume occupied by a material, including both the solid particles and the void spaces between them...
• Bull plugA solid, threaded fitting used to seal the end of a pipe or a valve opening, preventing fluid flow. It has a...
• Bullet perforatingAn older method of creating communication paths between the wellbore and the reservoir by firing steel...
• BullheadTo pump fluids down a wellbore against formation pressure, forcing them into the reservoir or a specific...
• Bump the plugTo land the top cementing plug on the float collar or landing collar at the end of displacement, which stops...
• BundleA group of pipes carrying production, injection or gas lift fluids that are insulated together and kept as...
• BuoyancyThe upward force exerted by a fluid that opposes the weight of an immersed object. In well completions...
• Buoyancy methodA laboratory technique for determining the bulk density or grain density of a rock sample by measuring its...
• Burn shoeA specialized cutting tool with an abrasive or hardened edge, attached to the bottom of a washpipe or casing...
• Burn-overA well intervention technique where a larger-diameter pipe or casing is run over a smaller, stuck pipe string...
• Butt weldA type of weld that joins two pieces of metal, such as pipe sections, end-to-end without overlapping. The...
• Butterfly chartA graphical tool used to determine true formation resistivity and the diameter of invasion from...
• Butterfly valveA quarter-turn valve that uses a rotating disc, mounted on a shaft, to regulate or stop fluid flow. When the...
• Button resistivityA high-resolution resistivity measurement obtained from small, closely spaced electrodes mounted on pads that...
• Buttress threadA type of pipe thread characterized by a flat-topped, asymmetrical profile with one flank perpendicular to...
• BWOBAn abbreviation for "by weight of blend," indicating the concentration of an additive as a percentage of the...
• BWOCAn abbreviation for "by weight of cement," a common unit of measure for additives in cement slurries. This...
• BWOWAn abbreviation for "by weight of water," a unit of measure for additives in drilling fluids or cement...
• BWPDAn abbreviation for barrels of water per day, a unit of measure for the volume of water produced from an oil...
• By weight of blendA method of expressing the concentration of an additive within a dry mixture, calculated as a percentage of...
• By weight of cementA standard unit of measure for solid additives in cement slurries, expressed as a percentage of the dry...
• By weight of waterA concentration measurement for additives in drilling fluids, expressed as a percentage of the weight of the...
• BypassA secondary flow path that allows fluid to circumvent a primary component or section of a drilling fluid...
• Bypass velocityThe velocity of fluid that flows around a downhole logging tool rather than through its measurement section...
• Bypassed mudDrilling mud left in the annulus behind a casing or liner after cementing because the cement slurry flowed...

292 of 4,469 terms in Oil and gas terminology (MLC-0103). Request the full dataset.