Oil and Gas Terms Beginning with “B” — Page 8

What Is a Bottomhole Assembly? A bottomhole assembly (BHA) is the lower section of the drillstring — the assembly of drill collars, stabilisers, measurement tools, and the drill bit that directly contacts the formation… Read more →

What Is a Bottomhole Choke? Bottomhole choke (also called a downhole choke or subsurface choke) is a fixed or adjustable flow restriction device installed in the production tubing string at or near the perforations —… Read more →

What Is Bottomhole Circulating Temperature (BHCT)? Bottomhole circulating temperature (BHCT) (also called circulating bottom-hole temperature or dynamic bottomhole temperature) is the maximum temperature measured or… Read more →

(noun) A downhole device installed below or as part of the artificial lift system that separates free gas from the produced liquid before it enters the pump intake, reducing gas interference and improving pump… Read more →

What Is a Bottomhole Heater? Bottomhole heater (also called a downhole heater or wellbore heater ) is an electrical or chemical heat-generating device installed at or near the producing interval of a well to raise the… Read more →

What Is Bottomhole Injection Pressure (BHIP)? Bottomhole injection pressure (BHIP) (also called downhole injection pressure or formation face pressure) is the actual fluid pressure measured or calculated at the… Read more →

What Is Bottomhole Pressure? Bottomhole pressure (BHP) is the fluid pressure at the bottom of a wellbore — the combined pressure of the fluid column in the well (drilling mud, completion fluid, or reservoir fluid) plus… Read more →

What Is a Bottomhole Sampler? Bottomhole sampler (also called a downhole fluid sampler or PVT sampler) is a wireline- or tubing-conveyed tool that collects a representative sample of reservoir fluid — oil, gas, or gas… Read more →

What Is Bottomhole Shut-In Pressure? Bottomhole shut-in pressure (BHSIP) (also called static bottomhole pressure or shut-in bottomhole pressure ) is the stabilized reservoir pressure measured at the perforations or… Read more →

A well shut in slightly above the producing formation by use of special downhole tools containing a valve that can be preprogrammed or controlled from the surface. This practice is commonly associated with drillstem… Read more →

What Is Bottomhole Static Temperature (BHST)? Bottomhole static temperature (BHST) (also called formation temperature or geothermal temperature at depth) is the undisturbed thermal equilibrium temperature of the… Read more →

What Is Bottomhole Temperature? Bottomhole temperature (BHT) (also called bottom hole temperature or maximum recorded temperature ) is the temperature measured by a maximum-reading thermometer mounted on a wireline… Read more →

What Is Bottoms-Up? Bottoms-up (also written as bottoms up or called lag time ) in drilling operations refers to the elapsed time or stroke count required to circulate drilling fluid from the bit at total depth to the… Read more →

What Is a Bottoms-Up Mud Sample? Bottoms-up mud sample (also called a lag sample or BU sample ) is a drilling fluid sample collected at the shale shaker after one complete annular circulation from a specific depth —… Read more →

Pertaining to the mud and cuttings that are calculated or measured to come from the bottom of the hole since the start of circulation. Circulation may be initiated after a static period, such as a trip, or from a given… Read more →

A sample of mud from the deepest or current drilling depth of a well. The term refers particularly to a mud sample that has experienced stagnant conditions at the bottom of the hole, including the temperature, pressure… Read more →

What Is Bound Fluid? Bound fluid (also called bound fluid volume or BFV ) is reservoir pore water — and occasionally oil — held immobile in the pore space by capillary forces in small pore throats or by surface… Read more →

What Is Bound Water? Bound water (also called irreducible water or non-producible water ) in formation evaluation is water held immobile in reservoir rock by two distinct mechanisms: surface adsorption onto clay mineral… Read more →

What Is a Bound Fluid Log? Bound fluid log (also called a BFV log or bound water log) is a nuclear magnetic resonance (NMR) log-derived product that displays the volume of pore fluid held immobile by capillary and… Read more →

The flux (flow rate) or pressure states assigned to the theoretical boundaries used in developing and solving the differential equations that apply to well testing and in specifying a model to match to… Read more →

What Is a Bounded Reservoir? Bounded reservoir (also called a volumetrically closed reservoir or finite reservoir) is a reservoir with finite areal extent where all outer boundaries are no-flow barriers — sealing… Read more →

A concave-upward event in seismic data produced by a buried focus and corrected by proper migration of seismic data. The focusing of the seismic wave produces three reflection points on the event per surface location.… Read more →

What Is a Bow-Spring Centralizer? Bow-spring centralizer (also called a spring bow centralizer or flexible centralizer) is a casing centralization device consisting of curved steel bow-springs formed or welded between… Read more →

Relating to the female threadform, as in "box end of the pipe." Read more →

A grid pattern laid over a representation of fractures. The number of boxes that contain a fracture is counted and plotted against the box size on logarithmic scales. The slope of the line is equal to minus the fractal… Read more →

What Is Braided Line? Braided line (also called wireline cable or electric line in most oilfield contexts) is a multi-strand metallic wireline cable used in oilfield well intervention and formation evaluation… Read more →

To apply the brake to slow the motion of the drawworks, and hence the drilling line and the drillstring. Read more →

What Is Break Circulation? Break circulation (also called breaking circulation or initiating circulation ) is the act of restarting drilling fluid flow through a drill string that has been static — pumping mud again… Read more →

What Is Break-Out (Pipe)? Break-out (also called breaking out or backing off a connection) is the rig floor operation of unscrewing a threaded tubular joint — drill pipe, drill collar, or casing — by applying reverse… Read more →

What Is Breakdown Pressure? Breakdown pressure is the wellbore pressure at which a hydraulic fracture initiates in the formation — the point during a hydraulic fracturing treatment or leak-off test (LOT) when the… Read more →