Glossary

1. bottom of; used in drilling reports. 2. center of buoyancy; used mostly in making buoyancy, stability, and trim calculations for offshore drilling rigs. 3. formation volume factor. 4. shear modulus, psi/radian.

a liquefied hydrocarbon product composed chiefly of butanes and propane. If it originates from a refinery, it may also contain butylenes and propylene.

barrels per day; often used in drilling reports.

barrels per day.

metal alloy, either tin-based or lead-based, used primarily in friction bearings.

1. voltage induced in the primary winding of a transformer that opposes the incoming line voltage. 2. voltage induced in the armature of a motor by the magnetic field in which it is turning. Also called counter emf and counter-voltage. See electromotive force.

back electromotive force.

to unscrew one threaded piece (such as a section of pipe) from another.

in a PDC bit, the amount of distance, in degrees, between vertical (90°) and the face of the cutter.

to enlarge the wellbore by raising and rotating the drill string that has a reamer made up in it. Back reaming enlarges tight spots in the wellbore. See reaming.

to hold one section of an object such as pipe while another section is being screwed into or out of it.

an option right reserved by the granting company of a farmout to convert an overriding royalty to a working interest once the conditions for such back-in have been met. Compare election at casing point.

a portable servicing or workover rig that is self-propelled, using the hoisting engines for motive power. Because the driver’s cab is mounted on the end opposite the mast support, the unit must be backed up to the wellhead. See carrier rig, drive-in unit.

the procedure whereby one threaded piece (such as a pipe) is unscrewed from another.

see washover back-off connector.

a section of pipe with left-hand threads on one end and conventional right-hand threads on the other. In setting a liner, a back-off joint is attached to it so that the drill pipe may be disengaged from the liner by conventional right-hand rotation.

see wheel-type back-off wrench.

1. the pressure maintained on equipment or systems through which a fluid flows. 2. in reference to engines, a term used to describe the resistance to the flow of exhaust gas through the exhaust pipe. 3. the operating pressure level measured downstream from a measuring device.

a pneumatically operated device-a controller-which maintains a fixed pressure by controlling the amount of upstream pressure on a vessel such as a fractionating tower or an oil and gas separator.

a device that reduces or increases upstream, or back-pressure to maintain a given amount of back-pressure in a pneumatic line.

1. a valve used to regulate back-pressure on equipment or systems through which a fluid flows. 2. a valve used to regulate automatically a uniform pressure on the inlet side of the valve.

the depositional environments associated with a shallow lagoon shoreward from a coastal barrier island. These environments are highly variable and may include tidal channels, salt marshes, shell reefs, and mangrove swamps, among others.

the technique for covering a completed pipeline so that adequate fill material is provided underneath the pipe as well as above it. Backfilling prevents pipe damage caused by loose rock, abrasion, shifting, and washouts.

in drilling operations, gas that returns to the surface with the drilling mud in measurable quantities but does not cause a kick. Increases in background gas may indicate that the well is about to kick or has kicked.

a transport of gas by displacement against the flow on a single pipeline, so that the gas is redelivered upstream of its point of receipt.

an excavating machine fitted with a hinged arm to which is rigidly attached a bucket that is drawn toward the machine in operation. The backhoe is used for excavating and for clearing blasted rock out of the ditch during ditching and pipe laying.

to overcome the positive electrical potentials of anodic areas in cathodic protection systems.

see back ream.

that part of the seashore that lies between high-tide and storm-flood level.

the area above a packer between casing ID and tubing OD.

a metal sealing ring on either side of the center packing element of an annular blowout preventer to limit the packer’s extrusion.

a cylindrical ring employed to back up (or assist) a sealing member against extrusion under temperature and pressure.

a set of devices in an assembly or in a process that can take over the operation of the assembly or process should the devices normally used to operate the assembly or process fail.

the tongs latched on the drill pipe joint hanging in the rotary by the slips, used to keep the pipe from turning as the makeup or breakout tongs (the lead tongs) apply torque to make up or break out the tightened tool joint connection. Compare lead tongs.

any wrench used to hold a pipe or a bolt to prevent its turning while another length of pipe or a nut is being screwed into or out of it.

to reverse the flow of fluid from a water injection well to get rid of sediment that has clogged the wellbore.

best-available control technology.

a large, widely distributed group of typically one-celled microorganisms. See anaerobic bacteria, sulfate-reducing bacteria.

anything that destroys bacteria.

oil that contains a sufficient amount of sediment and water to make it unacceptable to a pipeline or other oil transportation system.

1. a partial restriction, generally a plate, placed to change the direction, guide the flow, or promote mixing within a tank or a vessel. 2. a device that is seated on the bit pin, in a tool joint, or in a drill pipe float, to centralize the lower end of a go-devil while permitting the bypass of drilling fluid. The go-devil contains a surveying instrument.

devices that regulate the flow of fluids. In a mixing tank, baffles are needed to stop the swirl using impellers that rotate clockwise or counterclockwise.

on an engine, a bag-shaped piece made of cotton or fiber cloth that fits into a special holder in the fuel system piping. Fuel is circulated through the bag, which removes foreign matter from the fuel.

a tropical cyclone in the Philippines. Also called baruio.

brazed aluminum heat exchanger.

1. a cylindrical steel bar (similar to the handle or bail of a bucket, only much larger) that supports the swivel and connects it to the hook. Sometimes, the two cylindrical bars that support the elevators and attach them to the hook are called bails or links. 2. the U-shaped handle on a nozzle used to close a valve that shuts off water flow when pushed forward. v: to recover bottomhole fluids, samples, or drill cuttings by lowering a cylindrical vessel called a bailer to the bottom of a well, filling it, and retrieving it.

a large steel dowel (pin) that attaches the swivel’s bail to the swivel’s body. Normally, swivels have two bail pins, one for each side of the bail where it attaches to the body. See bail.

the inside curve in the swivel’s bail where the bail hangs from the traveling block’s hook. See bail.

a long, cylindrical container fitted with a valve at its lower end, used to remove water, sand, mud, drilling cuttings, or oil from a well in cable-tool drilling.

the operation of cleaning mud cuttings and other material from the bottom of the wellbore with a bailer.

the reel around which the bailing line is wound. See bailing line.

the cable attached to a bailer, passed over a sheave at the top of the derrick, and spooled on a reel.

a gas supply mechanism that might range from a common scuba bottle fitted with a regulator and hose connected to a valve on the helmet to a complex closed-circuit system used in very deep water. Also called divers emergency gas supply.

the point at which enough pipe has been snubbed into the hole to allow the pipe’s weight to overcome the upward force of well pressure. See snubbing, stripping in.

when the pressure of drilling fluid in the wellbore is the same as the pressure in the formation.

the displacement of enough cement out of the drill pipe to achieve a column of cement in both pipe and annulus that are equal in height.

a type of chain-connecting link manufactured by Baldt.

a spherical object that, when pumped down the hole, operates certain hydraulic tools.

a bearing in which a finely machined shaft (a journal) turns on freely rotating hardened-steel spheres that roll easily within a groove or track (a race) and thus convert sliding friction into rolling friction. See ball race.

a cylindrical tube placed around the retrieving neck of a retrievable bridge plug to catch debris or frac balls.

a device for regulating the level of fluid in a tank. It consists of a valve connected to a hollow floating ball that, by rising or falling, shuts or opens the valve.

in drilling from floating offshore drilling rigs that employ a subsea blowout preventer system, a device mounted between the annular preventer and the riser adapter on the lower marine riser package (LMRP) to prevent excessive bending forces from being exerted on the marine riser, the LMRP, and the blowout preventer components. It is a forged-steel ball and socket containing a cylindrical neck extension with a riser adapter attached at the top of the neck. Compare flex joint.

a hollow drum that contains material to be ground or pulverized, heavy steel or ceramic balls, and a liquid such as water. The drum is rolled or agitated so that the balls crush or polish the material as they roll about.

a track, channel, or groove in which ball bearings turn.

balls made of nylon, hard rubber, or both and used to shut off perforations through which excessive fluid is being lost.

1. to collect a mass of sticky consolidated material, usually drill cuttings, on drill pipe, drill collars, bits, and so forth. A bit with such material attached to it is called a balled-up bit. Balling up is frequently the result of inadequate pump pressure or insufficient drilling fluid. 2. in reference to an anchor, to fail to hold on a soft bottom, pulling out, instead, with a large ball of mud attached.

a flow-control device employing a ball with a rotating mechanism to open or close the tubing.

a device used to restrict fluid flow to one direction. It consists of a polished sphere, or ball, usually of metal, and an annular piece, the seat, ground and polished to form a seal with the surface of the ball. Gravitational force or the force of a spring holds the ball against the seat. Flow in the direction of the force is prevented, while flow in the opposite direction overcomes the force and unseats the ball.

to use a ball mill to grind, polish, or pulverize metal or stone particles.

to plug open perforations by using ball sealers.

1. for ships, water taken on board into specific tanks to permit proper angle of repose of the vessel in the water, and to assure structural stability. 2. for semisubmersible drilling rigs, seawater added to the rig’s pontoons to increase its draft, or to submerge it to a desired depth below the sea’s surface.

the act of maintaining a floating offshore drilling rig on even keel, regardless of weather or load conditions.

on a semisubmersible drilling rig, the person responsible for maintaining the rig’s stability under all weather and load conditions.

see ballast movement.

a voyage or voyage leg made without any paying cargo in the vessel’s tanks. To maintain proper stability, trim, or draft, seawater is usually carried during such movements. Also called ballast leg or ballast passage.

see ballast movement.

any shipboard tank or tanker compartment normally used for carrying saltwater ballast. When these compartments or tanks are not connected with the cargo system, they are called segregated ballast tanks or systems.

the condition of a floating offshore drilling rig when ballast has been added.

see ballast

see ball up.

see small-volume prover.

to swell or puff up. In reference to tubing under the effects of temperature changes, sucker rod pumping, or high internal pressure, to increase in diameter while decreasing in length. Compare reverse-balloon.

a thin sheet of steel created when a washover pipe’s rotary shoe grinds into the casing and mills a portion of the casing. It can be prevented by selecting a shoe diameter that is much smaller than the diameter of the casing but is still of adequate diameter to remove the material that is sticking the fish.

on offshore installations that have grated flooring or decks, a length of flat metal welded to the side or end of a panel of grating or to the edges of a cutout section of grating, that does not extend above or below the bearing bars, which are the steel or aluminum bars that support the grating.

circular type of brake either of external contracting type or internal expanding type, having a strap lined with heat and wear resistant friction material.

circular type of clutch either of external contracting type or internal expanding type, having a strap lined with heat and wear resistant friction material.

see draft.

a unit of pressure equal to 100,000 pascals, 100,00 newtons per square metre, or 1 million dynes per square centimetre. v: to move or turn (as a flywheel) with a bar used as a lever.

a piece of hard steel in the shape of a rectangular-shaped rod (a bar) that has been strongly magnetized and holds its magnetism. It is therefore a type of permanent magnet. See permanent magnet.

reservoir rock formed from a mass of sand, gravel, or alluvium deposited on the bed of a stream, sea, or lake by waves and currents.

an agreement to lease, or charter, a ship or offshore drilling unit without crew or equipment, usually for a predetermined time.

see open-hole completion.

1. a flat-decked, shallow-draft vessel, usually towed or pushed by a tugboat. Barges are not self-propelled. They are used to transport oil or products on rivers, lakes, and inland waterways. Also, a complete drilling rig may be assembled on a barge and the vessel used for drilling wells in lakes and in inland waters and marshes. Similarly, well service and workover equipment can be mounted on a barge. 2. a drill barge. See drill barge.

an employee on a semisubmersible rig whose main duty is to monitor and control the stability of the rig. From a special work station on board the rig, this person controls the placement of ballast water inside the rig’s pontoons to maintain the rig on even keel during all operations.

see barge control operator.

see barge control operator.

a string of barges laced together with ratchets and steel cable.

on offshore rigs, the personnel on the rig who are concerned with its buoyancy and stability characteristics. They are responsible for keeping track of factors that affect the rig’s stability and for taking the required corrective measures to ensure that the rig maintains its stability.

see Buys-Ballot’s law.

barium sulfate, BaSO4; a mineral frequently used to increase the weight or density of drilling mud. Its relative density is 4.2 (i.e., it is 4.2 times denser than water). See barium sulfate, mud.

a settled volume of barite particles from a barite slurry placed in the wellbore to seal off a pressured zone.

a container (a sack) of powdery material (barite) that weighs about 100 pounds (about 45 kilograms). Barite is a dense mineral with a specific gravity of about 4.2-it is over four times heavier than water. On drilling rigs, barite (barium sulfate, or BaSO4) can be supplied in heavy-duty paper sacks. In drilling from floating drilling rigs, sacks of barite are sometimes placed on top of the temporary guide base before it is run to the seafloor. The sacks provide additional weight to the guide base and ensure that it makes firm contact with the seafloor. Also, barite is often used to increase the density, or weight, of drilling mud. See barite, temporary guide base.

a mixture of barium sulfate, chemicals, and water of a unit density between 18 and 22 pounds per gallon.

a chemical compound of barium, sulfur, and oxygen (BaSO4), which may form a tenacious scale that is very difficult to remove. Also called barite. See barite.

an aneroid barometer that continuously records atmospheric pressure values on a graph or chart.

an instrument for measuring atmospheric pressure. See aneroid barometer, mercury barometer.

see atmospheric pressure.

1. a measure of volume for petroleum products in the United States. One barrel is the equivalent of 42 U.S. gallons or 0.15899 cubic metres (9,702 cubic inches). One cubic metre equals 6.2897 barrels. 2. the cylindrical part of a sucker rod pump in which the pistonlike plunger moves up and down. Operating as a piston inside a cylinder, the plunger and barrel create pressure energy to lift well fluids to the surface. 3. the lagging or body portion of a rope drum.

a special type of centrifugal compressor with a barrel-shaped housing.

a laboratory unit used for evaluating or testing drilling fluids. One gram of material, when added to 350 millilitres of fluid, is equivalent to 1 pound of material added to one 42-gallon barrel of fluid.

in pipeline construction, a cylindrical device fitted on both ends with hollow cutting teeth, used in directionally drilled river crossings. Used during the pullback portion of a crossing effort, the barrel reamer opens the hole and keeps the pull on course.

a unit of measure for pipeline shipment of oil or liquid product that signifies 1 barrel moved 1 mile.

in the United States, a measure of the rate of flow of a well; the total amount of oil and other fluids produced or processed per day.

in well control and under­balanced drilling, a means of preventing the uncontrolled flow of fluids from a well. Barriers range from drilling mud whose hydrostatic pressure is greater than formation pressure to mechanical devices such as blowout preventers and drill stem valves, which, when closed, prevent the exit of fluids from the well.

turning over an engine by hand. A solid-steel rod (a bar) is inserted into special holes in the engine’s flywheel. By lifting up or pressing down on the bar, the flywheel can be turned, which rotates the pistons in the cylinders. Barring is used as a precautionary measure before starting an engine that has not been run in some time.

see baguio.

variation of barite. See barite.

an extrusive igneous rock that is dense, fine grained, and often dark gray to black. Compare gabbro.

1. a substance capable of reacting with an acid to form a salt. A typical base is sodium hydroxide (caustic), with the chemical formula NaOH. For example, sodium hydroxide combines with hydrochloric acid to form sodium chloride (a salt) and water. This reaction is written chemically as NaOH + HCl →  NaCl + H2O. 2. in a junction transistor, the region that lies between the transistor’s emitter and collector and into which minority carriers are injected. The base is the transistor’s control terminal and receives current from an external source into its region. See collector, emitter.

the pedestal upon which the revolving superstructure is mounted.

an abstract of title that contains full and complete copies of all recorded instruments from the sovereignty of the soil to the date the same is completed as set forth in the abstractor’s certificate.

the replacement of cations associated with a clay surface by those of another element, e.g., the conversion of sodium clay to calcium clay.

the volume of gas needed as permanent inventory to maintain adequate underground storage reservoir pressures and deliverability rates throughout the withdrawal season.

1. the fore and aft reference line at the upper surface of the flat plate keel at the center line for flush shell plate vessels. 2. the thickness of the garboard strake above that level for vessels having lap seam shell plating.

as applied to gas, a given send-out of gas remaining fairly constant over a period of time and usually not temperature sensitive. For example, residential base load is a given send-out of gas consumed by clothes dryers, water heaters, and in cooking.

horizontal representation of nongeologic surface features such as streams, roads, buildings, survey benchmarks, and property lines.

1. any of the reactive metals at the lower end of the electrochemical series. 2. metal to which cladding or plating is applied.

1. in drilling from floating rigs, a flat steel piece (a plate) that is part of the riser-support spider (the device that supports riser pipe in the rotary table as it is being run or retrieved). The base plate supports the spider and fits into the rig’s rotary table. 2. in drilling from floating rigs, a flat steel piece (a plate) at the top of the lower marine riser package (LMRP) on top of which the control pods are attached and which supports the pods on the LMRP. See lower marine riser package, riser-support spider.

the pressure exerted by a specific number of molecules contained in a specific volume (usually 1 cubic foot) at a specific temperature. Base pressure is a factor used in calculating gas volume. Standard base pressure varies from state to state. In Texas, for example, base pressure is 14.73 psia at 60°F. In Louisiana, base pressure is 15.025 psia at 60°F.

the value of natural gas, usually at the wellhead, before any imposition of taxes, gathering, compression, or other charges, as stated in a gas sales contract.

one of a small number of physical quantities in a system of measurement that is defined, independent of other physical quantities, by means of a physical standard and by procedures for comparing the quantity to be measured with the standard. Also known as fundamental quantity.

see basement rock.

igneous or metamorphic rock, which seldom contains petroleum. Ordinarily, it lies below sedimentary rock. When it is encountered in drilling, the well is usually abandoned.

see sediment.

the water and other extraneous material present in crude oil. Usually this content must be acceptably low for a pipeline or other shipper to accept the oil for delivery to a refinery. The amount acceptable depends on a number of factors but usually runs from less than 5 percent to a small fraction of 1 percent. See sediment and water (S&W).

pH value above 7 and the ability to neutralize or accept protons from acids.

1. a local depression in the earth’s crust in which sediments can accumulate to form thick sequences of sedimentary rock. 2. the area drained by a stream and its tributaries. 3. a geologic structure in which strata are inclined toward a common center.

a device placed in the drill or work string that catches debris when a drillable object is being milled or drilled downhole.

an expandable, cylindrically shaped gripping mechanism that is fitted into an overshot to retrieve fish from the borehole. See grapple.

in crane operations, a method of attaching a sling to a load in which both ends of the sling are passed under the load and then attached to the crane’s hook.

a fishing accessory run above a bit or a mill to recover small, non­drill-able pieces of metal or junk in a well.

1. a specific quantity of material that is processed, treated, or used in one operation. 2. in corrosion control, a quan- tity of chemical corrosion inhibitors in- jected into the lines of a production system. 3. in oilwell cementing, a part of the total quantity of cement to be used in a well. 4. in pipelining, a quantity of one weight or type of crude or liquid product pumped next to one of different weight or type.

in oilwell cementing, the pumping of cement in partial amounts, or batches, as contrasted with pumping it all in one operation.

a cement-mixing system in which dry cement and water are blended by a stream of air. The primary disadvantages are uneven mixing and volume limitations.

the process by which a single quantity of crude oil emulsion is broken into oil and water. The emulsion is gathered and stored in a tank or container prior to treating. Compare flow-line treating.

in corrosion control, the injection of a quantity of chemical corrosion inhibitors into the lines of a production system, usually on a regular schedule.

in pipelining, the pumping of a quantity of crude or product of one weight next to one of different weight or type. Usually, a small amount of mixing occurs where the two batches come in contact.

a large rubber ball placed in a pipeline to separate batches and prevent mixing.

liquid placed in a container and held at a controlled temperature to regulate the temperature of any system placed in it or passing through it.

cathodic potential probes used to measure the deterioration of steel structures under water. The meter measures the electrochemical potential of the steel structure against a silver-silver chloride reference cell. The information determines whether there is sufficient cathodic protection present on the structure, usually in the form of sacrificial anodes.

seafloor conditions (e.g., contours or anomalies).

1. an installation of identical or nearly identical pieces of equipment (such as a tank battery or a battery of meters). 2. an electricity storage device consisting of two or more galvanic cells. See galvanic cell.

an electrical device (a rectifier) that converts alternating current into direct current and is used to reestablish the battery’s ability to produce current by reversing the chemical reaction that occurs in a secondary (wet cell) battery when it discharges. See rectifier.

in digital communication terminology, a unit of speed in data transmission equal to one bit per second.

specific gravity as measured by the Baumé scale. Two arbitrary scales are employed: one for liquids lighter than water and the other for liquids heavier than water. This scale is also used to describe the density of acid solutions.

either of two arbitrary scales-one for liquids lighter than water and the other for liquids heavier than water-that indicates specific gravity in degrees.

an ore that is the main source of aluminum. It may be white, gray, brown, yellow, or reddish brown and is composed of aluminum oxides and aluminum hydroxides. It often contains impurities such as silt, silica, iron hydroxides, and clays.

barrel.

barrels per acre-foot.

barrels per day.

Bearden units of consistency-dimensionless.

binary coded decimal.

billion cubic feet.

billion cubic feet per day.

bottom dead center.

slope of flowmeter velocity vs rps response curve (down runs).

1. the extreme width (breadth) of the hull of a ship or mobile offshore drilling rig. 2. a walking beam. See walking beam.

the weights on a beam pumping unit installed on the end of the walking beam, which is opposite the end over the well. The counterbalance offsets, or balances, the weight of sucker rods and other downhole equipment installed in the well.

see beam pumping unit.

beam pumping is commonly used on-land artificial lift method for petroleum production. See beam pumping unit.

a machine designed specifically for sucker rod pumping. An engine or motor (prime mover) is mounted on the unit to power a rotating crank. The crank moves a horizontal member (walking beam) up and down to produce reciprocating motion. This reciprocating motion operates the pump. Compare pump jack.

a well whose fluid is being lifted by rods and pump actuated by a beam pumping unit.

a beam pumping unit that has a counterbalance weight on the walking beam.

a nipple or restriction placed in a line (a pipe) to reduce the rate of flow of fluid through the line. Beans are frequently placed in Christmas trees to regulate the flow of fluids coming out of the well. Also called a flow bean. See Christmas tree.

the thickness, or viscosity, of a slurry (a liquid in which solid particles are suspended), measured in terms of a unit developed by an engineer named Bearden. (Cement particles suspended in water is a common oilfield slurry.) Bearden units of consistency are dimensionless-that is, such units can only be compared to each other when expressing a slurry’s consistency. Therefore, Bearden units cannot be converted to other units of viscosity.

1. an object, surface, or point that supports. 2. a machine part in which another part (such as a journal or pin) turns or slides.

in a machine, any device consisting of a set of bearings on or against which two or more surfaces move. The assembly holds the bearings in place as the surfaces move.

on offshore installations with grated floors or decks, load carrying bars made from steel strips or from rolled or extruded aluminum and extending in the direction of the grating span.

a device that is fitted around a bearing to hold or immobilize it.

a machined extension around which are placed bit bearings.

a numerical ranking system that provides an estimate of the force of wind and the height of waves. Higher-scale values correlate with higher forces.

a specific layer of earth or rock that presents a contrast to other layers of different material lying above, below, or adjacent to it.

the gravel and coarse sand that are rolled and bounced along the bottom of a flowing stream. Compare dissolved load, suspended load.

the surface that separates each successive layer of a stratified rock from the preceding layer. It is here that minor changes in sediments or depositional conditions can be observed.

solid rock just beneath the soil.

slang. See flow by heads.

an enclosed compartment, pressurized (closed bell) or un-pressurized (open bell), which allows the diver to be transported to and from the underwater work area and which may be used as a temporary refuge during diving operations. A Class-I bell is a closed bell. A Class-II bell is an open-bottom bell. v: to flare the end of a cylindrical object so that it resembles the bottom of a bell.

method of diving that uses a large underwater work vessel that is open on the bottom and is supplied with air under pressure.

a hole shaped like a bell, larger at the top than at the bottom. A bell hole may be dug beneath a pipeline to allow access for workers and tools.

the standby diver during closed-bell diving operations.

a short length of pipe (a nipple) installed on top of the blowout preventer. The top end of the nipple is flared, or belled, to guide drill tools into the hole and usually has side connections for the fill line and mud return line.

a tool joint box which has been subjected to a torque which has resulted in permanent enlargement of the box diameter. This normally occurs adjacent to the box sealing shoulder.

a pressure-sensing element of cylindrical shape whose walls contain convolutions that cause the length of the bellows to change when pressure is applied.

see orifice meter.

a flexible band or cord connecting and wrapping around each of two or more pulleys to transmit power or impart motion.

a protective grill or cover for a belt and pulleys.

a marking on the pin and the box of a tool joint that gauges the amount of metal that can be safely removed when dressing (facing) the pin or box shoulder.

the price per barrel of certain crude oils such as West Texas intermediate and North Sea Brent, which serves as an indicator of worldwide oil prices.

occurs when tension is increased on one side of the pipe while compression is increased on the other.

the force created on an object by applying the weight of another object so that the weight bends or tends to bend the first object.

an attachment that keeps large-diameter pipe from buckling or wrinkling when it is bent.

a force that lateral movement (bending) creates on an object.

an attachment that works off the side-boom tractor and winch and bends small-diameter pipe.

in offshore drilling from floating rigs, a force placed on a marine riser system and subsea blowout preventer stack that originates from movements of the water and from the weight of the upper components. Wind, waves, and currents act on the equipment to cause it to bend as does the weight of components in the system.

the brand name for a type of friction clutch in an electric starter for small engines. When electric current is applied to the starter, the friction clutch (the Bendix) moves forward to engage a pinion gear on the starter with a ring gear on the engine flywheel. As the starter’s pinion rotates, it rotates the ring gear, which moves the flywheel to turn the engine over.

a highly painful and potentially fatal condition in which air or other breathable gases come out of solution in the bloodstream and cause distress or death. So named because the bending joints of the body are most often affected. Also called decompression sickness. See decompression sickness.

a special housing for the positive-displacement downhole mud motor, which is manufactured with a bend of 1˚ to 3˚ to facilitate directional drilling. A bent housing is sometimes used with the bent sub to make a drilling motor deflect more abruptly.

a short cylindrical device installed in the drill stem between the bottommost drill collar and a downhole motor. Its purpose is to deflect the downhole motor off vertical to drill a directional hole. See drill stem.

a colloidal clay, composed primarily of montmorillonite, that swells when wet. Because of its gel-forming properties, bentonite is a major component of water-base drilling muds. See gel, mud.

a group of polymers that can maintain or increase the viscosity of bentonite while flocculating other clay solids in the mud. With bentonite extenders, desired viscosity can often be maintained using only half the amount of bentonite that would otherwise be required.

C6H6, colorless, volatile, flammable toxic liquid aromatic hydrocarbon used as a solvent and as a motor fuel.

the structural arrangement of atoms believed to exist in benzene.

to make a gift of personal property by means of a will. Compare devise.

an unscientific term for a small iceberg.

a mathematical expression of the conservation of energy in streamline flow; the theorem states that the sum of the ratio of the pressure to the mass density, the product of the gravitational constant and the vertical height, and the square of the velocity divided by 2 are constant.

an air emission standard of technology determined by the states on a case-by-case basis. The BACT is applied in attainment areas that meet or exceed NAAQS, and states can consider cost and economic impact when determining exactly what the BACT is and how it will be applied in a specific case.

a factor used in calculating the amount of fluid flowing through a measurement system that employs an orifice plate. It is the ratio of the orifice’s diameter to the pipe’s diameter.

one of the extremely small particles, sometimes called rays, emitted from the nucleus of a radioactive substance such as radium or uranium as it disintegrates. Beta particles have a negative charge.

measure of the relationship of the size of the pipe through which fluid is flowing and the size of a restriction, such as an orifice.

one of a pair of toothed wheels whose working surfaces are inclined to nonparallel axes.

barrels of fluid per hour; used in drilling reports.

bottomhole assembly.

bit hydraulic horsepower.

brake horsepower.

bottomhole pressure.

bottomhole temperature.

direct-current voltage applied to a transistor control electrode to establish a desired operating point.

see directional drilling.

built-in breathing system.

see sodium bicarbonate.

a meter that can measure flow from either direction.

the first cross-country pipeline with a 24-inch (61-centimetre) diameter. The 1,340-mile (2,157-kilometre) Big Inch was begun in 1942 with government financing as a part of an emergency construction program (War Emergency Pipelines) to meet the demand for petroleum products during World War II.

thin-walled pipe of high tensile strength with a diameter of 20 inches (51 centimetres) or more.

the radius of the rounded portion of a vessel’s shell that connects the bottom to the sides.

see damage stability.

a document by which the master of a ship acknowledges having received in good order and condition (or the reverse) certain specified goods consigned by a particular shipper, and binds himself or herself to deliver them in similar condition, unless the perils of the sea, fire, or enemies prevent it, to the consignees of the shippers at the point of destination on their paying the stipulated freight.

a solid steel cylinder used to produce seamless casing. The billet is pierced lengthwise to form a hollow tube that is shaped and sized to produce the casing.

a temperature sensing and measuring device that has two strips of metal, one with an extremely low coefficient of thermal expansion and the other a rather high coefficient. Temperature is inferred from the different expansion rates of the two metals.

two metals with different thermal coefficients of expansion-one with a low coefficient and the other with high coefficient of expansion-held together through brazing, welding, or riveting, for the purpose of bending into an arc. When subjected to temperature variations, the bimetallic elements can be used for actuation, indication, and control.

1. characterized by or consisting of two parts or components; twofold. 2. of or relating to a system of numeration having 2 as its base. In instrumentation, a binary device or signal has two discrete states or conditions. For example, an on-off switch, or a voltage or current switching on and off over time are binary devices. A binary number uses two symbols, 1 and 0, that represent two discrete states or conditions; in specific combinations, the 1s and 0s can represent equivalent decimal numbers.

a system of number representation in which a binary number represents each digit of a decimal number.

a method of representing numbers using only the digits 0 and 1 in which successive digits are interpreted as coefficients of successive powers to the base 2. For example, the decimal number 3 is 10 in binary numbers and the decimal number 4 is 11 in binary numbers.

the character, or the location of an implied symbol, that separates the integral part of the numerical expression from its fractional part in binary notation.

a substance that, when added to a collection of loose substances, causes the loose substances to cohere.

a steel bar or section fixed to the edges of a panel of deck grating on an offshore installation that is flush with the top of the grating supports.

a non-Newtonian fluid that has a given yield stress that must be exceeded before the fluid starts to flow. After a Bingham plastic begins to flow, the rate of shear versus the shear stress curve is linear. See Newtonian fluid.

involving chemical reactions in living organisms.

a process similar to composting.

renewable energy available from materials derived from living or once living sources. It is sometimes called biofuel, which is fuel that is derived from biological sources, such as algae, wood, manure, and straw. Bioenergy includes biomass, which is the biological material used as biofuel. Bioenergy is the energy extracted from biomass. Biomass is fuel and bioenergy is the energy in the fuel.

a part of a stratigraphic unit that differs in its fossil fauna and flora from the rest of the unit.

produced by living organisms.

a reef or mound built by small organisms and their remains, such as coral, plankton, and oysters. Originally a wave-resistant coral structure served as an anchor for calcareous debris that formed limestone. It was tectonically submerged, or the sea level rose faster than the corals could build it, and it was eventually buried beneath marine shales. A bioherm is often porous enough to hold large accumulations of hydrocarbons, especially if it has been dolomitized. A bioherm is a stratigraphic trap.

an energy-producing reaction in living bacteria cells involving the transfer of hydrogen atoms or electrons from one molecule to another.

the total mass of living organisms per unit volume per unit of time.

a polymer produced by the action of a particular strain of bacteria on carbohydrates, used for increasing apparent viscosity and yield point with moderately good filtration control. Also called X-C polymer.

a drilling mud formulated with a biopolymer.

1. the process of breaking down organic wastes with microbes. Bacteria that are naturally present in the environment use microbial enzymes to break down the materials into a soluble form that passes through the cell walls of the bacteria. The bacteria metabolize the material and convert it into components that are more readily assimilated in the environment, such as water or carbon dioxide (i.e., a gardener’s compost pile). 2. the creation of engineered and managed conditions to boost natural biore­med­­iation processes. Nutrients are added to stimulate the bacteria naturally present in the waste. Oxygen and pH levels are adjusted for maximum effectiveness, and, if conditions are right, the bacteria grow in large numbers and break down the hydrocarbons much more rapidly than with natural bioremediation. In cases in which the necessary bacteria are not already present in the waste, suppliers can provide them along with the appropriate nutrients.

the thin zone of air, water, and soil where all terrestrial life exists.

using the fossils contained in rock strata to determine the relative ages of the rock strata. Sediments of the same age can look completely different because of variations in the sedimentary environment-for instance; one section may be made up of clays while another may be made up of limestone. However, if the fossils in the sediments are similar, the two sediments are likely to have been laid down at the same time.

the animals, plants, fungi, etc., of a region or period.

relating to life, biologic; relating to the actions of living organisms.

a type of mica that is high in magnesium and dark in color.

of a material capable of assuming a positive or negative electric charge, such as a bipolar transistor.

to supervise another too closely or continuously.

a wire rope that has been flattened and the strands of which have been spread. v: to flatten and spread the strands of a wire rope.

see wickered.

wire rope used for hoisting that has had its wires distorted into the shape of a birdcage by a sudden release of load.

(pronounced bi-stable) capable of assuming either of two stable states.

see flip-flop circuit.

the cutting or boring element used in drilling oil and gas wells. The bit consists of a cutting element and a circulating element. The cutting element is steel teeth, tungsten carbide buttons, industrial diamonds, or polycrystalline diamonds (PDCs). These teeth, buttons, or diamonds penetrate and gouge or scrape the formation to remove it. The circulating element permits the passage of drilling fluid and utilizes the hydraulic force of the fluid stream to improve drilling rates. In rotary drilling, several drill collars are joined to the bottom end of the drill pipe column, and the bit is attached to the end of the drill collars. Drill collars provide weight on the bit to keep it in firm contact with the bottom of the hole. Most bits used in rotary drilling are roller cone bits, but diamond bits are also used extensively.

an occurrence in which a mass of sticky consolidated material, usually drill cuttings, collect on the bit. A balled-up bit usually cannot drill efficiently.

a special device that fits into a bit breaker adapter (a plate that goes into the rotary table) and conforms to the shape of the bit. Rig workers place the bit to be made up or broken out of the drill stem into the bit breaker and lock the rotary table to hold the bit breaker and bit stationary so that they can tighten or loosen the bit.

a heavy plate that fits into the rotary table and holds the bit breaker; a device used to hold the bit while it is being made up or broken out of the drill stem.

on a roller cone bit, a cone-shaped steel device from which the manufacturer either mills or forges steel teeth, or into which the manufacturer inserts tungsten carbide buttons. Most roller cone bits have three cones, which roll, or rotate, on bearings as the bit rotates. As the cones roll over the formation, the cutters on the cone scrape or gouge the formation to remove the rock.

the cutting elements of a bit.

1. a member of a cable-tool drilling crew who repairs bits. 2. a machine used to repair, sharpen, and gauge bits.

the tendency of the bit to move other than vertically, caused by an inter-action between the rotation of the bit and the varying resistance of the formation being drilled.

a measure of the work a drill bit performs when it is on bottom and drilling.

see drill pipe float.

a phenomenon that occurs when the drilling rate becomes so high that drilling fluid-even if it is air, gas, or foam-cannot remove the cuttings from under the bit; consequently, the cuttings prevent the bit from drilling and it flounders.

a circular ring used to determine whether a bit is of the correct outside diameter. Bit gauges are often used to determine whether the bit has been worn down to a diameter smaller than specifications allow; such a bit is described as undergauge.

the measure of hydraulic power expended through the bit nozzles for cleaning the bit cutters and the hole bottom.

on a diamond bit, the material (usually powdered and fused tungsten carbide) into which the diamonds are set.

see nozzle.

the threaded element at the top of a bit that allows it to be made up in a drill collar or other component of the drill stem.

on diamond bits, the pattern in which the diamonds are placed in the face of the bit.

in fixed-head bits, the shape of the cross section of the body of the bit.

a plan for the expected number and types of bits that are to be used in the drilling of a well. The bit program takes into account all the factors that affect bit performance so that reliable cost calculations can be made.

a report that lists each bit used during a drilling operation, giving the type, the footage it drilled, the formation it penetrated, its condition, and so on.

the placing of a bit on the bottom of the hole, drilling with it until it drills the prescribed amount of hole, or until it wears out, and pulling it out of the hole.

the threaded portion of the top of the bit that is screwed into the drill collar. Also called the pin.

a sub inserted between the drill collar and the bit. See sub.

the tendency of the bit to drill in the direction of rotation in an inclined hole; e.g., a right-rotating bit walks to the right.

the motion a bit makes when it does not rotate around its center but instead drills with a spiral motion. It usually occurs to a bit drilling in a soft or medium soft formation when the driller does not apply enough weight or does not rotate the bit fast enough. A whirling bit drills an overgauge hole (a hole larger than the diameter of the bit) and causes the bit to wear abnormally.

a compound of asphalt and filler that is used to coat metals exposed to corrosion or weathering.

a substance of dark to black color consisting almost entirely of carbon and hydrogen with very little oxygen, nitrogen, or sulfur. Bitumens occur naturally and can also be obtained by chemical decomposition.

see oil shale.

black; used in drilling reports.

see diorite.

the total loss of power on a drilling rig or production facility. v: to totally lose power on a drilling rig or production facility.

casing without perforations.

a solid disk used to dead-end, or close off, a companion flange.

a heavy wall sub placed in the tubing string opposite flowing perforations.

liner with no perforations.

to close off (as with a blank flange or bull plug).

pipe, usually casing, with no perforations.

a gas phase above a liquid phase in a vessel. It is placed there to protect the liquid from contamination, to reduce the hazard of detonation, or to pressure the liquid. The gas has a source outside of the vessel.

a thin layer of sand or sandstone covering a large area. Also known as sheet sand.

a plug used to cut off flow of liquid.

in an oscilloscope, a positive or negative square-wave variation in electrical power (a pulse) that switches off a part of the oscilloscope’s screen for a predetermined length of time.

a tubing sub made of abrasion-resistant material. It is used in a tubing string where high-velocity flow through perforations may cause external erosion.

the drilling of holes into the earth for the purpose of placing a blasting charge (such as dynamite) in them.

see shooting rock.

coverings used to contain flying debris and rock caused by the use of explosives during pipeline ditching.

bailed; used in drilling reports.

to drain off liquid or gas, generally slowly, through a valve called a bleeder. To bleed down, or bleed off, means to release pressure slowly from a well or from pressurized equipment.

a pipe through which pressure is bled, as from a pressurized tank, vessel, or other pipe.

a special valve used to bleed pressure slowly from a line or vessel. Also called a blow-down valve.

a representative sample taken from any suitable point in a tank, or from a tank side sample connection after mixing the tank contents and before any significant separation of phases has occurred.

a device used to blend slurries or gels, usually mobile equipment.

a petroleum product that is mixed, or blended, with another petroleum product.

a circular metal disk installed in a pipeline to prevent flow by fastening it between flanges. v: to close a line to prevent flow.

a drilling operation in which the drilling fluid is not returned to the surface; rather, it flows into an underground formation. Sometimes blind-drilling techniques are resorted to when lost circulation occurs.

the end of a device, such as the end of a cylinder used in a riser tensioning system, which is capped and completely closed, or blinded.

see target.

an integral part of a blowout preventer, which serves as the closing element on an open hole. Its ends do not fit around the drill pipe but seal against each other and shut off the space below completely. See ram.

a blowout preventer in which blind rams are the closing elements. See blind ram.

see shear ram.

on the pontoons of some of the earliest semisubmersible rigs, a relatively small protuberance on the pontoon’s side that widened the pontoon and increased the rig’s stability.

isolated convex deformation of a paint that occurs when one or more of the coats become detached. The deformations resemble blisters that occur under human skin.

a housing built around controls on equipment that is sensitive to cold, such as heater-treaters.

Bureau of Land Management.

any assembly of pulleys on a common framework; in mechanics, one or more pulleys, or sheaves, mounted to rotate on a common axis. The crown block is an assembly of sheaves mounted on beams at the top of the derrick or mast. The drilling line is reeved over the sheaves of the crown block alternately with the sheaves of the traveling block, which is hoisted and lowered in the derrick or mast by the drilling line. When elevators are attached to a hook on a conventional traveling block, and when drill pipe is latched in the elevators, the pipe can be raised or lowered in the derrick or mast. See crown block, traveling block.

a high-integrity valve with double seals and with provision for determining whether either seal leaks.

a hoisting device made up of a pulley or pulleys (sheave or sheaves), which are mounted in a metal holder (a block), and wire rope (tackle) that is threaded (reeved) through the sheaves of the blocks. See block.

FERC proposal calling for separation of old and new gas into blocks, or batches, for interstate sales and shipping.

a three-dimensional perspective view of a cube, or block, of earth. It is developed from cross sections of the area.

a technique in squeeze cementing in which (1) the zone below the producing interval is perforated and a high-pressure squeeze carried out; (2) the zone above the producing interval is perforated and squeezed off in a similar manner; (3) the hole is drilled out; and (4) the producing interval is perforated. The purpose of block squeezing is to isolate the producing interval and prevent communication with the sand immediately above and below the producing interval.

a valve that completely shuts off flow of a fluid. It is usually either completely open or completely closed.

a diode that restricts (blocks) the flow of current in an undesirable direction in a circuit. See diode.

heavy lifting mechanism used on rigs to provide a mechanical pulling and running advantage.

the discharge pipe from a well being drilled by air drilling. The blooey line is used to conduct the air or gas used for circulation away from the rig to reduce the fire hazard as well as to transport the cuttings a suitable distance from the well. See air drilling.

the color of fluorescent light exhibited by some oils when viewed by reflected light. This usually differs from the color as seen by transmitted light.

a thin film on the top of a coat of paint that reduces the luster or veils its depth of color.

1. to supercharge an engine. See supercharge. 2. to depressure. See depres-sure.

1. a pressurized device capable of transferring liquid; sometimes used to transfer crude oil and water mixtures if pump agitation would create unwanted emulsions. 2. a small tank in which liquids are accumulated and drained by applying gas or air pressure above the liquid level. Such a vessel is usually located below a pipeline or other equipment at a location where an outside power source is not convenient for removing the drained liquids. Sometimes referred to as a drip.

to empty or depressure a vessel. Also called depressure.

1. to suddenly expel oilwell fluids from the borehole with great velocity. 2. to expel a portion of water and steam from a boiler to limit its concentration of minerals.

see bleeder valve.

the percentage of gases that escape past the piston rings from the combustion chamber into the crankcase of an engine.

1. the emptying or depressurizing of material in a vessel. 2. the material thus discarded.

that period following the completion of a cycling or pressure maintenance operation in a reservoir in which the remaining gas is produced from the reservoir without being replaced by injected gas.

supercharged. See supercharge.

fatty oil the viscosity of which has been increased by blowing air through it at an elevated temperature.

a device that permits or arrests a flow of liquid from a receptacle or through a pipe, faucet, tap, or stop valve.

an uncontrolled flow of gas, oil, or other well fluids into the atmosphere or into an underground formation. A blowout may occur when formation pressure exceeds the pressure applied to it by the column of drilling fluid and rig crew members fail to take steps to contain the pressure. Before a well blows out, it kicks; thus a kick precedes a blowout. See kick.

one of several valves installed at the wellhead to stop (prevent) the escape of pressure either in the annular space between the casing and the drill pipe or in open hole (i.e., hole with no drill pipe) during drilling or completion operations. Blowout preventers on land rigs are normally located beneath the rig at, or slightly below, the land’s surface; on jackup or platform rigs, at the water’s surface; and on floating offshore rigs, on the seafloor. See annular blowout preventer, ram blowout preventer, wireline preventer.

a device that stores hydraulic fluid under pressure in special containers and provides a method to open and close (operate) the blowout preventers quickly and reliably. Usually, compressed air and hydraulic pressure provide the opening and closing force in the unit. See blowout preventer. Also called an accumulator.

in drilling from offshore floating rigs, a metal fitting connected to the top of the annular preventer in the subsea blowout preventer stack. The mandrel has a mating-and-seal profile to match that of the lower marine riser package’s (LMRP’s) connector. The connector normally has the same pressure rating as the LMRP’s annular preventer.

in drilling from floating drilling rigs using a subsea blowout preventer, a special device that controls (regulates) the pressure to the inlet ports of a subsea blowout preventer’s subsea pilot manipulated (SPM) valves, which, in turn, operate the ram preventers, wellhead and lower marine riser package (LMRP) connectors, and subsea choke and kill valves.

a device that engages the helix of a tubing hanger’s running and orientation tool to orient a dual-bore tubing hanger within the wellhead. The pin is a spring retracted hydraulic piston that has the same pressure rating of the blowout preventer because it could be exposed to well­bore fluids.

an assembly of blowout preventers placed on top of each other (stacked one on top of the other), which typically consists of one or two annular preventers and three, four, or more ram preventers. See annular blowout preventer, blowout preventer, ram preventer.

controls, usually located near the driller’s position on the rig floor, that are manipulated to open and close the blowout preventers. See blowout preventer.

a training procedure to determine that rig crews are familiar with correct operating practices to be followed in the use of blowout prevention equipment.

see blowout preventer control unit.

the closing and sealing components of a preventer. Corresponds to the gate in the gate valve.

jamming or wedging of the drill string in the borehole by sand or shale that is driven uphole by formation fluids during a blowout.

barrels of liquid per day; usually used in reference to total production of oil and water from a well.

see hydraulic control pod.

in clear paints, a milky opalescence caused by the deposition of moisture from the atmosphere or the precipitation of one or more of the solid constituents of the paint.

barrels of oil; used in drilling reports.

see gauger’s bob.

an extraction plant without fragmentation facilities.

used to indicate the consistency of a paint.

an internal mechanism employed in certain tools to lock cones to the mandrel.

transverse or longitudinal seismic waves transmitted in the interior of an elastic solid or fluid and not related to a boundary surface.

in mineralogy, the arrangement of the layers of spheres making up the mineral in which the second sphere layer lies over the holes (interstices) between the spheres of the base layer. Each successive layer lies over the interstices of the layer below.

see weathering test.

a closed pressure vessel that has a furnace equipped to burn coal, oil, or gas and that is used to generate steam from water.

water piped into a boiler from which steam is generated.

fuel suitable for generating steam or hot water in large industrial or electricity-generating utility applications.

natural gas used as a fuel for the generation of steam or hot water.

(slang) to make up a report on a condition as fact without knowledge of its accuracy. Sometimes referred to as “doghouse.”

the temperature at which the vapor pressure of a liquid becomes equal to the pressure exerted on the liquid by the surrounding atmosphere. The boiling point of water is 212°F or 100°C at atmospheric pressure (14.7 pounds per square inch gauge or 101.325 kilopascals). Same as boiling temperature.

(slang) an inexperienced rig or oilfield worker; sometimes shortened to weevil.

(slang, obsolete) the work station of an inexperienced rotary helper, on the opposite side of the rotary from the rotary helper who sets pipe back on the rig floor during trips.

a tubing hanger.

a metal fastener made from a threaded pin or rod, usually with a square or hexagonal head at one end, which is inserted through holes in assembled parts and secured by a mated nut that is tightened by applying torque.

process of simultaneously tightening all of the bolts to allow the flanges to tighten evenly.

in drilling from floating drilling rigs using a subsea blowout preventer and riser system, a riser connector in which bolts are screwed into threaded holes in a flange welded on the end of the riser. The bolts are tightened to strict specifications with special torque wrenches to avoid failure of the connection. See riser pipe.

a thick-walled container, usually steel, used to hold devices that determine and record pressure or temperature in a wellbore. See bottomhole pressure.

a device set in a tubing coupling to facilitate the landing of pressure bombs (recorders).

the adhering or joining together of two materials (as cement to formation). v: to adhere or to join to another material.

1. the part of a valve that packs off and encloses the valve stem. 2. on a ram blowout preventer, the housing that surrounds the rams and contains the operating piston and rod.

a cash payment by the lessee for the execution of an oil and gas lease by the mineral owner; expressed as dollars per acre. Occasionally, an oil payment or overriding royalty may be reserved as a bonus by a lessor in addition to regular royalty.

a system of symbolic logic based on algebraic symbols representing such logical operations as AND, OR, and NOR.

1. a movable arm of tubular or bar steel used on some types of cranes or derricks to support the hoisting lines that carry the load. 2. floating device used to contain oil. 3. a period of high activity in the oil industry. 4. a member hinged to the revolving superstructure and used as part of an attachment.

the angle above horizontal of the longitudinal centerline of the boom base section.

a main corner member of a lattice-type boom.

a ratchet device on a crane that prevents the boom of the crane from being lowered but still permits it to be raised. Also called a boom ratchet.

rope drum(s) and its drive, or other mechanism for controlling the angle of the boom.

structural truss members at angles to and supporting the boom chords of a lattice-type boom.

the straight line distance from the centerline of a boom foot pin to the centerline of a boom point load hoist sheave pin.

the large-diameter wire rope or the strands that support the boom of a crane.

see boom dog.

crane booms are usually in two sections, upper and lower; such booms may be lengthened by insertion of one or more additional sections.

splicing connections for sections of a basic crane boom and additional sections usually of the splice plate type, pin type, or butt type.

the steel projections on a crane struck by the boom if it is raised too high or lowered too far.

1. (slang) an oilfield worker who moves from one center of activity to another; a floater or transient. 2. a device used to tighten chains on a load of pipe or other equipment on a truck to make it secure.

on a diesel engine, a small manually or electrically operated pump that an engine operator can use to prime the engine’s fuel system for starting the engine. When activated, the pump moves fuel from a tank, through the engine’s fuel lines, and to the engine’s injectors, ensuring that fuel is available for starting the engine.

an installation on a pipeline that maintains or increases pressure of the fluid coming through the pipeline and being sent on to the next station or terminal.

usually a small pump mounted upstream of another pump that charges the fluid being pumped prior to the fluid’s reaching the main pump.

1. a tubular device placed in a vertical position, either inside or outside a larger vessel, and through which well fluids are conducted before they enter the larger vessel. A boot aids in the separation of gas from wet oil. Also called a flume or conductor pipe. 2. a large pipe connected to a process tank to provide a static head that can absorb surges of fluid from the process tank. Also called surge column.

see boot sub.

a device made up in the drill stem above the mill to collect bits of junk ground away during a milling operation. During milling, drilling mud under high pressure forces bits of junk up the narrow space between the boot sub and hole wall. When the junk reaches the wider annulus above the boot sub and pressure drops slightly, the junk falls into the boot sub. A boot sub also can be run above the bit during routine drilling to collect small pieces of junk that may damage the bit or interfere with its operation. Also called a junk sub or junk boot.

blowout preventer.

see blowout preventer stack.

see blowout preventer control unit.

its purpose is to engage with the tubing hanger running and orientation tool helix and orientate the dual-bore tubing hanger within the wellhead. The pin is simply a spring retract hydraulic piston and must be rated to the operating pressure of the BOP since it could be exposed to wellbore fluids.

the assembly of blowout preventers installed on a well. See blowout preventer stack.

barrels of oil per day.

blowout preventer equipment.

1. the inside diameter of a pipe or a drilled hole. 2. the diameter of the cylinder of an engine. v: to penetrate or pierce with a rotary tool. Compare tunnel.

a device suspended inside a wellhead that protects the casing hanger’s sealing surfaces inside the wellhead housing before the casing hangers are installed.

a hole under a road, railroad, stream, or other obstacle under which a pipeline must cross. It is created by using an auger or other type of drill.

the wellbore; the hole made by drilling or boring. See wellbore.

an effect that occurs when certain shale zones are penetrated by the wellbore and the pressure exerted by the drilling mud exceeds the pressure exerted by the shale. The pressure differential causes the borehole to flex, or balloon, and the borehole no longer behaves as a fixed, rigid cylinder.

false influence on well logging measurement caused by the borehole environment, e.g., diameter, shape, rugosity, type of fluid, or mud cake.

the total pressure exerted in the wellbore by a column of fluid and any back-pressure imposed at the surface.

any logging device whose operation depends on a portion of the logging tool touching the wellbore.

obtained by collecting the chips made by boring holes with a ship auger from the top to the bottom of the material contained in a barrel, case, bag, or cake.

in the mathematical operation of subtraction, the act of taking the number 1 from the tens, hundreds, or other column to the left of the ones column, and placing it to the left of the number in the ones column, to raise the number in the ones column to the next higher order digit. This action reduces the number that was borrowed from by 1. Borrowing then continues, if necessary, in each subsequent column to the left until the solution is achieved. For example, to subtract 679 from 831, 1 is borrowed from 3 in the tens column of 831, which leaves 2. Nine is then subtracted from 11 to leave 2. Next, 7 is subtracted from 12, because 1 was borrowed from the hundreds column to make 12. This action leaves 5. Finally, 6 is subtracted from 7 in the hundreds column, which was reduced by 1 when it was borrowed from earlier. This action leaves 1. So, the answer is 152.

a method of collecting a relatively small portion of liquid (a sample) from a large tank or vessel in a glass container (a bottle) using methods that ensure that the small sample is a reasonable representation of the liquid in the tank or vessel.

a test in which different chemicals are added to bottle samples of an emulsion to determine which chemical is the most effective at breaking the emulsion into oil and water. Once an effective chemical is determined, varying amounts of it are added to bottle samples of the emulsion to determine the minimum amount required to break the emulsion effectively.

see semi­submersible drilling rig.

a mobile submersible drilling structure constructed of several steel cylinders or bottles. When the bottles are flooded, the rig submerges and rests on bottom; when water is removed from the bottles, the rig floats. The latest designs of this type of rig drill in water depths up to 100 feet (30.5 metres). See submersible drilling rig.

see bottle-type submersible rig.

liquefied petroleum gas placed in small containers for sale to domestic customers.

an area of reduced diameter in pipe caused by excessive longitudinal strain or by a combination of longitudinal strain and the swaging action of a body. A bottleneck may result if the downward motion of the drill pipe is stopped with the slips instead of the brake.

an elevator that is bored to match the 18-degree taper of a tool joint.

large-diameter steel cylinders used to support submersible and semi-submersible rigs.

the angle formed where the bottom and the side of the oil tank meet, usually nearly 90°.

boots worn to protect from punctures and foot and ankle injuries. Usually rubber boots with a steel shank in the sole and a steel toe.

the positioning of the piston at the lowest point possible in the cylinder of an engine; often marked on the engine flywheel.

a bar welded to the bottom of a tank to which guide wires or cables for the float of an automatic tank gauge are attached.

a mechanism for anchoring a bottomhole pump in a well; located on the lower end of the pump. Compare top hold-down.

the pressure exerted on the bottom hull of a column-stabilized semisubmersible drilling rig when the hull is submerged to drilling water depth.

to reach the lowest level.

a cement wiper plug that precedes cement slurry down the casing. The plug wipes drilling mud off the walls of the casing and prevents it from contaminating the cement. See cementing, wiper plug.

in tank sampling, a sample obtained from the material near the bottom surface of the tank, container, or line at a low point.

a device run at or near the bottom of the tubing string to which production tools can be attached.

the total amount of time, measured in minutes, from the time a diver leaves the surface until he or she begins the ascent. Also called working time.

water found below oil and gas in a producing formation.

a device placed in the cementing head and run down the casing in front of cement to clean the mud off the walls of the casing and to prevent contamination between the mud and the cement.

a submersible pump configuration in which the pump and the motor sections are reversed, with the pump intake through a stinger at the bottom of the unit. It is used where casing size prohibits the desired production volume because of tubing friction loss or pump diameter restriction.

an offshore pipeline construction technique in which the pipe string remains below the surface while it is towed to its final location.

a type of mobile offshore drilling unit (MODU) that has a part of its structure in contact with the seafloor when it is on site and drilling a well. The remainder of the rig is supported above the water. The rig can float, however, allowing it to be moved from one drill site to another. Bottom-supported units include submersible rigs and jackup rigs. See mobile offshore drilling unit.

see water drive.

a spot sample of free water taken from beneath the petroleum contained in a ship or barge compartment or a storage tank.

the lowest or deepest part of a well. adj: pertaining to the bottom of the wellbore.

the portion of the drilling assembly below the drill pipe. It can be very simple-composed of only the bit and drill collars-or it can be very complex and made up of several drilling tools.

a device with a restricted opening placed in the lower end of the tubing to control the rate of flow. See choke.

a contract providing for the payment of money or other considerations upon the completion of a well to a specified depth.

see bottomhole choke.

an electric heater screwed onto lengths of tubing and lowered into the well. It raises the bottomhole temperature of the well to prevent solidification of paraffin in subsurface equipment.

a contract providing for the payment of money or other considerations on the completion of a well to a specified depth, regardless of whether the well is a producer of oil or gas or is a dry hole.

money paid by a contributing company in exchange for the information received from the drilling on the completion of a well to a specified depth, regardless of whether the well is a producer of oil or gas or is a dry hole.

a device, installed near the bottom of the hole, that blocks passage through the annular space between two strings of pipe. See packer.

a bridge plug or cement plug placed near the bottom of the hole to shut off a depleted, water-producing, or unproductive zone.

1. the pressure at the bottom of a borehole. It is caused by the hydrostatic pressure of the wellbore fluid and, sometimes, by any back-pressure held at the surface, as when the well is shut in with blowout preventers. When mud is being circulated, bottomhole pressure is the hydrostatic pressure plus the remaining circulating pressure required to move the mud up the annulus. 2. the pressure in a well at a point opposite the producing formation, as recorded by a pressure-tight container mechanism referred to as a bottomhole pressure bomb.

a pressure-tight container (bomb) used to record the pressure in a well at a point opposite the producing formation.

an instrument to measure bottomhole pressure. Also called bottomhole pressure bomb.

a test that measures the reservoir pressure of the well, obtained at a specific depth or at the midpoint of the producing zone. A flowing bottomhole pressure test measures pressure while the well continues to flow; a shut-in bottomhole pressure test measures pressure after the well has been shut in for a specified period of time. See bottomhole pressure, bottomhole pressure gauge.

any of the rod pumps, high-pressure liquid pumps, or centrifugal pumps located at or near the bottom of the well and used to lift the well fluids. See centrifugal pump, hydraulic pumping, submersible pump, sucker rod pumping.

a device used to separate oil and gas at the bottom of wells to increase the volumetric efficiency of the pumping equipment.

temperature measured in a well at a depth at the midpoint of the thickness of the producing zone.

a test that measures the temperature in a well at a depth at the midpoint of the thickness of the producing zone.

1. the liquids and the residue that collect in the bottom of a vessel (such as tank bottoms) or that remain in the bottom of a storage tank after a period of service. 2. the residual fractions remaining at the bottom of a fractionating tower after lighter components have been distilled off as vapors.

a complete trip from the bottom of the wellbore to the top.

the time required for mud to travel up the borehole from the bit to the surface.

the part of a marine delta that lies farthest from shore. It consists of silt and clay extending well out from the toe of the steep delta face. Such beds grow slowly, out of reach of most of the effects of river current and wave action.

a rapid dive with a very short bottom time to minimize decompression time.

a pressure-sensing element consisting of a twisted or curved tube of noncircular cross section, which tends to straighten when pressure is applied internally. By the movements of an indicator over a circular scale, a Bourdon tube indicates the pressure applied.

in geophysics, a map of the gravitational field over an area that includes a correction for Bouguer gravity anomaly. Bourguer gravity anomaly is a value that corrects the observed gravity for latitude and elevation variations, plus the mass of material above some datum (usually sea level).

the nautical term for the forward part of a ship or vessel.

the lines running from the bow of a mobile offshore drilling rig, especially the forward mooring lines.

a control barge used between the towboat and the barge to give more control in steering the barge down the waterway.

in drilling operations, an insert that fits into the opening of a master bushing and accommodates the slips.

a knot used primarily in lifting heavy equipment with the catline, since it can be readily tied and untied regardless of the weight of the load on it.

the female section of a connection. See tool joint.

see tool joint.

old-style tap with longitudinal grooves across the threads. See tap, taper tap.

threads on the female section, or box, of a tool joint. See tool joint.

the principle that states that at a fixed temperature, the volume of an ideal gas or gases varies inversely with its absolute pressure. As gas pressure increases, gas volume decreases proportionately.

barrels per day.

barrels per hour; used in drilling reports.

before payout; commonly used in land departments.

water that contains relatively low concentrations of soluble salts. Brackish water is saltier than fresh water but not as salty as salt water.

a condition in which the weight on a bit tooth has been so great that the tooth has dulled until its softer inner portion caves over the harder case area.

(obsolete) casinghead. Glen T. Braden invented a casinghead in the 1920s that became so popular that all casingheads were called bradenheads.