Glossary

watt.

wireline.

water cushion; used in drilling reports.

weighted average cost of gas.

water-alternating gas.

in pipeline construction, a multiheaded circular propane torch that is manually rotated inside the end of a pipe for preheating.

a well-killing method in which the well is shut in and the mud weight is raised the amount required to kill the well. The heavy mud is then circulated into the well while the kick fluids are circulated out. So called because one shuts the well in and waits for the mud to be weighted before circulation begins.

pertaining to the time when drilling or completion operations are suspended so that the cement in a well can harden sufficiently.

pertaining to the time when drilling or other operations are suspended because of bad weather.

the horizontal steel member of a beam pumping unit that has rocking or reciprocating motion. See beam pumping unit.

also called filter cake or mud cake. See filter cake.

a device used in fishing for drill pipe. If the upper end of the lost pipe is leaning against the side of the wellbore, the wall hook centers it in the hole so that it may be recovered with an overshot, which is run on the fishing string and attached to the wall hook.

see differential sticking.

in tubular goods such as drill pipe, tubing, or casing, the width, or breadth, of the metal making up the sides (the wall) of the tubular. Wall thickness determines the inside diameter of the tubular and therefore affects the maximum size of a tool that can be run through the it.

the ability of a drilling mud to plaster the wall of the hole with solids from the drilling mud.

see wall hook.

see hook-wall packer.

a condition in which the drill stem becomes stuck against the wall of the wellbore because part of the drill stem (usually the drill collars) has become embedded in the filter cake. Necessary conditions for wall sticking are a permeable formation and a pressure differential across a nearly impermeable filter cake and drill stem. Also called differential sticking.

see differential sticking.

the tendency of the drill bit to deviate horizontally parallel to tilted strata.

a government-financed, nonpro­fit corporation of eleven oil and pipeline companies established during World War II to build desperately needed pipelines such as Big Inch and Little Big Inch.

see heat a connection.

a front that is formed when warm air replaces cold air as the cold air retreats.

a weather phenomenon that occurs when a cold front overtakes a warm or stationary front and is characterized by the coldest air being ahead of the warm front. The cold front is forced aloft. Compare cold occlusion, neutral occlusion.

rock strata that are slightly tilted occur when broad areas of the crust rise or drop without fracturing.

the clause in an oil and gas lease that assures title to the leased property by an express covenant to that effect.

a deed in which the grantor stipulates by express covenant that the title to property is as it is represented to be and that the grantee’s possession shall be undisturbed. Defects in title may include those that may have existed before the grantor obtained the title as well as any that have arisen during his or her ownership.

a wire-rope strand design that consists of a single, central wire surrounded by two outer layers of several wires. The wires in the inner layer are the same diameter as the inner wire. The wires in the outer layer are of two diameters, one smaller wire laying adjacent to one larger wire. A typical Warrington strand has 19 wires: 1 central wire, 6 inner wires, and 12 outer wires, 6 of which are smaller in diameter than the other 6.

a thin fluid that separates drilling mud from cement when cement is pumped downhole. A wash also removes mud from the walls of the hole by both turbulent and surfactant action.

see absorption oil.

to release pipe that is stuck in the hole by running washover pipe. The washover pipe must have an outside diameter small enough to fit into the borehole but an inside diameter large enough to fit over the outside diameter of the stuck pipe. A rotary shoe, which cuts away the formation, mud, or whatever is sticking the pipe, is made up on the bottom joint of the washover pipe, and the assembly is lowered into the hole. Rotation of the assembly frees the stuck pipe. Several washovers may have to be made if the stuck portion is very long.

a tank containing heated water through which crude-oil emulsion is forced to flow to remove water from the crude. Also called a gun barrel.

1. the high-pressure spraying of the crude oil cargo to dislodge or dissolve clingage and sediment from the walls, cross members, and lines in the compartments of a vessel during the unloading operation. 2. the use of a high-pressure water stream to dislodge clingage and sediment from the bulkheads, bottoms, and internal structures of a vessel’s cargo tanks.

displacing mud in the tubing by pumping salt water into it to start the flow of formation fluids.

1. excessive wellbore enlargement caused by solvent and erosional action of the drilling fluid. 2. a fluid-cut opening caused by fluid leakage.

the operation during which stuck drill stem or tubing is freed using washover pipe.

see washover pipe.

a fishing tool that is made up in a length of washover pipe connected to the top of the fish once the washover is completed, and then backed off the fish, thus enabling the washed-over part of the fish to be retrieved. The tool permits washover, back-off, and pulling to be carried out in one round trip.

an accessory used in fishing operations to go over the outside of tubing or drill pipe stuck in the hole because of cuttings, mud, and so forth, that have collected in the annulus. The wash­over pipe cleans the annular space and permits recovery of the pipe. It is sometimes called washpipe.

see burn shoe.

the assembly of tools run into the hole during fishing to perform a washover. A typical washover string consists of a washover back-off connector, several joints of washover pipe, and a rotary shoe.

a short length of surface-hardened pipe that fits inside the swivel and serves as a conduit for drilling fluid through the swivel.

ayers of dense flexible material that is stacked around the swivel’s washpipe and the swivel’s interior body seal. It helps seal between the static washpipe and the turning swivel body to ensure that high-pressure drilling mud flows through the swivel’s stem and into the kelly.

the practice of reducing the amount of waste generated from a site through recycling programs and the use of nonhazardous chemical substitutes for hazardous chemicals.

circle of offset a rig will trace due to variables in environmental conditions.

in tank sampling, a sample obtained with a thief to determine the amount of material at the bottom of the tank that cannot be sold.

a reduction in the permeability of a formation caused by the invasion of water into the pores.

water accumulated at (or sometimes added to) the bottom of the oil in a storage tank.

the upward encroachment of water into a well caused by pressure drawdown from production.

additives used to prevent or minimize water loss into a formation during slurry placement.

water put into an empty string of pipe in a wellbore to prevent the pipe from being crushed by pressure in the annulus.

the percentage of water in fluid produced from a well. v: to locate the oil-water interface and use the location to measure the volumes of oil and water in a shore tank or ship compartment.

the prevention of liquid condensation in the pipeline grid under various pressures and temperatures. Water dew-point control methods include the silica gel, glycol, and molecular sieve.

the depth of free water in a container over and above the dip plate.

equipment used mostly on offshore or desert locations to convert salt water to potable fresh water.

the reservoir drive mechanism in which oil is produced by the expansion of the underlying water and rock, which forces the oil into the wellbore. In general, there are two types of water drive: bottom-water drive, in which the oil is totally underlain by water; and edgewater drive, in which only a portion of the oil is in contact with the water. Bottom-water drive is considered more efficient.

an oilfield in which the primary reservoir drive mechanism is water.

the movement of water into a producing formation as production depletes the formation of oil and gas.

a graduated rod, usually of metal, to which water-finding paper or paste can be applied. This paste or paper discolors on contact with water and thus affords a ready means of measuring the depth of water in a tank. Also called a water-finding rule.

a pressure concussion caused by suddenly stopping the flow of liquids in a closed container. See fluid knock.

pump used in waterflooding or in water disposal. In waterflooding, the pump injects water into a well drilled in one part of a reservoir to force oil to a production well. In water disposal, the pump injects water produced from a well into a reservoir for disposal.

a well into which water is pumped to dispose of the water or to recover oil in a waterflood.

in the cooling system, a passageway inside the rim for circulating water.

see water outlet.

see fluid loss.

see water distillation unit.

the part of a gun barrel that provides an outlet for the water that has separated from an emulsion and that regulates the amount of water held in the gun barrel.

in naval architecture, a flat and level surface (a plane) parallel to the surface of the water and defined by its line of intersection with the vessel’s hull.

dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt, and industrial, municipal, and agricultural waste discharged into water.

in a floating object, the force exerted by the water on the bottom and sides of the floating object.

on an engine, a device, powered by the engine, that moves coolant (water) through openings in the engine crankcase, through the radiator or heat exchanger, and back into the crankcase.

the percentage of total pore space in a reservoir occupied by water. It is normally estimated by electric log calculations, although cores specially obtained may be analyzed for this value.

a relatively small volume of water that is put into the drill string or tubing string on top of the drilling or workover fluid.

a string of casing used to shut off water above an oil sand.

1. the structure at the top of the drilling derrick or mast that supports the crown block. 2. the underground level at which water is found.

final test on a pipeline in which the line is filled with water and pressured up to a higher-than-normal operating pressure. If no leaks occur, the line is put into service.

water (H2O) in its gaseous state (vapor) that can be liquefied by compression or cooling.

a well drilled to obtain a fresh water supply to support drilling and production operations or to obtain a water supply to be used in connection with an enhanced recovery program.

the portion of an oil or gas reservoir occupied by water, usually the lowest zone in the reservoir.

an enhanced oil recovery method in which water is injected followed by gas, which is usually carbon dioxide (CO2). Injecting water followed by CO2 allows the water and gas to better sweep the reservoir; further, the water reduces the possibility of the gas channeling, which, if it occurs, leaves parts of the reservoir unswept by the gas. See enhanced recovery.

1. to reduce the weight or density of a drilling mud by adding water. 2. to reduce the solids content of a mud by adding water.

usually hydrochloric acid in water, a solution that is used to perform massive acid fractures in carbonate reservoirs. Acid concentrations of 22 percent to 28 percent provide maximum dissolving of carbonate rock. Small- to medium-sized sand can be added to the system to provide scouring of the fracture faces, along with corrosion inhibitors, demulsifiers, and clay stabilizing chemicals. Fresh water, in volumes of one to three times the acid volumes, is pumped between the various acid stages to dissolve sludge, which is a result of acid reacting with carbonate.

a solution used in water-base fracturing fluids that causes the fracturing fluid to solidify, or gel. Water-base gel is used primarily in sensitive sandstone reservoirs, which, if a gel were not used, would absorb excessive amounts of water and decrease the effectiveness of the fracturing fluid.

a drilling mud in which the continuous phase is water. In water-base muds, any additives are dispersed in the water. Compare oil-base mud.

the ratio of water to cement in a slurry. It is expressed as a percentage, indicating the number of pounds of water needed to mix 100 pounds (45.32 kilograms) of cement.

a measure of the amount of water in oil being produced by a well.

1. using the loca­tion of the oil-water interface to determine the volume of free water in a shore tank or vessel compartment. 2. the line of demarcation of the oil-water interface.

a material that changes color (usually to red) in water. The use of water-cut paste is one method by which the level of water in the bottom of an oil storage tank can be determined. The paste is applied to a plumb bob, which is lowered to the bottom of the tank and then retrieved. The water level is then measured off the bob by noting the depth of the red portion.

a strip of paper coated with a chemical substance that changes color on immersion in water. When fastened to a water finder, it indicates the depth of free water in a container.

a paste containing a chemical that changes color in contact with water. When applied to a water finder, it indicates the level of free water in a container.

see water finder.

see invert-emulsion mud.

a measure of the amount of produced water to the amount of produced oil in the total amount of fluids produced from a reservoir.

in naval architecture, the dimensions of the water plane created by a floating vessel; the area of a horizontal cross section of a floating vessel at the waterline for any given draft. See water plane.

the portion of an oil or gas reservoir from which water or mainly water is produced.

not allowing water to pass in, out, or through.

a door on ships or mobile offshore rigs that, when closed, blocks the passage of water and withstands its pressure.

on a ship or offshore rig, the vessel’s ability to prevent water from entering compartments on the vessel and thus maintain the vessel’s ability to remain afloat in spite of several compartments being flooded. To provide watertight integrity, naval architects design vessels so that they are divided into many sections or compartments, each of which can be sealed closed to prevent water from entering-that is, each compartment can be made watertight by closing watertight doors or hatches.

a hydrocarbon reservoir whose rock grains are coated with a film of water.

see wettability.

a hole inside a bit through which drilling fluid from the drill stem is directed.

of a well, producing mostly water (“gone to water”).

the first indication of increased oil production as the result of a waterflood project.

a method of improved recovery in which water is injected into a reservoir to remove additional quantities of oil that have been left behind after primary recovery. Waterflooding usually involves the injection of water through wells specially set up for water injection and the removal of water and oil from production wells drilled adjacent to the injection wells.

1. the line on the hull of a ship or floating rig to which the surface of the water rises when the ship or rig is floating. 2. any of several lines parallel to this line, marked on the hull of a ship or rig, which indicates the depth to which the ship or rig submerges under various loads.

see Plimsoll mark.

in general, the offshore equivalent of a tornado.

the unit of power in the metric system, equal to 1 joule per second, or 0.746 horsepower.

the application of 1 watt of power for 1 hour.

a quantity recorder that measures power and integrates, or adds up, the amount of power used over a period of time. Also called an integrating wattmeter.

see reactive power.

n instrument that measures the magnitude of the power in an electric circuit. It may read watts, kilowatts, or megawatts.

in electronics, a disturbance that begins at one point in a medium and goes to other points in the medium without permanently displacing the medium.

the top part of a wave.

a cyclone that develops and travels along a front. The circulation about the cyclone’s center may give the front a wavelike shape. Also called wave depression.

see wave cyclone.

the measurement of a wave from its trough to its crest.

a device that measures the heights of waves. Although many types are available, a commonly used one is firmly attached to the seabed or a stationary anchoring system at a depth of no more than about 65 feet or 20 metres. Devices in the instrument that transform pressure energy into height measurements (transducers) send signals to a recorder, which stores the information. Later, this information can be downloaded to a computer and analyzed.

the convergence of sea and swell or the convergence of two or more swells. See sea, swell.

the horizontal distance between two successive wave troughs or crests.

the time interval between the passage of two successive wave troughs or crests.

a diagram that depicts reported sea characteristics for a given area.

the ratio between a wave’s height and length.

the bottom part of a wave.

the speed at which an ocean wave moves; it is usually measured in metres or feet per second.

a bar having a wavy outline profile.

in electronics, the pictorial representation of the shape (form) of a wave, which is obtained by plotting the displacement of the wave as a function of time, at a fixed point in space. See wave.

see paraffin.

weber.

wildcat; used in drilling reports.

a fixed or removable cylindrical metal lining placed inside a fitting or piece of moving equipment that reduces friction and thus wear on the fitting.

in a roller chain drive, an amount of stretching that causes the chain to engage improperly with the sprockets.

a groove in a metal part that when worn smooth indicates that the part should be replaced.

a flat metal protrusion of a downhole tool that is usually hardfaced and that protects the rotating tool from wear.

1. a hollow cylindrical device installed around the swivel’s rotating stem that absorbs the stem’s rotation and helps form an oil seal between the stem and the oil-bath reservoirs inside the swivel. 2. in a riser adapter, a thin metal cylinder that fits inside the adapter and prevents premature wear on the inside bore of the adapter and drill stem components that rotate within it. See riser adapter.

the state of the atmosphere at a specific time with respect to heat or cold, wetness or dryness, calm or storm, and clearness or cloudiness. The term is also used to identify rain, storm, or other unfavorable atmospheric conditions. v: to allow an object or substance to age, usually under controlled conditions.

a chart that indicates atmospheric conditions and circulation over an area at a given time. Also called surface chart.

crude oil that has lost an appreciable quantity of its entrained gas because of evaporation during storage.

see radiofax.

1. the breakdown of large rock masses into smaller pieces by physical and chemical climatological processes. 2. the evaporation of liquid by exposing it to the conditions of atmospheric temperatures and pressure.

a Gas Processors Association test for LP gas for the determination of heavy components in a sample by evaporation of the sample as specified.

of a storage tanker or shuttle vessel that is permanently moored, to make a 360° circle around the mooring as the weather changes.

a vessel is allowed to change heading into the direction of the prevailing environment.

a brand name for one type of pipe tongs used on drilling rigs; sometimes used generically for all brands of tongs, even though other types of tongs exist.

the metric unit of magnetic flux.

1. a metal or wooden piece that tapers to a thin edge and is used for raising heavy objects or for tightening by being driven into or between something. 2. something wedge-shaped, as a portion of liquid in the hold of a tanker ship.

a formula for a trigonometric calculation to determine the oil remaining on board (ROB) when the vessel is out of trim and the ROB does not contact both forward and aft bulkheads. The formula assumes ROB to be a flowable liquid.

a mathematical means of approximating the small quantities of liquid and solid cargo and free water on board before a vessel is loaded and after its cargo is discharged, based on cargo compartment dimensions and vessel trim. It is used only when a wedge exists and when the liquid does not touch all bulkheads.

a device on Cameron ram blowout preventers that locks the rams on a subsea preventer closed so that even if hydraulic closing pressure is lost, the rams will remain closed and provide a seal. It is a wedge-shaped piston that is mounted in its own hydraulic housing on the back of each ram bonnet at 90 degrees to the operating piston’s tail shaft. Once the rams are closed, the Wedge Lock pistons are hydraulically operated and they move behind the operating piston tail shaft and wedge it into place.

wire rope fittings wherein the rope end is secured by a wedge.

precalculated ship’s tables based on the wedge formula and displayed in much the same way as the ship’s innage/ullage tables. Used for small quantities when the liquid does not touch all bulkheads.

a hole in the lantern ring of a liner packing in a mud pump. When the liner packing fails, fluid spurts out of the weephole with each stroke of the piston, indicating that the packing should be renewed. Also called tattletale hole, telltale hole.

shortened form of boll weevil. See boll weevil.

a device for determining either the mass or the weight of a body, depending on the apparatus and procedure employed.

a tank used with a weigh scale for measurement of the liquid contents of the tank.

1. in mud terminology, refers to the density of a drilling fluid. 2. of a measurement, expresses degree of confidence in result of measurement of a certain quantity compared with result of another measurement of the same quantity. 3. the force with which a body is attracted to the earth or to another celestial body equal to the product of the object’s mass and the acceleration of gravity.

see sinker bar. Also called stem.

a belt worn by a diver to achieve negative buoyancy.

the amount by which drilling fluid density is reduced by entrained formation fluids or air.

an instrument near the driller’s position on a drilling rig that shows both the weight of the drill stem that is hanging from the hook (hook load) and the weight that is placed on the bit by the drill collars (weight on bit).

to increase the weight or density of drilling fluid by adding weighting material.

in process control, a valve containing a weight that controls the valve’s opening and closing to control (regulate) the pressure in a vessel.

the amount of downward force placed on the bit by the weight of the drill collars.

a packer whose packing elements are activated when weight from the tubing string is applied. To set some packers, rotation as well as weight is required. See packer.

cost calculated as the total cost of all gas purchased during a base period divided by either the total quantity purchased (unit of production) or the system throughput (unit of sales) during the same period. This rate, plus any application of any pending surcharge adjustments, serves as the basis on which system tariff rates are computed and made effective.

a material that has a high specific gravity and is used to increase the density of drilling fluids or cement slurries.

a metal plate installed in a separator, treater, or mud tank and used to regulate liquid level or, in the case of a metering separator, to measure flow.

a pyroclastic deposit hardened by the action of heat, pressure from overlying material, and hot gases.

the hole made by the drilling bit, which can be open, cased, or both. Also called borehole, hole, or wellbore.

1. the activities and methods of preparing a well for the production of oil and gas or for other purposes, such as injection; the method by which one or more flow paths for hydrocarbons are established between the reservoir and the surface. 2. the system of tubulars, packers, and other tools installed beneath the wellhead in the production casing; that is, the tool assembly that provides the hydrocarbon flow path or paths. See completion.

the methods used to control a kick and prevent a well from blowing out. Such techniques include, but are not limited to, keeping the borehole completely filled with drilling mud of the proper weight or density during all operations, exercising reasonable care when tripping pipe out of the hole to prevent swabbing, and keeping careful track of the amount of mud put into the hole to replace the volume of pipe removed from the hole during a trip.

the ratio between the number of wells drilled in a field and the acreage. Under a 40-acre spacing pattern, the well density is one well per 40 acres.

the fluid, usually a combination of gas, oil, water, and suspended sediment, that comes out of a reservoir. Also called well stream.

see kick.

see log.

a private, or sometimes public, organization that maintains collections of oilfield data, particularly well logs. Users gain access to the information by paying membership dues or a user’s fee.

the recording of information about subsurface geologic formations, including records kept by the driller and records of mud and cutting analyses, core analysis, drill stem tests, and electric, acoustic, and radioactivity procedures. See acoustic log, core analysis, driller’s log, drill stem test, electric well log, mud analysis, and radioactivity log.

authorization, usually granted by a governmental conservation agency, to drill a well. A permit is sometimes also required for deepening or remedial work.

an offshore structure with a platform above the surface of the water that supports the producing well’s surface controls and flow piping.

in pipeline construction, a device installed in waterlogged soil to dry out areas along the ditch line. Functioning as a submersible pump, a well point is a hollow steel rod approximately 18 feet (5.5 metres) long driven into the ground. Its free end is connected by hose or tubing to a well-point pump that moves groundwater away from the ditch. Hundreds of well points may be required to stabilize an area.

a member of a well-servicing crew.

see toolpusher.

see well servicing.

a company that specializes in offshore well repair.

the maintenance work performed on an oil or gas well to improve or maintain the production from a formation already producing. It usually involves repairs to the pump, rods, gas-lift valves, tubing, packers, and so forth.

see location.

the regulation of the number and location of wells over an oil or gas reservoir as a conservation measure. Compare well density.

any of several operations used to increase the production of a well, such as acidizing or fracturing. See acidize, formation fracturing.

see well fluid.

see well logging.

a test performed on a well to determine its production characteristics.

the detailed results of a well test that present all test data, the calculations drawn from the data, and conclusions pertaining to the well’s production potential.

in well testing, an assembly of equipment that is attached to the wellhead of the well to be tested. The main component of a well test surface package is an oil and gas separator.

measures the time needed for a sound pulse generated at the surface to reach successive selected depths in the borehole. Used to correct problems in downhole acoustic logs caused by filtrate invasion of the formation and borehole irregularities. Also used to calibrate depths on seismic sections.

see workover.

an assembly of several components, such as ram preventers, annular preventers, a choke and kill system, trip tanks, and mud-gas separators. On offshore floating rigs, well-control equipment also includes a marine riser system and a diverter system.

a portable rig, truck-mounted, trailer-mounted, or a carrier rig, consisting of a hoist and engine with a self-erecting mast. See carrier rig. Compare workover rig.

interprets information transmitted from the downhole sonde to make corrections for downhole conditions, make complex calculations, and print out various log formats. Also keeps track of the depth at which the logs are being obtained and warns of malfunctions.

a borehole; the hole drilled by the bit. A wellbore may have casing in it or it may be open (uncased); or part of it may be cased, and part of it may be open. Also called a borehole or hole.

see wellbore soak.

1. bottomhole pressure. 2. casing pressure.

an acidizing treatment in which the acid is placed in the wellbore and allowed to react by merely soaking. It is a relatively slow process, because very little of the acid actually comes in contact with the formation. Also called wellbore cleanup. See matrix acidizing. Compare acid fracture.

the equipment installed at the top of the wellbore. A wellhead includes such equipment as the casinghead and tubing head. adj: pertaining to the wellhead (e.g., wellhead pressure).

on a floating drilling rig using a subsea blowout preventer stack, a tool that attaches the blowout preventer (BOP) stack to the wellhead. It is hydraulically operated from the surface and, when actuated, connects the BOP to the wellhead.

in offshore drilling, a tool that seats in a housing at the top of the conductor casing to support subsea equipment and subsequent casing strings and tubing hangers.

the price received by the producer for sales at the well. See crude oil average domestic first purchase price.

War Emergency Pipelines.

crude oil produced from the Permian Basin of West Texas and eastern New Mexico. Its gravity falls between light and heavy crude oil. It is a “benchmark” crude in that its price is often quoted as a measure of general crude oil prices.

a type of separator often used on drilling or workover rigs to separate gas from mud and other liquids returning from the well. It is so called because the first types of this separator were fabricated in the oilfields of West Texas.

see oil-bath air cleaner.

a stage with a dome on top that is open at the bottom, allowing a diver to insert his or her head inside a dry environment.

in pipeline construction, a boring technique similar to slick boring that is used for small-diameter pipe such as natural gas distribution lines. Water is the lubricant. Compare slick boring.

see mud box.

a secondary cell in which the electrolyte is a dilute acid.

the simultaneous or alternate injection of water and air into a formation during an in situ combustion operation. The water reduces heat loss by transmitting heat that would otherwise be left behind in the formation, reduces the amount of required air, and increases the rate of advance of the fire flood. Also called cofcaw (combination of forward combustion and waterflooding). Compare dry combustion.

in paint technology, the thickness of a coat of paint immediately after it is applied and before any solvents in the paint have evaporated.

foam in which the maximum amount of water or other liquid has been added. Compare dry foam. See foam.

1. a gas containing water, or a gas that has not been dehydrated. 2. a rich gas.

glycol that has absorbed water.

said of a job in which tubing is pulled full of oil or water.

a summer monsoon that exhibits heavy rainfall.

a well stream containing mostly natural gas but with enough heavier hydrocarbons in it that it liquefies at surface temperature and pressure.

an oil that contains water, either as an emulsion or as free water.

a still that uses steam vapor to act as a stripping medium. Compare dry still. See still.

a diving suit, usually made of neoprene material, designed to provide thermal insulation for a diver’s body. A small amount of water enters the suit, is warmed by body heat, and protects divers for a short time.

a Christmas tree installed below the water’s surface, which is exposed to the surrounding water. Compare dry tree. See Christmas tree.

underwater welding performed without the use of a protective habitat.

an open tank prover with a gauge glass on the bottom of the prover. Compare dry-bottom prover.

a thermometer whose bulb is covered with a cloth, usually muslin or cambric, saturated with water. It is used to measure relative humidity.

land or areas containing much soil moisture. Wetland areas include areas that support vegetation typically found in saturated soils; that are saturated, flooded, or ponded enough during the growing season to result in an absence of oxygen in their upper parts; or that are subject to wetland hydrology, which results in saturated soil conditions on at least a seasonal basis.

the relative affinity between individual grains of rock and each fluid that is present in the spaces between the grains. If oil and water are both present, the water is usually in contact with the surface of each grain, and the rock is called water-wet. If, however, the oil contacts the surface, the rock is called oil-wet.

the adhesion of a liquid to the surface of a solid.

see surfactant.

the liquid in a two-liquid system that is attracted to the sides of the pore. See nonwetting phase.

a film of water that sticks to, or is adsorbed by, the solid rock material surrounding the pore spaces.

white; used in drilling reports.

in electronics, a special circuit that converts variable resis­tance from a sensing element into a proportional voltage. Output voltage can be calibrated in units of pressure, temperature, or other process variables; or output voltage can be modified to produce a proportional current output for control or indication.

a ditching machine for pipeline construction that has a large, rapidly rotating set of toothed scoops that lift dirt out of the ditch and feed it onto a conveyor mounted on the side of the machine. The wheel ditcher is used almost exclusively for ditching operations in stable soil.

a wheel-shaped wrench that is attached to the sucker rod string at the surface and is manually turned to unscrew the string to allow it to be pulled from the well. Also called a back-off wheel or a circle wrench.

(nautical) a sprocket tooth in a wildcat.

see heat a connection.

secondary hoist line.

oscillation along the longitudinal axis of the drill stem.

a long steel casing that uses an inclined plane to cause the bit to deflect from the original borehole at a slight angle. Whipstocks are sometimes used in controlled directional drilling, in straightening crooked boreholes, and in side tracking to avoid unretrieved fish.

a special-purpose packer placed in the casing to permit a sidetrack operation.

see bit whirl.

a wave with a white, foamy top.

in the Beaufort wind scale, a wind whose speed is from 48 to 55 knots (55 to 63 miles per hour or 89 to 101 kilometres per hour).

all the components of the drilling mud, including reactive and nonreactive solids and the liquid phase (filtrate).

of or having wickers. Also called birdcaged.

broken or frayed strands of the steel wire that makes up the outer wrapping of wire rope.

a shackle which, due to the shape of its bow, is intended for connection or use of wire soft eyes, minimizing damage to the eye.

an orifice chart where the differential and static pressure recordings indicate a wide range of pressure readings.

(slang) on offshore drilling tender rigs, which feature a barge moored to a platform on which the wells are drilled, a narrow walkway placed between the barge and the platform that allows the crew to move between the two.

the seismic drawing (trace) from an instrument that detects, measures, and determines the direction of small electric currents (a galvanometer). The trace shows the wave-form of the recorded data and is called a variable-area display with wiggle.

a well that has blown out of control and from which oil, water, or gas is escaping with great force to the surface. Also called a gusher.

1. a well drilled in an area where no oil or gas production exists. 2. (nautical) the geared sheave of a windlass used to pull anchor chain. v: to drill wildcat wells.

see wildcat.

one who drills wildcat wells.

a tropical cyclone in Australia.

1. a machine that pulls or hoists by winding a cable around a spool. 2. a device used to store, heave in, and pay out mooring wire on a rig. 3. a machine that winds wire rope off and onto a storage drum, using a brake to control the speed of unwinding the wire rope.

a weather phenomenon created by unequal heating of the earth’s surface and which is characterized by movement of the earth’s atmosphere. Wind is observable by its effect on objects it contacts-for example, it causes tree branches to move and flags to wave.

on a weather map, a symbol used to show the direction and wind speed at a specific location on the map. A dot at the base of the symbol indicates the location of the observation. One straight line (a shaft) goes out from the dot to indicate the wind’s direction; short angular lines (feathers) and a blacked-in triangle (for the highest wind speeds) on the shaft indicate wind speed.

see wind ring.

the wireline attached to ground anchors to provide lateral support for a mast or derrick. Compare load guy line.

diagram that plots wind direction and speed at a particular location.

short-period waves formed by the contact of wind on the ocean surface.

a specification used to indicate the resistance of a derrick to the force of wind. The wind-load rating is calculated according to API specifications. Typical wind resistance in derricks is 75 miles per hour with pipe standing in the derrick and 115 miles per hour or higher without.

something that breaks the force of the wind. For example, canvas windbreaks installed around the outside of the rig floor on a drilling or workover rig afford the crew protection from strong, cold winds. Sometimes called a prefab.

a federal excise tax on crude oil. It has a different rate for oil in a number of categories, for example, newly discovered oil, stripper oil, and stripper oil produced by independents. The tax rate is determined as a percentage-for instance, at 25%-of the difference between a base price and a market price. There are a variety of exceptions and exemptions; interested parties should query the IRS or a tax accountant.

a set of conductors installed to form the current-carrying element of a dynamo or a stationary transformer.

1. a device on an anchor-handling boat that propels the anchor chain to and from a chain locker, where it is stored. 2. an early hoist or winch which was a simple drum, or spool, sitting horizontally between two posts with one end of a rope attached.

1. a slotted opening or a full section removed in the pipe lining (casing) of a well, usually made to permit sidetracking. 2. a period during which an operation or action can be carried out, such as the drilling window that occurs in offshore Arctic areas in summer or winter.

the openings in the casing from where the laterals are constructed, as in a multilateral well.

(nautical) upwind, i.e., the direction from which the wind is blowing. Also the side of a rig that is exposed to the effects of wind and waves (also known as upwind).

a horizontal pipe that exits from one or two sides of a Christmas tree.

a valve on the wing of a Christmas tree. See wing.

a circular rubber device with a split in its side that is put around drill pipe to wipe or clean drilling mud off the outside of the pipe as the pipe is pulled from the hole.

a rubber-bodied, plastic- or aluminum-cored device used to separate cement and drilling fluid as they are being pumped down the inside of the casing during cementing operations. A wiper plug also removes drilling mud that adheres to the inside of the casing.

in an anchoring system for semisubmersible rigs working in deep water, the strong cable (wire), one end of which is connected to a winch and the other end of which is attached to the end of the anchor’s chain. By combining wire and chain, instead of using all chain, to create the length necessary to successfully anchor a semisubmersible in deep water, the anchoring system’s weight and the storage space required for the anchoring system is reduced. (If only chain was used, the space needed to store the chain on board the rig while the anchors were not being used would be so large as to be impractical.)

a cable composed of steel wires twisted around a central core of fiber or steel wire to create a rope of great strength and considerable flexibility. Wire rope is used as drilling line (in rotary and cable-tool rigs), coring line, servicing line, winch line, and so on. It is often called cable or wireline; however, wireline is a single, slender metal rod, usually very flexible. Compare wireline.

the center part of a wire rope construction which may be a bundle of wires or fiber.

see drilling line.

a special clamp that temporarily joins the end of two lengths of wire rope. See swivel-type stringing grip.

a bundle of wires that comprise part of a wire rope construction.

a device that secures the end of a bend in the wire rope to the body of the wire rope. A typical safety clamp consists of a U-shaped bolt that is fastened to the wire rope with a saddle-shaped base. Two nuts on the base thread onto the U-bolt to secure the clamp to the rope. Depending on the diameter of the wire rope, which determines the amount of rope that is looped back on itself to secure the rope to the tongs or other device, clamps can vary in number from one to three.

a resistor made from special wire, usually Nichrome, that is wound around a relatively small cylindrical core or tube. Wire-wound resistors can handle large amounts of power and maintain their ohmic value even under high temperatures.

a relatively short length of pipe that has openings in its sides and a specially shaped wire wrapped around the pipe. It is used in wire-wrapped screen completions, usually in conjunction with a gravel pack. The screen and gravel pack block out sand and allow fluids to flow into the well through the openings in the screen. Also called a screen liner.

a slender, rodlike or threadlike piece of metal usually small in diameter, that is used for lowering special tools (such as logging sondes, perforating guns, and so forth) into the well. Also called slick line. Compare wire rope.

a device containing a valve that closes around the wire­line to shut in the well if high pressure threatens a blowout. Also called a wireline valve.

see core barrel.

a coring method in which a core barrel assembly is lowered through the drill pipe on wireline without tripping out the drill pipe. After the core is drilled, the core and the core barrel are retrieved by an overshot assembly.

a device usually run on a solid wireline to cut another wireline stuck in a well.

see electric logging.

a flared-end sub run on the end of the tubing string to permit easy access of wireline tools into the tubing ID.

a tool used to gouge and clean junk and debris from the casing in conjunction with a junk catcher.

a formation fluid sampling device, actually run on conductor line rather than wireline, that also logs flow and shut-in pressure in rock near the borehole. A spring mechanism holds a pad firmly against the sidewall while a piston creates a vacuum in a test chamber. Formation fluids enter the test chamber through a valve in the pad. A recorder logs the rate at which the test chamber is filled. Fluids may also be drawn to fill a sampling chamber. Wireline formation tests may be done any number of times during one trip in the hole, so they are very useful in formation testing.

a tool used to fish broken wireline out of tubing. Two or three barbed prongs extend along the inside of the U-shaped housing. Wireline becomes caught on these prongs and can be retrieved.

any log that is run on wireline.

see well logging.

the lowering of mechanical tools, such as valves and fishing tools, into the well for various purposes. Electric wireline operations, such as electric well logging and perforating, involve the use of conductor line, which in the oil patch is commonly but erroneously called wireline.

a special container that holds a pressure-sensing device and a recorder that is run into and retrieved from a well on wireline to measure and record pressures in the well.

a manually operated ram preventer especially adapted for closure around a wireline.

a diagnostic tool used to ascertain the position of a gas leak in the tubing of a gas-lift well.

the smallest rig that raises and lowers a wireline or conductor line.

a general term used to refer to any servicing operation using a wireline.

the connection used to attach wireline to the tool string. The wireline socket contains a rotating disk to allow the tool string to swivel horizontally and a small spring to cushion the line and to prevent the line from breaking during heavy operations. See wireline tool string.

a special fishing tool fitted with prongs to catch and recover wireline that has broken off and been left in a well.

a stuffing box and lubricator used with wireline during a bottomhole pressure test. See lubricator, stuffing box.

a general term often used to refer to any type of log being run in a well.

the string of tools and equipment that is attached to conductive or nonconductive wireline and lowered downhole to perform wireline operations.

special tools or equipment made to be lowered into and retrieved from the well on a wireline, e.g., packers, swabs, gas-lift valves, measuring devices.

a service vehicle or unit on which the spool of wireline is mounted for use in downhole wireline work.

equipment in which wireline is transported and stored and used to perform a particular operation on a well that employs a tool that can be run on wireline. Wireline units range from logging trucks, which lower logging tools into and out of the wellbore on wireline, to equipment rigged up on a well that allows tools to be lowered into and out of the well on wireline. See wireline, wireline operations.

see wireline blowout preventer.

the recording of subsurface characteristics by wireline (actually conductor line) tools. Wireline well logs include acoustic logs, caliper logs, radioactivity logs, magnetic resonance logs, and resistivity logs.

a flexible rubber wiper used to scrape mud or oil from a wireline as it is pulled from a hole.

a workover performed with wireline lowered into the well through the tubing string. A lubricator is rigged up over the wellhead and wireline tools are inserted through the lubricator under pressure. A variety of wireline tools is available.

World Meteorological Organization.

waiting on orders; used in drilling reports.

weight on bit.

a number proportional to the heat input into a burner at constant pressure.

movement between the mating surfaces of box and pin in a tool joint. v: to move in a rocking motion.

waiting on cement; used in drilling reports.

waiting on engineering.

water-oil-gas.

see methanol.

water-oil ratio.

the acting of a force through distance, or the overcoming of a resistance to motion. No work is done unless motion is produced. Mathematically, work is force times distance.

see personnel basket.

a boat or self-propelled barge used to carry supplies, tools, and equipment to a job site offshore.

hardness developed in metals as a result of cold-working.

to perform one or more of a variety of remedial operations on a producing oilwell to try to increase production. Examples of workover operations are deepening, plugging back, pulling and resetting liners, and squeeze cementing.

an underwater location where work is performed.

1. in drilling, the string of drill pipe or tubing suspended in a well to which is attached a special tool or device that is used to carry out a certain task, such as squeeze cementing or fishing. 2. in pipeline construction, the string of washpipe that replaces the pilot string in a directionally drilled river crossing. The work string remains in place under the river until the actual pipeline is made up and is ready to be pulled back across the river.

a larger type of self-contained breathing gear that provides from 30 to 60 minutes of air. This apparatus differs from the emergency escape unit mainly in the size of the air bottle and, hence, in its capacity to store air. Compare emergency escape unit.

a form of insurance that provides medical care for employees who are injured on the job; in exchange for being compensated for medical care, the employee must give up his or her right to sue the employer for negligence.

the outer shell of a downhole plunger pump. The pumping cycle starts with an upward stroke of the rods, which pulls the plunger up through the working barrel. On the upstroke, the traveling valve closes, the standing valve in the working barrel opens, fluid above the traveling valve is lifted out of the well, and a new charge is drawn into the pump. On the downstroke, the traveling valve opens, the standing valve closes, and the fluid is forced from the working barrel through the traveling valve in the plunger and into the tubing. Repeated strokes bring the fluid to the surface.

refrigerant coolant material.

the volume of gas in an underground storage reservoir above the designed level of the base. It may or may not be completely withdrawn during any particular withdrawal season.

the interest in oil or gas that includes responsibility for all drilling, developing, and operating costs. Also called leasehold interest, operating interest.

1. the maximum pressure at which an item is to be used at a specified temperature. 2. the current pressure functioning in a process.

a standard that is calibrated against a reference standard and is intended to verify working measuring instruments of lower accuracy. Compare primary standard, secondary standard.

see work string.

the measuring tape used to measure all of a tank’s rings after it is calibrated to the standard tape. See standard tape, strapping.

see net production, working interest.

the performance of one or more of a variety of remedial operations on a producing oilwell to try to increase production. Examples of workover jobs are deepening, plugging back, pulling and resetting liners, and squeeze cementing. See recompletion.

a special drilling mud used to keep a well under control while it is being worked over. A workover fluid is compounded carefully so that it will not cause formation damage.

a portable rig used for working over a well. See production rig.

a United Nations agency that was formed to promote international cooperation in all aspects of meteorological activities. Address: Case Postale 2300, CH-1211, Geneva 2, Switzerland.

1. a new and inexperienced worker on a drilling rig. 2. a short revolving screw with spiral-shaped threads.

the gear of a worm and a worm wheel working together.

a toothed wheel gearing the thread of a worm.

see subgeologic map.

the worst possible spill from a vessel or facility. Such a spill is determined by the maximum amount of discharge possible from the facility, or the total release of a full cargo from the firm’s largest vessel, in the worst weather conditions.

waiting on weather.

a flat area on an otherwise round fitting to which a wrench can be applied (as on sucker rod coupling). Also called a wrench square.

see wrench flat.

in an engine, the hard steel, hollow cylinder that attaches the piston to the piston rod. A circular opening in the piston is lined up with a corresponding circular opening in the rod and the wrist pin is pushed through the openings. Usually, special keys on each end of the pin lock the pin in the piston. Also called piston pin.

West Texas intermediate.

a three- or four-wire connection, resembling the letter Y, used in three-phase circuits alone or in various combinations with delta connections.