Oil & Gas Glossary 1.0

The amount of pressure exerted inside the drill pipe as a result of circulating pressure, entry of formation pressure into the well, or both.

An indicator, mounted in the mud circulating system, that measures and indicates the amount of pressure in the drill stem. See drill stem.

The column, or string, of drill pipe with attached tool joints that transmits fluid and rotational power from the kelly to the drill collars and bit. Often, especially in the oil patch, the term is loosely applied to both drill pipe and drill collars. Compare drill stem.

The column, or string, of drill pipe with attached tool joints that transmits fluid and rotational power form the kelly to the drill collars and bit. Often, especially in the oil patch, the term is loosely applied to both drill pipe and drill collars. Compare drill stem.

A short, threaded piece of pipe used to adapt parts of the drilling string that cannot otherwise be screwed together because of differences in thread size or design. A sub (i.e., a substitute) may also perform a special function. Lifting subs are used with drill collars to provide a shoulder to fit the drill pipe elevators; a kelly saver sub is placed between the drill pipe and the kelly to prevent excessive thread wear of the kelly and drill pipe threads, a bent sub is used when drilling a directional hole.

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. the amount of pressure indicated by a drill pipe pressure gauge when drilling fluid is being circulated by the mud pump. Pressure losses occur as the fluid is circulated.

Seamless steel or aluminum pipe made up in the drill stem between the kelly or top drive on the surface and the drill collars on the bottom. During drilling, it is usually rotated while drilling fluid is circulated through it. Drill pipe joints are available in three ranges of length: 18 to 22 feet, 27 to 30 feet, and 38 to 45 feet. The most popular length is 27 to 30 feet. It is available with outside diameters ranging from 2 7/8 to 5 1/2 inches. Several joints are made up (screwed together) to form the drill string.

A cast-iron or magnesium drillable tool consisting of a packing assembly and a back-pressure valve. It is used to close off the annular space between tubing or drill pipe and casing to allow the placement of cement or fluid through the tubing or drill pipe at any predetermined point behind the casing or liner, around the shoe, or into the open hole around the shoe.

Drill pipe, drill collars, casing, or tubing that has inadvertently become immovable in the hole. Sticking may occur when drilling is in progress, when casing is being run in the hole, or when the drill pipe is being hoisted.

The act of ensuring that a pipe ram preventer will not close on a drill pipe tool joint when the drill stem is stationary. A pup joint is made up in the drill string to lengthen it sufficiently.

Pressure of the annular fluid on the casing at the surface when a well is shut in.

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

All members in the assembly used for rotary drilling from the swivel to the bit, including the kelly, drill pipe and tool joints, drill collars, stabilizers, and various specialty items. Compare drill string.

All members in the assembly used for rotary cutting from the swivel to the ball, including the kelly, drill pipe and tool joints, drill collars, stabilizers, and various specialty items. Compare drill string.

A dart-shaped drill pipe inside blowout preventer installed on top of the drill stem when the well is kicking through the drill stem. It is stabbed in open then closed against pressure.

Abbreviation: shut-in drill pipe pressure, used in drilling reports.

1. to force pipe or tools into a high-pressure well that has not been killed (i.e., to run pipe or tools into the well against pressure when the weight of pipe is not great enough to force the pipe through the BOPs). Snubbing usually requires an array of wireline bocks and wire rope that forces the pipe or tools into the well through a stripper head or blowout preventer until the weight of the string is sufficient to overcome the lifting effect of the well pressure on the pipe in the preventer. In workover operations, snubbing is usually accomplished by using hydraulic power to force the pipe through the stripping head or blowout preventer.

To place stands of drill pipe and drill collars in a vertical position to one side of the rotary table in the derrick or mast of a drilling or workover rig. Compare lay down pipe.

The component in a blowout preventer that cuts, or shears, through drill pipe and forms a seal against well pressure. Shear rams are used in floating offshore drilling operations to provide a quick method of moving the rig away from the hole when there is no time to trip the drill stem out of the hole.

A single length (30 feet or 9 meters) of drill pipe, drill collar, casing, or tubing that has threaded connections at both ends. Several joints screwed together constitute a stand of pipe.

A small mud tank with a capacity of 10 to 15 barrels, usually with 1-barrel or H-barrel divisions, used to ascertain the amount of mud necessary to keep the wellbore full with the exact amount of mud that is displaced by drill pipe. When the bit comes out of the hole, a volume of mud equal to that which the drill pipe occupied while in the hole must be pumped into the hole to replace the pipe. When the bit goes back in the hole, the drill pipe displaces a certain amount of mud, and a trip tank can be used again to keep track of this volume.

A heavy, thick-walled tube, usually steel, used between the drill pipe and the bit in the drill stem to provide a pendulum effect to the drill stem and weight to the bit.

The closing and sealing component on a blowout preventer. One of three types--blind, pipe, or shear--may be installed in several preventers mounted in a stack on top of the wellbore. Blind rams, when closed, form a seal on a hole that has no drill pipe in it; pipe rams, when closed, seal around the pipe; shear rams cut through drill pipe and then form a seal.

The pressure in a well between the casing and the tubing or the casing and the drill pipe.

A heavy coupling element for drill pipe. It is made of special ahoy steel and has coarse, tapered threads and seating shoulders designed to sustain the weight of the drill stem, withstand the strain of frequent coupling and uncoupling, and provide a leakproof seal. The male section of the joint, or the pin, is attached to one end of a length of drill pipe, and the female section, or box, is attached to the other end. The tool joint may be welded to the end of the pipe, screwed on, or both. A hard-metal facing is often applied in a band around the outside of the tool joint to enable it to resist abrasion from the walls of the borehole.

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 differential-pressure sticking, or wall sticking, are a permeable formation and a pressure differential across a nearly impermeable filter cake and drill stem. Also called wall sticking. See differential pressure, filter cake.

A long, hollow cylinder, usually steel, through which fluids are conducted. Oilfield tubular goods are casing (including liners), drill pipe, tubing, or line pipe

N: a collar or coupling of tool steel, threaded internally, that can be used to retrieve pipe from the well on fishing jobs; the female counterpart of a taper tap. The die collar is made up on the drill pipe and lowered into the hole until it contacts the lost pipe. If the lost pipe is stuck so that it cannot rotate, rotation of the die collar on top of the pipe cuts threads on the outside of the pipe, providing a firm attachment. The pipe is then retrieved from the hole. Compare taper tap. It is not often used because it is difficult to release it from the fish should it become necessary.

To pump a quantity of heavy mud into the drill pipe. Before hoisting drill pipe, it is desirable (if possible) to pump into its top section a quantity of heavy mud (a slug) that causes the level of the fluid to remain below the rig floor so that the crew members and the rig floor are not contaminated with the fluid when stands are broken out.

A preventer having a unit of packing material whose closure depends on well pressure coming from below. It is used primarily to strip pipe through the hole or allow pipe to be moved with pressure on the annulus.

A special valve installed below the kelly. Usually, the valve is open so that drilling fluid can flow out of the kelly and down the drill stem. It can, however, be manually closed with a special wrench when necessary. In one case, the valve is closed and broken out, still attached to the kelly to prevent drilling mud in the kelly from draining onto the rig floor. In another case, when kick pressure inside the drill stem exists, the drill stem safety valve is close to prevent the pressure from escaping up the drill stem.

To use a whipstock, turbodrill, or other mud motor to drill around broken drill pipe or casing that has become lodged permanently in the hole.

2. To remove the settlings and cavings that are plugged inside a hollow fish (such as drill pipe) during a fishing operation.

The large wrenches used to make up or break out drill pipe, casing, tubing, or other pipe; variously called casing tongs, pipe tongs, and so forth, according to the specific use. Power tongs are pneumatically or hydraulically operated tools that serve to spin the pipe up tight and, in some instances, to apply the final makeup torque.

The pressure lost in a pipeline or annulus due to the velocity of the liquid in the pipeline, the properties of the fluid, the condition of the pipe wall, and the alignment of the pipe. In certain mud-mixing systems, the loss of head can be substantial

Any kind of pipe. Oilfield tubular goods include tubing, casing, drill pipe, and line pipe. Also called tubulars.

A fishing tool that is attached to tubing or drill pipe and lowered over the outside wall of pipe or sucker rods lost or stuck in the wellbore. A friction device in the overshot, usually either a basket or as spiral grapple, firmly grips the pipe, allowing the fish to be pulled from the hole.

A reduction in the pressure of a fluid caused by its motion against an enclosed surface (such as a pipe). As the fluid moves through the pipe, friction between the fluid and the pipe wall and within the fluid itself creates a pressure loss. The faster the fluid moves, the greater are the losses.

The pressure generated by the mud pumps and exerted on the drill stem

Unscrewing the drill stem into single joints and placing them on the pipe rack. The operation takes place on completion of the well, or in changing from one size of pipe to another.

2. a valve installed at the top of the drill stem to prevent flow out of the drill pipe if a kick occurs during tripping operations.

A process used to repair a hole in the casing by pumping cement down tubing or drill pipe. First, the casinghead, or bradenhead, is closed to prevent fluids from moving up the casing. Then the rig's pumps are started. Pump pressure moves the cement out of the tubing or pipe and, since the top of the casing is closed, the cement goes into the hole in the casing. The tubing or pipe is pulled from the well and the cement allowed to harden. The hardened cement seals the hole in the casing. Although the term "bradenhead squeezing" is still used, the term "bradenhead" is obsolete. See annular space, casinghead, squeeze.

The pressure at which a well is circulated during well-killing procedures after killweight mud has filled the drill stem. This pressure is maintained until the well is completely filled with killweight mud.

A sudden, usually short-duration, increase in pressure. When pipe or casing is run into a hole too rapidly, an increase in the hydrostatic pressure results, which may be great enough to create lost circulation

To take rams out of a blowout preventer and replace them with rams of a different size or type. When the size of a drill pipe is changed, the size of the pipe rams must be changed to ensure that they seal around the pipe when closed (unless variable-bore pipe rams are in use).

1. the process of lowering the drill stem into the wellbore when the well is shut in on a kick and when the weight of the drill stem is sufficient to overcome the force of well pressure.

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

1. a rubber disk surrounding drill pipe or tubing that removes mud as the pipe is brought out of the hole.

The connected joints of pipe racked in the derrick or mast during a trip. The usual stand is about 90 feet long (about 27 meters), which is three lengths of drill pipe screwed together (a thribble).

To attach a joint of drill pipe onto the drill stem suspended in the wellbore to permit deepening the wellbore by the length of the joint added (about 30 feet, or 9 meters).

Heavy seamless tubing used to rotate the bit and circulate the drilling fluid. Joints of pipe approximately 30 feet (9 meters) long are coupled together by means of tool joints.

The conventional method of formation testing. The basic drill stem test tool consists of a packer or packers, valve or ports that may be opened and closed from the surface, and two or more pressure-recording devices. The tool is lowered on the drill string to the zone to be tested. The packer or packers are set to isolate the zone from the drilling fluid column. The valves or ports are then opened to allow for formation flow while the recorders chart static pressures. A sampling chamber traps dean formation fluids at the end of the test. Analysis of the pressure charts is an important part of formation testing.

A method of severing steel pipe in a well by applying high-pressure jets of a very corrosive substance against the wall of the pipe. The resulting cut is very smooth.

The pipe and special fittings used on floating offshore drilling rigs to establish a seal between the top of the wellbore, which is on the ocean floor, and the drilling equipment, located above the surface of the water. A riser pipe serves as a guide for the drill stem from the drilling vessel to the wellhead and as a conductor of drilling fluid from the well to the vessel. The riser consists of several sections of pipe and includes special devices to compensate for any movement of the drilling rig caused by waves. It is also called a marine riser.

A drilling method in which a hole is drilled by a rotating bit to which a downward force is applied. The bit is fastened to and rotated by the drill stem, which also provides a passageway through which the drilling fluid is circulated. Additional joints of drill pipe are added as drilling progresses.

The heavy steel member, three-, four-, six-, or eight-sided, suspended from the swivel through the rotary table and connected to the topmost joint of drill pipe to turn the drill stem as the rotary table turns. It has a bored passageway that permits fluid

A method of stimulating production by opening new flow channels in the rock surrounding a production well. Often call a frac job. Under extremely high hydraulic pressure, a fluid (such as distillate, diesel fuel, crude oil, dilute hydrochloric acid, water, or kerosene) is pumped downward through production tubing or drill pipe and forced out below a packer or between two packers. The pressure causes cracks to open in the formation, and the fluid penetrates the formation through the cracks. Sand grains, aluminum pellets, walnut shells, or similar materials (propping agents) are carried in suspension by the fluid into the cracks. When the pressure is released at the surface, the fracturing fluid returns to the well. The cracks partially close on the pellets, leaving channels for oil to flow around them to the well. See explosive fracturing, hydraulic fracturing.

A special mill that has a heavy tubular extension below it called a pilot or stinger. The pilot, smaller in diameter than the mill, is designed to go inside drill pipe or tubing that is lost in the hole. It guides the mill to the top of the pipe and centers it, thus preventing the mill from bypassing the pipe. Also called a piloted mill.

To pass from one point throughout a system and back to the starting point. For example, drilling fluid is circulated out of the suction pit, down the drill pipe and drill collars, out the bit, up the annulus, and back to the pits while drilling proceeds.

An explosive method utilizing primacord, which is an instantaneous textile-covered fuse with a core of very high explosive. It is used to create an explosive jar inside st5uck drill pipe or tubing so that the pipe may be backed off at the joint immediately above where it is stuck.

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

An area of reduced diameter in pipe caused by excessive longitudinal strain or by a combination of longitudinal string and the swagging 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.

The lowest internal pressure at which a failure (of pipe) will take place.

A vessel used to bury pipeline beneath the seafloor. The barge moves itself forward by means of anchors. A jet sled is lowered over the pipeline, and as the barge pulls it over the pipe, high-pressure jets of water remove soil from beneath the pipe, allowing the pipe to fall into the jetted-out trench.

An opening at floor level in a side of a derrick or mast. The V-door is opposite the drawworks and is used as an entry to bring in drill pipe, casing, and other tools from the pipe rack. The name comes from the fact that on the old standard derrick, the shape of the opening was an inverted V.

2. of a hole, having no drill pipe or tubing suspended in it.

Oil-well, casing, tubing, or drill pipe.

A joint of drill pipe. Compare double, thribble, and fourable.

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.

The cutting or boring element used in drilling oil and gas wells. This bit consists of a cutting element and a circulating element. The circulating element permits the passage of drilling fluid and utilized 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 string of drill collars. Most bits used in rotary drilling are roller cone bits, but diamond bits are also used extensively.

The depth in the hole at which the tubing, casing, or drill pipe is stuck.

A downhole tool with rough, sharp, extremely hard cutting surfaces for removing metal by grinding or cutting. Mills are run on drill pipe or tubing to grind up debris in the hole, remove stuck portions of drill stem or sections of casing for sidetracking, and ream out tight spots in the casing. They are also called junk mills, reaming mills, and so forth, depending on what use they have.

To measure drill pipe or tubing as it is pulled out of the hole, usually to determine the depth of the well or the depth to which the pipe or tubing was run.

A length of drill or line pipe, tubing, or casing considerably shorter than 30 feet.

To obtain an accurate measurement of the depth reached in a well by measuring the drill pipe or tubing as it is run into the well.

A hydraulically powered device used in lieu of a rotary to turn the drill pipe, tubing, or casing in a well.

A device in a rotary table or other tool into which tubing, drill pipe, or slips can be inserted.

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

2. to remove the settlings and cavings that are plugged inside a hollow fish (such as drill pipe) during a fishing operation.

A section of drill pipe, casing, or tubing consisting of four joints screwed together. Compare double, single, thribble.

Equipment operated hydraulically or by compressed air for making up and breaking out drill pipe, casing, tubing, and rods.

A drillable tool configuration allowing the opening of formation pressure, during drillout, prior to cutting through the tools slips.

2. to pull formation fluids into a wellbore by raising the drill stem at a rate that reduces the hydrostatic pressure of the drilling mud below the bit.

An instrument that measures fluid pressure and usually registers the difference between atmospheric pressure and the pressure of the fluid by indicating the effect of such pressures on a measuring element (e.g., a column of liquid, pressure in a Bourdon tube, a weighted piston, or a diaphragm).

The force that a fluid (liquid or gas) exerts uniformly in all directions within a vessel, pipe, hole in the ground, and so forth, such as that exerted against the inner wall of a tank or that exerted on the bottom of the wellbore by a fluid. Pressure is expressed in terms of force exerted per unit of area, as pounds per square inch, or in kilopascals.

A device made up in the drill string that, when actuated, delivers a heavy downward blow to the string. A bumper jar has a hollow body that moves upward when the drill string is picked up. When the string is dropped quickly, the jar body produces a sharp downward blow on the tubing or pipe made up below the jar. If downward blows can free a fish, a bumper jar can be very effective.

A rapid increase in n pressure downhole that occurs when the drill stem is lowered too fast or when the mud pump is brought up to speed after starting.

A sudden increase in the drill bit's rate of penetration. it sometimes indicates that the bit has penetrated a high-pressure zone and thus warns of the possibility of a kick.

Pressure exceeding or falling below the normal pressure to be expected at a given depth. Normal pressure increases approximately 0.465 psi per foot of depth (10.5kPa per meter of depth). Thus, normal pressure at 10,000 feet is 4,650 psi; abnormal pressure at this depth would be higher or lower than 4,650 psi. See pressure gradient.

A sealing device used to close off the annular space around the kelly in drilling with pressure at the surface, usually installed above the main blowout preventers. A rotating head makes it possible to drill ahead even when there is pressure in the annulus that the weight of the drilling fluid is not overcoming; the head prevents the well from blowing out. It is used mainly in the drilling of formations that have low permeability. The rate of penetration through such formations is usually rapid.

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

Drill pipe, tubing, sucker rods, and so forth with the diameter near the top of the well larger than the diameter below.

1. a device that mechanically or hydraulically forces pipe or tools into the well against pressure.

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

The smaller of the side fittings on a bell nipple, used to fill the hole when drill pipe is being removed from the well.

A large, hook-shaped device from which the swivel is suspended. It is designed to carry maximum loads ranging from 100 to 650 tons (90 to 590 tonnes) and turns on bearings in its supporting housing. A strong spring within the assembly cushions the weight of a stand (90 feet, about 27 meters) of drill pipe, thus permitting the pipe to be made up and broken out with less damage to the tool join threads. Smaller hooks without the spring are used for handling tubing and sucker rods. See stand and swivel.

A device run on wireline into the wellbore and inside the fishing string and fish to locate the area where a fish is stuck. When the drill string is pulled and turned, the electromagnetic fields of free pipe and stuck pipe differ. The free-point indicator is able to distinguish these differences, which are registered on a metering device at the surface.

A tubular device, usually from 10 to 60 feet (3 to 18 meters) long, run at the bottom of the drill pipe in place of a bit and used to cut a core sample.

A bentonite and diesel oil mixture that is pumped down the drill pipe and into the annulus to mix with drilling mud. The stiff, putty-like material is squeezed into lost circulation zones to seal them.

The average pressure within the reservoir at any given time. Determination of this value is best made by bottomhole pressure measurements with adequate shut-in time. If a shut-in period long enough for the reservoir pressure to stabilize is impractical, then various techniques of analysis by pressure buildup or drawdown tests are available to determine static reservoir pressure.

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.

Clamps that grip a stand of casing, tubing, drill pipe, or sucker rods so that the stand can be raised or lowered into the hole.

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 method of determining the amount of pressure that is allowed to appear on the casing pressure gauge as a kick is circulated out of a well. In general, it is determined by slowly pumping mud into the well while it is shut in and observing the pressure at which the formation begins to take mud.

A circular steel device that holds slips supporting a suspended string of drill pipe, casing, or tubing. A spider may be split or solid.

An assembly of tools made up on drill pipe that is lowered into the hole to retrieve lost or stuck equipment. Also call a fish assembly.

The string of drill pipe tubing suspended in a well to which is attached a special tool or device that is used to carry out a certain task, as squeeze cementing or fishing.

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.

An accessory attached o the top of the drill pipe or tubing to form a connection with the mud system to permit circulation of the drilling mud. In some cases, it is also a rotating head.

The joint of drill pipe that is used in hang-off operations so that no tool joint is opposite a set of preventer rams.

A complete break in pipe caused by metal fatigue. v: to break something in two or to break apart, such as the head of a bolt or the drill stem.

An area or point above the point at which a tubular, such as drill pipe, is stuck in the wellbore.

A device made up in the drill stem and lowered into the well to allow the casing and blowout preventers to b pressure-tested. The sealing device is cup-shaped and is therefore called a cup.

Total pressure measured from an absolute vacuum. It equals the sum of the gauge pressure and the atmospheric pressure corresponding to the barometer (expressed in pounds per square inch).

A valve installed above the kelly that can be closed manually to protect the rotary hose from high pressure that may exist in the drill stem

1. to move the drill stem up and down in the hole over a short distance without rotation. Careless execution of this operation creates pressure surges that can cause a formation to break down, resulting in lost circulation.

The smooth, uninterrupted circulation of drilling fluid down the drill stem, out the bit, up the annular space between the pipe and the hole, and back to the surface. Compare reverse circulation.

See slips

The action of pull out and subsequently running back into the hole a string of drill pipe or tubing. Making a round trip is also called tripping.

A device attached to the catshaft of the drawworks that is used as a power source for unscrewing drill pipe; usually located opposite the driller's side of the drawworks. See cathead.

The amount of pressure that, when applied inside a string of casing, causes the wall of the casing to fail. This pressure is critically important when a gas kick is being circulated out, because gas on the way to the surface expands and exerts more pressure than it exerted at the bottom of the well.

2. in reference to engines, a term used to describe the resistance to the flow of exhaust gas through the exhaust pipe.

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 the 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.

Total pressure exerted in the wellbore by a column of fluid and/or back-pressure imposed at the surface.

Said of any pressure-tight vessel or container when the internal pressure is lower than atmospheric pressure

1. to recover from a well any equipment left there during drilling operations, such as a lost bit or drill collar or part of the drill string.

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 special nipple made up in the tubing, casing, or drill pipe string the configuration of which is such that a tool contacting it can pass through only if the tool is in the proper position or configuration.

A fishing tool used to retrieve pipe lost in a well. The spear is lowered down the hole and into the lost pipe. When weight, torque, or both are applied to the string to which the spear is attached, the slips in the spear expand and tightly grip the inside of the wall of the lost pipe. Then the string, spear, and lost pipe are pulled to the surface.

2. the change (along a horizontal distance) in atmospheric pressure. Isobars drawn on weather maps display the pressure gradient.

The first string of casing (after the conductor pipe) that is set in a well. it varies in length from a few hundred to several thousand feet. Some states require a minimum length to protect freshwater sands. Compare conductor pipe.

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

The increase in bottomhole pressure expressed as an increase in pressure that occurs only when mud is being circulated. Because of friction in the annulus as the mud is pumped, bottomhole pressure is slightly, but significantly, higher than when the mud is not being pumped. ECD is calculated by dividing the annular pressure loss by 0.052, dividing that by true vertical depth, and adding the result to the mud weight.

The gathering of pressure data and fluid samples from a formation to determine its production potential before choosing a completion method. Testing tools include formation testers and drill stem test tools.

1. to remove with the drill bit the residual cement that normally remains in the lower section of casing and the wellbore after the casing has been cemented.

A blowout preventer that uses pipe rams as the closing elements. See pipe ram.

Repressuring of an oil-field to maintain original pressure. The use of water flooding or natural gas recycling during primary recovery to provide additional formation pressure and displacement energy that can supplement and conserve natural reservoir drives. Although commonly begun during primary production, pressure maintenance methods are often considered to be a form of enhanced oil recovery.

A walled round hole or well in the hull of a drill ship (usually in the center) through which the drilling assembly and other assemblies pass while a well is being drilled, completed, or abandoned from the drill ship.

1. a scale of pressure differences in which there is a uniform variation of pressure from point to point. For example, the pressure gradient of a column of water is about 0.433 pounds per square inch per foot (9.794 kilopascals per meter) of vertical elevation. The normal pressure gradient in a formation is equivalent to the pressure exerted at any given depth by a column of 10 percent salt water extending from that depth to the surface 0.465 pounds per square inch per foot or 10.518 kilopascals per meter).

A part of the brake mechanism consisting of a flexible steel band lined with a material that grips a drum when tightened. On a drilling rig, the brake band acts on the flanges of the drawworks drum to control the lowering of the traveling block and its load of drill pipe, casing, or tubing.

The derrickman's working platform. As pipe of tubing is run into or out of the hole, the derrickman must handle the top end of the pipe, which may be as high as 90 feet (27 m) in the derrick or mast. The monkeyboard provide a small platform to raise him to the proper height for handling the top of the pipe.

A drilling rig that is used exclusively to drill offshore exploration and development wells and that floats upon the surface of the water when being moved from one drill site to another. It may or may not float once drilling begins. Two basic types of mobile offshore drilling units are used to drill most offshore wildcat wells: bottom-supported drilling rigs and floating drilling rigs.

A block with lead or another relatively soft material on its bottom. It is made up of drill pipe or tubing at the surface, run into a well, and set down on the object that has been lost in the well. The block is retrieved and the impression is examined. The impression is a mirror image of the top of the fish and indicates the fish's position in the hole, i.e., whether it is centered or off to one side. From this information, the correct fishing tool can be selected.

A hand tool consisting of a handle and chain that resembles the chain on a bicycle. In general, chain tongs are used for turning pipe or fittings of a diameter larger than that which a pipe wrench would fit. The chain is looped and tightened around the pipe or fitting, and the handle is used to turn the tool so that the pipe or fitting can be tightened or loosened.

Gas that enters the wellbore when the mud pump is shut down and pipe is being pulled from the wellbore. The gas may enter because of the reduction in bottomhole pressure when the pump is shut down, because of swabbing, or because of both.

A blowout preventer that uses rams to seal off pressure on a hole that is with or without pipe. Also called a ram preventer.

A check valve in the drill string that will allow fluid to be pumped into the well but will prevent flow from entering the string.

1. to place pipe withdrawn from the hole on a pipe rack

1. a reduction in the amount of force a fluid exerts against a surface, such as the walls of a pipe. It usually occurs because the fluid is moving against the surface and is caused by the friction between the fluid and the surface.

The difference between two fluid pressures; for example, the difference between the pressure in a reservoir and in a wellbore drilled in the reservoir, or between atmospheric pressure at sea level and at 10,000 feet.

A drilling structure consisting of a barge upon which the drilling equipment is constructed. When moved from one location to another, the barge floats. When stationed on the drill site, the barge can be anchored in the floating mode or submerged to rest on the bottom. Typically, inland barge rigs are used to drill wells in marshes, shallow inland bays, and areas where the water covering the drill site in not too deep. Also called swamp barge. See floating offshore drilling rig.

An 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. The drilling line is reeved over the sheaves of the crown block alternately which the sheaves of the traveling block, which is raised and lowered in the derrick by the drilling line. When elevators are attached to a hook on the traveling block and drill pipe latched in the elevators, the pipe can be raised or lowered. See crown block and traveling block.

To hoist the drill stem out of the wellbore to perform one of a number of operations such as changing bits, taking a core, and so forth, and then to return the drill stem to the wellbore.

To pull the drill stem out of the wellbore to change the bit, to change from a core barrel to the bit, to run electric logs, to prepare for a drill stem test, to run casing, and so on. Also called trip out.

(n) a device with an elastomer packing element that depends on pressure below the packing to effect a seal in the annulus. Used primarily to run or pull pipe under low or moderate pressures. This device is not dependable for service under high differential pressures. Also called a stripper.

Trade name for a downhole motor driven by drilling fluid that imparts rotary motion to a drilling bit connected to the tool, thus eliminating the need to turn the entire drill stem to make hole. Used in straight and directional drilling.

2. to stand pipe on the derrick floor when pulling it out of the hole.

2. a pipe used to exhaust gases from the muffler of an engine to the outside atmosphere.

An auxiliary part (such as a coupling, elbow, tee, or cross) used for connecting lengths of pipe.

A metal or plastic device that is screwed onto or into pipe threads to protect 5them from damage when the pipe is not in use.

A device run on cable-tool drilling line, a service machine, or sand line of a rotary rig to drill up tools, remove downhole debris, and so on.

A tool composed of a mandrel on which are mounted several heavy-duty rollers with eccentric roll surfaces. It is used to restore buckled, collapsed, or dented casing in a well to normal diameter and roundness. Made up on tubing or drill pipe and run into the well to the depth of the deformed casing, the tool is rotated slowly, allowing the rollers to contact all sides of the casing and restore it to roughly its original condition.

A device used to connect long lines of pipe to allow the pipe joints to expand or contract as the temperature rises or falls.

The machine used to impart rotational power to the drill stem while permitting vertical movement of the pipe for rotary drilling. Modern rotary machines have a special component, the rotary or master bushing, to turn the kelly bushing, which permits vertical movement of the kelly while the stem is turning.

A diagnostic tool used to ascertain whether there is a gas leak in the tubing of a gas lift well. If there is a tubing leak, the pressure on the annulus will equal the pressure on the tubing.

A special drill stem valve that, when in open position, allows fluid to flow through it, thus allowing the valve to be stabbed into the drill stem.

A rotary tool that is hung from the rotary hook and traveling block to suspend the drill stem and to permit it to rotate freely. it also provides a connection fore the rotary hose and a passageway of the flow of drilling fluid into the drill stem.

A piece of pipe that has been twisted off inside a female connection; or a short section of material, such as belting or pipe, used to lengthen existing equipment.

2. a device for guiding pipe and lowering it to the water bottom as it is being laid down by a lay barge. It is hinged to permit adjustments in the angle of pipe launch.

A fishing tool containing metal-cutting knives that is lowered into the hole and over the outside of a length of pipe to cut it. The severed part of the pipe can then be brought to the surface.

1. a pipe run in a well blow a packer.

A device to measure bottomhole pressure. See bottomhole pressure bomb.

A pressure-sensing element consisting of a twisted or curved rube of non-circular 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.

1. an automatic valve that opens or closes when an abnormal condition occurs (e.g., a pressure relief valve on a separator that opens if the pressure exceeds the set point, or the shutdown valve at the wellhead that closes if the line pressure becomes too high or too low).

A procedure whereby the formation immediately below the casing shoe is subjected to a pressure equal to the pressure expected to be exerted later by a higher drilling glut density or by the sum of a higher drilling fluid density and back-pressure created by a kick.

1.a high-pressure gas injected into a formation to maintain or restore reservoir pressure.

3. the operating pressure level measured downstream from a measuring device.

1. the pressure maintained on equipment or systems through which a fluid flows.

An equipment's working pressure times a safety factor.

The pressure to which a particular piece of equipment is subjected during normal operations.

The pressure resulting from restriction of full natural flow of oil or gas.

The extent to which the hydrostatic pressure of the mud column exceeds formation pressure.

Commonly referred to as snubbing; running of tool and/or pulling of tubing under well pressure.

The pressure at which a well that has been closed in on a kick is circulated when well-killing procedures are begun

A length of pipe whose bottom edge is serrated or dressed with a hard cutting material and that is run into the wellbore around the outside of stuck casing, pipe, or tubing to mill away the obstruction.

Of or relating to a condition in which pressure in the wellbore is less than the pressure in the formation.

A device for maintaining pressure in a line, downstream from the value.

A loss of pressure that results from friction sustained by a fluid passing through a line, valve, fitting, or other device.

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

A pipe that is perforated and often arranged with a wire wrapping to act as a sieve to prevent or minimize the entry of sand particles into the wellbore. Also called a screen pipe.

2. to lower or raise tools in or out of a well with pressure inside the well. The term comes from the fact that a lubricant (grease) is often used to provide a seal against well pressure while allowing wireline to move in or out of the well.

Pressure at the bottom of a well that is shut in.

Formation fluid pressure equivalent to about 0.465 pounds per square foot of depth from the surface. If the formation pressure is 4,650 pounds per square inch at 10,000 feet, it is considered normal.

A self-propelled floating offshore drilling unit that is a ship constructed to permit a well to e drilled from it. Although not as stable as semisubmersible, drill ships are capable of drilling exploratory wells in deep, remote waters. See floating offshore drilling rig.

A bottomhole pressure test that measures pressure after the well has been shut in for a specified period of time. See bottomhole pressure test.

2. to lower or raise tools in or out of a well with pressure inside the well. The term comes from the fact that a lubricant (grease) is often used to provide a seal against well pressure while allowing wireline to move in or out of the well.

In a well-control operation, closing the BOP without first opening an alternate flow path up the choke line. When the BOP is closed, pressure in the annulus cannot be read on the casing pressure gauge.

A packer equipped with friction blocks or drag springs and slips and designed so that rotation of the pipe unlatches the slips. The friction springs prevent the slips from turning with the pipe and assist in advancing the slips up a tapered sleeve to engage the wail of the outside pipe as weight is put on the packer. Also called a wall-hook packer. See packer.

Prevention of formation fluid flow by maintaining a hydrostatic pressure equal to or greater than formation pressure

Additives that, when added to drilling fluid, lubricate bearing surfaces subjected to extreme pressure.

The ratio between the pressure in the hole and the operating-piston pressure needed to close the rams of a blowout preventer.

The pressure at the bottom of a well when the surface valves on the well are completely closed. It is caused by formation fluids at the bottom of the well.

A device that reduces the pressure or volume of a fluid flowing in a line and maintains the pressure or volume at a specified level.

An event occurring when borehole pressure is of such magnitude that the exposed formation cannot withstand applied pressure.

A method of killing a well that has kicked, in which the choke size is adjusted to maintain a constant casing pressure. This method does not work unless the kick is all or nearly all salt water. if the kick is gas, this method will not maintain a constant bottomhole pressure, because gas expands as it rises in the annulus. In any case, it is not a recommended well-control procedure.

See back-pressure

The force exerted by a body of fluid at rest. It increases directly with the density and the depth of the fluid and is expressed in pounds per square inch or kilopascals. The hydrostatic pressure of fresh water is 0.433 pounds per square inch per foot of depth (9.792 kilopascals per meter). In drilling, the term refers to the pressure exerted by the drilling fluid in the wellbore. In a water drive field, the term refers to the pressure that may furnish the primary energy for production.

The maximum volume of natural gas that can be processed through an absorber at a specified absorption oil rate, temperature, and pressure without exceeding pressure drop or any other operating limitation.

In drilling, the entrance of formation fluids into the wellbore because hydrostatic pressure is less than formation pressure.

To screw a length of pipe into another length of pipe.

The normal pressure divided by true vertical depth.

The ratio between the pressure required to open the preventer and the well pressure under the rams.

A sealing component for a blowout preventer that closes the annular space between the pipe and the blowout preventer or wellhead.

The small amount of additional mud weight carried over that needed to balance formation pressure to overcome the pressure-reduction effects caused by swabbing when a trip out of the hole is made.

A device to provide running the tubing dry with a packer released by elevating tubing pressure, thereby opening the tubing to formation pressure.

The course of drilling fluid downward through the annulus and upward through the drill stem, in contrast to normal circulation in which the course is downward through the drill stem and upward through the annulus. Seldom used in open hole, but frequently used in workover operations. Also referred to as "circulating the short way," since returns from bottom can be obtained more quickly than in normal circulation.

A self-propelled floating offshore drilling unit that is a ship constructed to permit a well to be drilled from it. While not as stable as Semisubmersible, drill ships are capable of drilling exploratory wells in deep, remote waters. They may have a ship hull, a catamaran hull, or a trimaran hull. See floating offshore drilling rig.

The point at which a formation will crack from pressure in the wellbore.

Pipe in which the outside diameter of the joint is the same as the outside diameter of the tube. Pipe may also be internally flush-joint.

A Y-shaped chain used to spin up (tighten) one joint of drill pipe into another. One end of the chain is attached to the tongs, another end to the spinning cathead, and the third end left free. The free end is wrapped around the tool joint, and the cathead pulls the chain off the joint, causing the joint to spin rapidly and tighten up. After the free end of the chain is pulled off the joint, the tongs are secured in the spot vacated by the chain and continued pull on the chain (and thus on the tongs) by the cathead makes up the joint to final tightness.

The force exerted by a column of liquid expressed by the height of the liquid above the point at which the pressure is measured. Although "head" refers to distance or height, it is used to express pressure, since the force of the liquid column is directly proportional to its height. Also called head or hydrostatic head. Compare hydrostatic pressure.

An uncontrolled flow of gas, oil, or other well fluids into the atmosphere or into an underground formation. A blowout, or gusher, can occur when formation pressure exceeds the pressure applied to it by the column of drilling fluid.

2. a valve used to regulate automatically a uniform pressure on the inlet side of the valve.

A pin shaped like a carpenter's nail and placed in a pressure relief valve. When the pin shears, it opens the valve to relieve pressure inside a vessel.

A fluid moving as a unit in which all shear stress occurs at the pipe wall and hole wall. The stream thus assumes the shape of several telescopic layers of fluid with lowest velocities near the pipe and hole walls and the fastest in the middle.

An opening of a measured diameter that is used for measuring the flow of fluid through a pipe, the orifice must be of smaller diameter than the pipe diameter. It is drilled into an orifice plate held by an orifice fitting.

The pressure in a vessel or container as registered on a gauge attached to the container. This reading does not include the pressure of the atmosphere outside the container.

1. a scraping tool that is forced through a pipeline or flow line to clean out accumulations of wax, scale, and debris from the walls of the pipe. It travels with the flow of product in the line, cleaning the pipe walls by means of blades or brushes affixed to it. Also called a line scraper or a go-devil.

1. a valve used to regulate back-pressure on equipment or systems through which a fluid flows.

Pipe tongs that grip the pipe with a chisel-like insert in the jaw of the wrench.

A device that prevents leakage along a piston, rod, propeller shaft, or other moving part that passes through a hole in a cylinder or vessel. It consists of a box or chamber made by enlarging the hole and a gland containing compressed packing. On a well being artificially lifted by means of a sucker rod pump, the polished rod operates through a stuffing box, preventing escape of oil and diverting it into a side outlet to which is connected the flow line leading to the oil and gas separator or to the field storage tank. For a bottomhole pressure test, the wireline goes through a stuffing box and lubricator, allowing the gauge to be raised and lowered against well pressure. The lubricator provides a pressure-tight grease seal in the stuffing box.

A device placed or hung in the casing below the blowout preventer stack to form a pressure tight seal. Pressure is then applied to the blowout preventer stack to test it for leaks

Generically, a pressure gauge usually used in lines or manifolds. Many companies make pressure gauges. Cameron, now Cooper Oil Tools, makes many types of gauges.

Pressure of the annular fluid on the casing at the surface when a well is shut in

To pump drilling fluid into the wellbore while the pipe is being withdrawn to ensure that the wellbore remains full of fluid even though the pipe is withdrawn. Filling the hole lessens the danger of a kick or of caving of the well or the wellbore.

Gas pressure built up between the casing and tubing.

The pressure at which a formation will break down, or fracture.

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 well logging.

A variation of squeeze cementing for wells with two producing zones in which (1) the upper fluid sand is perforated; (2) tubing is run with a packer, and the packer is set between the two perforated intervals; (3) water is circulated between the two zones to remove as much mud as possible from the channel; (4) cement is pumped through the channel and circulated; (5) the packer is released and picked up above the upper perforation, a low squeeze pressure is applied, and the excess cement is circulated out. The process is applicable where there is communication behind the pipe between the two producing zones because of channeling of the primary cement or where there is essentially no cement in the annulus.

An entry of water, gas, oil, or other formation fluid into the wellbore during drilling. It occurs because the pressure exerted by the column of drilling fluid is not great enough to overcome the pressure exerted by the fluids in the formation drilled. If

See rise pipe.

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

Drill stem test

The cutting or boring element used for drilling. See bit.

The pressure at the bottom of a well.

The process of raising or lifting fluid from a well by injecting gas down the well through tubing or through the tubing-casing annulus. Injected gas aerates the fluid to make it exert less pressure than the formation does; consequently, the higher formation pressure forces the fluid out of the wellbore. Gas may be injected continuously or intermittently, depending on the producing characteristics of the well and the arrangement of the gas-lift equipment.

V: to reduce the size of the wellbore and drill ahead.

A valve that opens at a preset pressure to relieve excessive pressures within a vessel or line. Also called a relief valve, safety valve, or safety relief valve.

A floating offshore drilling unit that has pontoons and columns that when flooded cause the unit to submerge in the water to a predetermined depth. Living quarters, storage space, and so forth a reassembled on the deck. Semisubmersible rigs are either self-propelled or towed to a drilling site and either anchored or dynamically positioned over the site, or both. In shallow water, some semisubmersibles can be ballasted to rest on the seabed. Semisubmersibles are more stable than drill ships and ship-shaped barges and are used extensively to drill wildcat wells in rough waters such as the North Sea. Two types of semisubmersible rigs are the bottle-type semisubmersible and the column-stabilized semisubmersible. See floating offshore drilling rig.

An operation in which a specially blended liquid is pumped down a well and into a formation under pressure high enough to cause the formation to crack open, forming passages through which oil can flow into the wellbore. Sand grains, aluminum pellets, glass beads, or similar materials are carried in suspension into the fractures. When the pressure is released at the surface, the fractures partially close on the proppants, leaving channels for oil to flow through to the well. Compare explosive fracturing.

1. the process of raising the drill stem out of the wellbore when the well is shut in on a kick.

To lower the drill stem, tubing, casing, or sucker rods in to the wellbore.

The operation of hoisting the drill stem out of and returning it to the wellbore. See make a trip.

To bore a hole in the earth, usually to find and remove subsurface formation fluids such as oil and gas.

A record of information derived from examination of drilling fluid and drill bit cuttings. See mud logging.

Generally, the first string of casing in a well. It may be lowered into a hole drilled into the formations near the surface and cemented in place; it may be driven into the ground by a special pile driver (in such cases, it is sometimes called drive pipe); or it may be jetted into place in offshore locations. Its purpose is to prevent the soft formations near the surface from caving in and to conduct drilling mud from the bottom of the hole to the surface when drilling starts. Also called conductor pipe.

The process in which reservoir fluids are caused to flow out of the reservoir rock and into a wellbore by natural energy. Gas drives depend on the fact that, as the reservoir is produced, pressure is reduced, allowing the gas to expand and provide the driving energy. Water-drive reservoirs depend on water pressure to force the hydrocarbons out of the reservoir and into the wellbore.

A sub part of which is formed in the shape of a horseshoe and used to orient the drill stem downhole.

Generally, the first string of casing in a well. It may be lowered into a hole drilled into the formations near the surface and cemented in place; or it may be driven into the ground by a special pile drive (in such cases, it is sometimes called drive pipe); or it may be jetted into place in offshore locations. Its purpose is to prevent the soft formations near the surface from caving in and to conduct drilling mud from the bottom of the hole to the surface when drilling starts. Also called conductor pipe.

A spherical object used to pump down the drill string or tubing to trip, release, or otherwise operate certain hydraulic-type tools.

A bend in pipe, a ditch, or a well.

2. sometimes used to mean washover pipe.

The crew member who handles the upper end of the drill string as it is being hoisted out of or lowered into the hole. He is also responsible for the circulating machinery and the conditioning of the drilling fluid.

2. to recover bottomhole fluids, samples, mud, sand, or drill cuttings by lowering a cylindrical vessel called a bailer to the bottom of a well, filling it, and retrieving it.

The depth in the hole at which the drill stem, tubing, or casing is stuck.

Very small tubing or pipe.

2. a boot, or flume.

A valve or pipe through which bleeding is done.

A pipe through which flow is downward.

A length of pipe used to increase.

The flow of fluids within a pipe.

To run casing or pipe.

The joining of two length of pipe.

Movement of drilling fluid from mud pits, down drill stem, up annulus, and back to mud pits.

See lost circulation. lower kelly cock n: see drill stem safety valve

The operation of hoisting the drill stem from and returning it to the wellbore. v: shortened form of "make a trip."

See lost circulation. lower kelly cock n: see drill stem safety valve

The weight of the drill stem that is suspended from the hook.

Drill stem test tool; used for formation evaluation.

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

A pipe coupling threaded on the inside.

Two lengths or joints of pipe joined together.

A pipe through which liquid travels upward.

2. a device used to support a pipeline.

Pull on pipe over and beyond its weight in either air or fluid

To guide the end of a pipe into a coupling when making up a connection.

A person who tests pipe and casing for leaks

To measure and record length of pipe of tubing

A pipe or rod coupling with the threads on the inside.

Pressure at the top of a well when it is shut in.

The hoisting mechanism on a drilling rig. It is essentially a large winch that spools off or takes in the drilling line and thus raises or lowers the drill stem and bit.

The electrokinetic portion of the spontaneous potential electric-log curve that can be influenced significantly by the characteristics of the filtrate and mud cake or the drilling fluid that was used to drill the well.

Running pipe or tubing and landing it on a downhole tool.

The buckling of tubing in a large-diameter pipe or casing.

The lowering of pipe or tubing into the bore of a downhole tool.

A definite amount of oil, mud, acid, or other liquid in a tank or pipe.

2. pressure, volume, and temperature.

Pressure drop

See formation pressure

To loosen a tight joint as in line pipe or sucker rods.

The surface pipe through which oil travels from a well to processing equipment or to storage.

A very short piece of pipe having threads over its entire length.

A slip-type collar that is used to join plain-end pipe.

Relatively small-diameter pipe that is run into a well to serve as a conduit for the passage of oil and gas to the surface.

Material used on threads of pipe or tubing to lubricate and prevent leakage.

See extreme-pressure lubricant

Those parts of the drilling or workover rig that are designed to turn or rotate the drill stem and bit - swivel, kelly, kelly busing, master bushing, and rotary table.

Pertaining to packers and other tools left in the wellbore to be broken up later by the drill bit. Drillable equipment is made of cast iron, aluminum, plastic, or other soft, brittle material.

Abbreviation: shut-in casing pressure

2. the process of removing tubing from the well under pressure.

2. the process of putting tubing into a well under pressure.

Any law relating to the pressure, temperature, or volume of a gas.

An elastomer (seal) energized by pressure

A training procedure to determine that rig crews are completely familiar with correct operating practices to be followed in the use of blowout prevention equipment. A "dry run" of blowout preventative action.

1. a circular device with a frictional gripping arrangement used to suspend casing and tubing in a well.

N. a tool used to shape, form, or finish other tools or pieces of metal. For example, a threading die is used to cut threads on pipe.

A string of pipe used in workover of well-servicing operations; not typically considered as production tubing.

To lower pipe or tubing onto a downhole tool, transferring all or part of the hook load.

A short, threaded tubular coupling used for making connections between pipe joints and other tools.

1. in piping, a metal collar with internal threads used to join two sections of threaded pipe.

Preventers installed on top of the well or drill string as a precautionary measure while running wirelines. The preventer packing will close around the wireline.

A drilling mud, e.g., oil-base mud and invertemulsion mud, in which oil is the continuous phase. It is useful in drilling certain formation that may e difficult or costly to drill with water-base mud. Compare oil emulsion mud.

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)

2. any pumping procedure in which fluid is pumped into the well against pressure.

Abbreviation: choke-line friction pressure.

Flexible coupling used in high-pressure lines.

V: to drill wildcat wells.

2. a device within some hooks that acts as a shock absorber in eliminating the bouncing action of pipe as it is picked up.

2. gauge or measure pipe by means of a mandrel passed through it to ensure the passage of tools, pumps, and so on.

1. the ramp at the side of the drilling rig where pipe is laid to be lifted to the derrick floor by the catline or by an air hoist.

Wedge-shaped toothed pieces of metal that fit inside a bowl and are used to support tubing or other pipe.

A stand of pipe made up or three joints and handled as a unit. Compare double, fourable, and single.

To overcome pressure in a well by use of mud or water so that surface connections may be removed.

An unloader; provides a means to equalize tubing and annulus pressure.

A surface device used in pressure control for slickline.

A pressure-multiplier-type well servicing mobile pump.

A bottomhole assembly consisting of stabilizers and large-diameter drill collars arranged in a particular configuration to maintain drift angle and direction of a hole.

Position the correct number of feet or joints of pipe from the packer to the surface tree, or from the rig floor to the stack.

A system of connected lengths of pipe, usually buried in the earth or laid on the seafloor, that is used for transporting petroleum and natural gas.

A sub in a DST string in which pressure and temperature recorders are placed for formation evaluation.

(2) separating gas from that portion of associated and non-associated gas which liquefies at temperature and pressure conditions of the separator.

3. trying to pump out a gas influx before the expansion of gas reduces pressure allowing the well to kick.

The tendency of a metal bar or pipe to taper to a reduced diameter at some point when subjected to excessive longitudinal stress. See bottleneck.

A tool that goes inside pipe lost in a well to provide a firm grip and permit recovery of the fish. Sometimes used in place of a spear.

An injection well used for injecting fluids into an underground stratum to increase reservoir pressure.

A well through which fluids are injected into an underground stratum to increase reservoir pressure and to displace oil.

Used to describe packers with one slip system for supporting weight and pressure from above only.

3. a fractionation system that reduces the vapor pressure so that the resulting liquid is less volatile.

To pump a designated quantity of a substance (such as acid or cement) into a specific interval in the well. For example, 10 barrels of diesel oil may be spotted around an area in the hole in which drill collars are stuck against the wall of the hole in an effort to free the collars.

1. a tool placed on a drill collar near the bit that is used, depending on where it is placed, either to maintain a particular hole angle or to change the angle by controlling the location of the contact point between the hole and the collars. See packed-hole assembly.

The initial loss of mud solids by filtration, making formations easier to drill. See filtration loss.

A well into which gas in injected for the purpose of maintaining or supplementing pressure in an oil reservoir. More commonly called a gas injection well.