Glossary

1. joule. 2. productivity index, often used in engineering reports during well testing; also abbreviated PI.

the configuration of pipe when it enters the water from an inclined ramp on the stern of a lay barge instead of from a stinger. The J curve eliminates overbend, which can stress the pipe.

a chaser used to snag wire or chain mooring sections; usually hung over the stern roller on an anchor-handling vessel.

in laying pipe offshore from a pipe laying vessel, a system in which joints of pipe are welded in a vertical orientation to eliminate the need for a stinger. J-laying allows the pipe to be laid in deeper waters; also, a greater selection of vessels can be used. It is a slower process than the conventional S-lay method because of the pipe’s vertical welding position. Compare S-lay. See stinger.

a chaser that can only be pulled in one direction down a section of chain. In the other direction, it will lock.

a type of mechanism in a packer or a tool in which tubing rotation moves the tool’s mandrel through a series of motions, similar to a letter J, to set and release the tool.

Joule-Thomson valve. A detector cooling device in which a gas under high pressure escapes through an expansion valve in the tank; as the escaped gas liquefies, it cools the site of the sensor.

a sleeve receptacle that has a fitted male element and pins that fit into milled J-shaped slots of the sleeve. The short sides of the J-slots provide a shoulder for supporting weight on the pins of the male element. When the male element is lowered and turned relative to the sleeve, the pins slide in the slot toward the long side of the J, which is open-ended. The pins may thus be raised out, releasing weight that may be supported by the sleeve. The releasing procedure is called “unjaying the tool.”

a method for joining a pipeline to a subsea riser on a platform. In the J-tube method, the pipe is lifted off the ocean floor when it reaches the platform and is then fed up to the surface through a guide tube. During this process, the pipe assumes a J configuration. Compare reverse J-tube method.

1. an oilwell pumping unit that is powered by an internal-combustion engine, electric motor, or rod line from a central power source. The walking beam of the pumping jack provides reciprocating motion to the pump rods of the well. See walking beam. 2. a device that is manually operated to turn an engine over for starting. v: to raise or lift.

a device used to support the end of a length of pipe while another length is being screwed onto the pipe. Sometimes referred to as a stabbing jack.

1. a tubular piece of steel in a tubing liner-type of sucker rod pump, inside of which is placed an accurately bored and honed liner. In this type of sucker rod pump, the pump plunger moves up and down within the liner and the liner is inside the jacket. 2. the support structure of a steel offshore production platform; it is fixed to the seabed by piling, and the superstructure is mounted on it.

water that fills, or is circulated through, a housing that partially or wholly surrounds a vessel or machine to remove, add, or distribute heat and thereby to control the temperature within the vessel or machine.

1. a rock drill that is pneumatically powered and usually held by the operator. 2. an air hammer.

a structural steel, open-sided tower raised vertically by special lifting tackle attached to the traveling block. See mast. Compare standard derrick.

a drilling rig that has a jackknife mast instead of a standard derrick.

a short shaft that is usually set between two machines to provide increased or decreased flexibility and speed; term applied to an intermediate shaft.

a jackup drilling rig.

a mobile bottom-supported offshore drilling structure with columnar or open-truss legs that support the deck and hull. When positioned over the drilling site, the bottoms of the legs penetrate the seafloor. A jackup rig is towed or propelled to a location with its legs up. Once the legs are firmly positioned on the bottom, the deck and hull height are adjusted and leveled. Also called self-elevating drilling unit.

a percussion tool operated manually or hydraulically to deliver a heavy downward blow to fish stuck in the borehole. v: to apply a heavy blow to the drill stem by use of a jar or bumper sub.

a hydraulic tool used in conjunction with a jar and made up on the fishing string above the jar to increase the power of the jarring force.

see jar accelerator.

see tong jaw.

a positive-type clutch in which one or more jaws mesh in the opposing clutch sections.

the act of getting ready to use a J-slot packer or tool.

JEDEC Solid State Technology Association.

originally known as the Joint Electron Device Engineering Council (JEDEC), this association is the semiconductor engineering standardization body of the Electronic Industries Alliance (EIA), a trade association that represents all areas of the electronics industry. JEDEC was originally created in 1960 as a joint activity between EIA and the National Electrical Manufacturing Association (NEMA), to cover the standardization of discrete semiconductor devices and later expanded in 1970 to include integrated circuits. In spite of the name change, the association is usually abbreviated as JEDEC. Address: 2500 Wilson Blvd., Arlington, VA 22201; 703-907-7534; www.jedec.org.

see holiday detector.

a wire rope, one end of which is connected to the end of the breakout tongs and the other end of which is attached to the breakout cathead. When the driller activates the cathead, the cathead pulls on the jerk line with great force to apply torque to break out a tool joint (or to tighten a drill collar connection).

1. a hydraulic device operated by a centrifugal pump used to clean the mud pits, or tanks, and to mix mud components. 2. in a perforating gun using shaped charges, a highly penetrating, fast-moving stream of exploded particles that forms a hole in the casing, cement, and formation.

a drilling bit having replaceable noz­zles through which the drilling fluid is directed in a high-velocity stream to the bottom of the hole to improve the efficiency of the bit. See bit.

a fishing tool that fires a shaped charge downhole to break up junk so that it can be retrieved. It is run into the hole on drill pipe and collars.

a device employing a venturi nozzle through which a high-pressure stream creates a lower pressure or a vacuum into which the gas to be compressed flows. The gas is discharged from the nozzle with the expanded high-pressure medium.

a procedure for severing pipe stuck in a well by detonating special shaped-charge explosives similar to those used in jet perforating. The explosive is lowered into the pipe to the desired depth and detonated. The force of the explosion makes radiating horizontal cuts around the pipe, and the severed portion of the pipe is retrieved.

a fishing tool that uses shaped charges to sever casing, tubing, or drill pipe stuck in the hole. See jet cutoff. Compare chemical cutter.

a special jet bit that has a very large nozzle used to deflect a hole from the vertical. The large nozzle erodes one side of the hole so that the hole is deflected off vertical. A jet deflection bit is especially effective in soft formations.

an assembly, including a carrier and shaped charges, that is used in jet perforating.

a device to hold or feed drilling-mud additives. See mud-mixing devices.

a cement mixing system that combines dry cement with a jet of water. The turbulence from the water thoroughly mixes the cement slurry.

to use a jet for cleaning out mud tanks, cellar, and other areas.

a pump that operates by means of a jet of steam, water, or other fluid that imparts motion and subsequent pressure to a fluid medium.

a special pipe installed near the bottom of a mud tank that turns upward from the tank’s bottom and is inserted into the end of a larger pipe. When mud is pumped through the small pipe, the pressure lifts mud out of the tank through the larger pipe. This lifting effect is called a siphon effect.

in pipeline construction offshore, a pipe-straddling device fitted with nozzles on either side that is lowered by a bury barge. As water is pumped at high pressure through the nozzles, spoil from beneath the pipe is removed and pumped to one side of the trench. The line then sags naturally into position in the trench.

a relatively narrow band of winds in the upper troposphere, with speeds as high as 300 knots and traveling from west to east.

a tool used in the drill string when drilling with air or gas. A short length of pipe—a sub—is made up in the drill string to minimize surging. Surging occurs when air or gas in the liquid drilling fluid comes out of the liquid in large slugs, usually near the surface where pressure is low. A jet bit nozzle is screwed into a housing on the sub. A jet is selected that allows about 20 percent of the drilling fluid and gas to go into the annulus when drilling at equilibrium.

circulating a lower-density fluid to underbalance the well’s formation pressure to initiate flow.

to create holes through the casing with a shaped charge of high explosives instead of a gun that fires projectiles. The loaded charges are lowered into the hole to the desired depth. Once detonated, the charges emit short, penetrating jets of high-velocity gases that make holes in the casing and cement for some distance into the formation. Formation fluids then flow into the wellbore through these perforations. See bullet perforator, gun-perforate.

see jet-perforate.

see reverse-circulation junk basket.

the process of periodically removing a portion or all of the water, mud, and/or solids from the pits, usually by means of pumping through a jet nozzle arrangement.

junction-type field-effect transistor.

the projecting arm of a crane.

the term given to the exercise of identifying risks to health and safety in the workplace, and documenting the control measures taken to manage those risks.

a wholesaler who buys gasoline for resale to retailers.

1. in drilling, a single length (from 16 feet to 45 feet, or 5 metres to 14.5 metres, depending on its range length) of drill pipe, drill collar, casing, or tubing that has threaded connections at both ends. Several joints screwed together constitute a stand of pipe. 2. in pipelining, a single length (usually 40 feet—12 metres) of pipe. 3. in geology, a crack or fissure produced in a rock by internal stresses. 4. in sucker rod pumping, a single length of sucker rod that has threaded connections at both ends.

a now defunct consortium of manufacturers that devised standards mostly for computer memory modules. Replaced in 1998 by the JEDEC Solid State Technology Association.

a gauge for determining whether the connections of drill collars and tool joints match.

the shipment of a tender of oil through the facilities of one or more pipeline companies.

a length of drill pipe or casing. Both come in various lengths. See range length.

a contract by which two or more co-owners of the operating rights in a tract of land join to share the costs of exploration and possible development. Compare farmout.

the amount of hanging weight that can be placed on a connection without failure.

a rate sheet, issued jointly by two or more companies, setting forth charges for moving oil over the facilities of each.

two or more persons who are granted lands or tenements to hold in fee simple, fee tail for life, for years, or at will, whose joint title is created by one and the same deed or will. The survivor receives the whole on the death of the other.

a business undertaking, usually of more limited scope and length than a partnership, in which control, profits, losses, and liability are all shared.

the net surface tension of salt solutions first decreases with an increase of concentration, passes through a minimum, and then increases as the concentration is raised.

the unit used to measure heat, work, and energy in the metric system. It is the amount of energy required to move an object of 1 kilogram mass to a height of 1 metre. Also called a newton-metre.

the change in gas temperature that occurs when the gas is expanded adiabatically from a higher pressure to a lower pressure. The effect for most gases, except hydrogen and helium, is a cooling of the gas.

see J-T valve.

a law that states that the number of units of heat that develop in a circuit is proportional to the circuit’s resistance, to the square of the strength of the current, and to the time that the current lasts.

the part of a rotating shaft that turns in a bearing.

the angle formed by lines perpendicular to the axis of the journal and the axis of the bit. Also called pin angle.

a machine part in which a rotating shaft (a journal) revolves or slides. Also called a plain bearing. Compare ball bearing, roller bearing.

job safety analysis.

an inexpensive and widely used pressure-control head for normal workover operations. It holds well pressure at the surface while allowing tubing to be stripped into or out of the well. It also allows the work string to be rotated if necessary.

see judicial transfer.

transfer by the court of an interest or of interests in real property. When ownership of land is concerned, a judicial transfer usually involves the appointment of a receiver by the court. The receiver can then act, for example, to execute an oil and gas lease on the property. The citation may arise when the landowner is missing or unknown, after foreclosures, or after tax sales. Also called judicial determination.

see geophone.

(slang) the member of a seismograph crew who places the geophones.

a flare for burning waste gas when the volume of gas is very small or when no market is readily available.

tank cars having capacities of 30,000 gallons (114 cubic metres) or more. Standard tank cars have a capacity of 10,000 to 11,000 gallons (38 to 42 cubic metres).

in solid-state electronics, a region of transition between two semiconducting regions in a semiconducting device—for example, the region where the p and n materials come into contact.

a housing (a box) that provides a place for electrical, hydraulic, or pneumatic connections to be made from one part of the system to another. For example, a junction box on an accumulator provides a point for connecting (interfacing) the remote electrical panels, as well as the accumulator unit’s pod select valve, pilot valves, and various system pressures.

a transistor in which emitter and collector barriers are formed between the semiconductor regions of opposite conductivity (the region where the p and n materials come into contact). Also called a junction-type field-effect transistor (JFET).

see junction transistor.

a one-piece orifice fitting without flanges.

metal debris lost in a hole. Junk may be a lost bit, pieces of a bit, milled pieces of pipe, wrenches, or any relatively small object that impedes drilling or completion and must be fished out of the hole. v: to abandon (as a nonproductive well).

a device made up on the bottom of the drill stem or on wireline to catch pieces of junk from the bottom of the hole. Circulating the mud or reeling in the wireline forces the junk into a barrel in the tool, where it is caught and held. When the basket is brought back to the surface, the junk is removed. Also called a junk sub or junk catcher.

see boot sub.

a quantity of cement that is left over after an adequate amount of cement has been pumped into a well during a cement job.

a mill used to grind up junk in the hole. See mill.

a scraper device run below retainers or packers to clean away debris from casing ID.

a special tool made up on the bottom of the drill stem to pick up junk from the bottom of the hole. Most junk retrievers are designed with ports that allow drilling fluid to exit the tool a short distance off the bottom. This flow of fluid creates an area of low pressure inside the tool so that the junk is lifted and caught in the retriever by the higher pressure outside the tool. See junk, junk basket.

an explosive charge detonated in the borehole to break up large pieces of junk in order to facilitate the junk’s removal from the hole.

a groove in the side of a diamond or PDC bit that creates an area of low velocity where relatively small pieces of junk will be lifted and then sent up the hole in the drilling fluid.

a device made up in the drill stem to collect pieces of junk ground away during milling that may damage the bit or interfere with its operation. See boot sub.