Oil & Gas Glossary 1.0

A bottomhole choke run on wireline and landed in a nipple profile in the tubing string.

A choke in which the orifice size must be changed to change the rate of flow through the choke.

A set of controls, usually placed on the rig floor, that is manipulated to control the amount of drilling fluid being circulated through the choke manifold. This procedure is necessary when a kick is being circulated out of a well. See choke manifold.

An arrangement of piping and special valves, called chokes. In drilling, mud is circulated through a choke manifold when the blowout preventers are closed. In well testing, a choke manifold attached to the wellhead allows flow and pressure control for test components downstream.

An extension of a retrievable tool, i.e., a retrievable bridge plug, used to set and release the tool.

Specialized tools used to run equipment in a well, such as a wireline running tool for installing retrievable gas lift valves. Various tubing-type running tools are also used.

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

A device placed in a choke line that regulates the flow through the choke. Flow depends on the size of the opening in the bean; the larger the opening, the greater the flow.

The valve on the choke and flow line that is nearest to the preventer assembly. Its purpose is to stop the flow through the choke and flow line.

An extension from the blowout preventer assembly used to direct control the flow of well fluids from the annulus to the choke.

A pipe attached to the blowout preventer stack out of which kick fluids and mud can be pumped to the choke manifold when a blowout preventer is closed in on a kick.

2. in wireline, trying to pull out of the well faster than the wireline tools are being blown upwards by unexpected pressure.

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

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

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.

A small-diameter metal line used in wireline operations. Also called slick line. Compare conductor line.

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

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

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.

A tool that goes downhole and is not retrievable.

A small-diameter conductive line used in electric wireline operations, such as electric well logging and perforating, in which the transmission of electrical current is required. Compare wireline.

A trademark for a retrievable squeeze tool.

A pulley that is normally attached to the wellhead at a convenient place for the wireline to pass through as it comes from the stuffing box sheave before being spooled onto the wireline reel. The hay pulley prevents any lateral force from being exerted on the lubricator and the wellhead.

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 tes5t 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 tip in the hole, so they are very useful in formation testing.

A generic term to describe a retrievable service packer.

A tube placed around the retrieving neck of a retrievable bridge plug to "catch" debris.

A generic term used to describe a retrievable service squeeze tool; used in remedial cementing.

A portable mast that an be erected as a unit, usually by a tackle that hoists the wireline or by hydraulic pistons. The upper section of a telescoping derrick is generally nested (telescoped) inside the lower section of the structure and raised to full height either by the wireline or by a hydraulic system.

A storm choke

A tubing safety valve.

Abbreviation: choke-line friction pressure.

A retrievable tool used to suspend drilling temporarily during a storm offshore.

A retrievable or drillable packer in which sufficient pipe weight is not available to set the tool in compression.

A choke, used to regulate flow of fluid from a well. Different sizes of beans are used for different producing rates.

A retrievable receptacle anchored into the top of a production packer to land a tubing seal assembly

A device inserted in a flow line to regulate the rate of flow.

In well-control operations, closing the BOP's with the choke and HCR, or fail-safe, valves open. Compare hard shut-in.

A tool used to open or close a downhole valve; a tool used to set or release a downhole tool, such as a retrievable bridge plug.

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.

See back-pressure

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

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

A device to connect the wireline to the tool string.

A fitting placed in the blowout preventer stack to provide space between preventers for facilitating stripping operations, to permit attachment of choke and kill lines, and for localizing possible erosion by fluid flow to the spool instead of to the more expensive pieces of equipment.

2. to force a wireline tool or tubing down the hole by using a reciprocating motion.

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

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

To fire a wireline-operated downhole tool from inside the service truck.

N. 1. a piece of cloth, rope or nylon strand used to mark the wireline when swabbing or bailing.

A ported, extended production tub used as an alternative path for wireline measuring devices.

The wireline attached to ground anchors to provide lateral support for a mast or derrick.

Abbreviation: a generic term for pressure setting assembly; a tool that is used to set permanent tools on electric wireline, through explosive force.

2. in swabbing or bailing, to attach a piece of cloth to the wireline to enable the operator to estimate the position of the swab or bailer in the well.

A well is considered "stabilized" when, in the case of a flowing well, the rate of production through a given size of choke remains constant, or, in the case of pumping well, when the fluid column within the well remains constant in height.

A method of killing a well in which the mud level in the pits is held constant while the choke size is reduced and the pump speed slowed. It is not effective, and therefore, is not recommended, because casing pressure increases to the point at which the formation fractures or casing ruptures, and control of the well is lost.

A wireline attached to a mast, derrick, or offshore platform to stabilize it. See wind guy line.

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

A valve in the bottom of a retainer. See wireline.

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.

A device used to measure the depth of a well or the depth at a specific point in a well (such as to the top of a liner or to a fish) by counting the turns of a calibrated wheel rolling on a wireline as it is lowered into or pulled out of the well.

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.

A poppet spring-loaded subsurface valve run in on wireline, landed in a profile, to shut the well if injection ceases.

Descriptive of any tool or device that can be pumped down a wellbore. Pump-down tools are not lowered into the well on wireline; instead, they are pumped down the well with the drilling fluid.

A cylindrical or spherical device that is affixed to the end of a wireline just above the hook to keep the line straight and to provide weight. v: to soak metal pieces in a chemical solution to remove dirt and scale from the metal's surface.

A wireline used on drilling rigs and well servicing rigs to operate a swab or bailer, to retrieve cores or to run logging devices. It is usually 9/16 of an inch (15 millimeters) in diameter and several thousand feet or meters long

A piece of downhole equipment, consisting of a sealing device, a holding or setting device, and an inside passage for fluids, used to block the flow of fluids through the annular space between the tubing and the wall of the wellbore by sealing off the space between them. It is usually made up in the tubing string some distance above the producing zone. A packing element expands to prevent fluid flow except through the inside bore of the packer and into the tubing. Packers are classified according to configuration, use, and method of setting and whether or not they are retrievable (that is, whether they can be removed when necessary, or whether they must be milled or drilled out and thus destroyed).

A heavy weight or bar placed on or near a lightweight wireline tool. The bar provides weight so that the tool will lower properly into the well.

A wireline pressure setting tool for setting permanent downhole tools.

A special device placed in a string of tubing that can be operated by a wireline tool to open or close orifices to permit circulation between the tubing and the annulus. It may also be used to open or shut off production from various intervals in a well. Also called circulation sleeve.

V: 1. to operate a swab on a wireline to bring well fluids to the surface when the w4ell does not flow naturally. Swabbing is a temporary operation to determine whether the well can be made to flow. If the well does not flow after being swabbed, a pump is installed a a permanent lifting device to bring the oil to the surface.

A workover performed with a continuous steel tube, normally 3/4 inch to 1 inch outside diameter, which is run into the well in one piece inside the normal tubing. Lengths of the tubing up to 16,000 feet are stored on the surface on a reel in a manner similar to that used for wireline. The unit is rigged up over the wellhead. The tubing is injected through a control head that seals off the tubing and makes a pressure-tight connection. A unique feature of the unit is that it allows continuous circulation while it is being lowered into the hole.

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 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.

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.