Oil & Gas Glossary 1.0

See casing hanger, tubing hanger

A hanger used to lock instruments into seating nipple (pressure/temperature bombs, etc.).

A temporary plug set of a PSA, landed in a production packer to convert it to a bridge plug.

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

Any object or device that blocks a hole or passageway (such as a cement plug in a borehole).

A rubber plug used in primary cementing operations to displace cement slurry from the casing into the borehole annulus.

A downhole tool, composed primarily of slips, a plug mandrel, and a rubber sealing element, that is run and set in casing to isolate a lower zone while an upper section is being tested or cemented.

A secondary-cementing operation in which a plug of cement is positioned at a specific point in the well and allowed to set.

See gunk plug

2. a device used to support a pipeline.

A device used to hang sucker rods on the mast or in the derrick

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

A device set in tubing, particular collars, to facilities the landing of pressure bombs (recorders).

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

Any cementing operation after the primary cementing operation. Secondary cementing includes a plug-back job, in which a plug of cement is positioned at a specific point in the well and allowed to set. Wells are plugged to shut off bottom water or to reduce the depth of the well for other reasons.

A circular device with a frictional gripping arrangement of slips and packing rings used to suspend casing from a casinghead in a well

An arrangement of slips and packing rings used to suspend tubing from a tubing head.

A small attachment on the rod-transfer equipment that picks up the rods after they are unscrewed from the string and then transfers them to the rod hanger, or reverses the procedure when going into the hole. See rod-transfer equipment.

Abbreviation: plug and abandon

See cementing head.

To shut off lower formation in a well bore.

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

1. to cease efforts to produce oil or gas from a well, and to plug a depleted formation and salvage all material and equipment.

A threaded nipple with a rounded, closed end used to stop up a hole or close off the end of a line.

A tool used to mill over permanent bridge plugs/cement retainers while retrieving the milled-out debris

A bull plug or blind flange at the end of a tee to prevent erosion at a point where change in flow direction occurs.

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

A portion of cement placed at some point in the wellbore to seal it. See cementing.

A small plug that is run through a flow line by pressure to clean the line or test for obstructions (see pig).

To place cement plugs into a dry hole and abandon it.

A plug in the flow line at the well head which has a small hole drilled through it through which oil flows, and which keeps a well from flowing at too high a rate.

To close off, such as with a blank flange or bull plug.

To plug open perforations by using ball sealers.

A reservoir formation in which fluid or plastic masses of rock material originated at unknown depths and pierced or lifted the overlying sedimentary strata.

A slurry in crude or diesel oil containing any of the following materials or combinations: bentonite, cement, attapulgite, and guar gum (never with cement). Used primarily in combating lost circulation.

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

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

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

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.

See valve

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.

A device used to control the rate of flow in a line to open or shut off a line completely, or to serve as an automatic or semiautomatic safety device. Those used extensively include the check valve, gate valve, globe valve, needle valve, plug valve, and pressure relief valve.

A globe valve that contains a sharp, pointed, needle-like plug that is driven into and out of a cone-shaped seat to control accurately a relatively small rate of fluid flow. In a fuel injector, the fuel pressure forces the needle valve off its seat to allow injection.

A dome that is caused by an intrusion of rock salt into overlying sediments. A piercement salt dome is one that has been pushed up so that it penetrates the overlying sediments, leaving them truncated. The formations above the salt plug are usually arched so that they dip in all directions away from the center of the dome, thus frequently forming traps for petroleum accumulations.

The state in fluid dynamics of a fluid in motion is determined by the type of fluid (e.g., Newtonian, plastic, pseudoplastic, dilatant); the properties of the fluid such as viscosity and density; the geometry of the system; and the velocity. Thus, under a given set of conditions and fluid properties, the fluid flow can be described as plug flow, laminar (called also Newtonian, streamline, parallel, or viscous) flow, or turbulent flow.

A squeeze cementing method in which a packer is set to form a seal between the working string (the pipe down which cement is pumped) and the casing. Another packer or a cement plug is set below the point to be squeeze-cemented. By setting packers, the squeeze point is isolated from the rest of the well. See packer, squeeze cementing.