Oil & Gas Glossary 1.0

See cementing head.

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.

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

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

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 container in which various chemicals are mixed prior to addition to drilling fluid.

2. the measured volume of water that is present in a container and that is not in suspension in the contained liquid at observed temperature.

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

A long, cylindrical container fitted with a valve at its lower end, used to remove water, sand, mud, drilling cuttings, or oil from a well in cable-tool drilling.

Container or vessel enclosing an arrangement of tubes and a firebox in which an emulsion is heated before further treating, or in which natural gas is heated in the field to prevent the formation of hydrates.

A phenomenon in which a pressure concession occurs by suddenly stopping the flow of liquids in a closed container. Also called water hammer.

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

The process by which a single quantity of crude oil emulsion is broken into oil and water. The emulsion is gathered and stored in a tank or container prior to treating.

Abbreviation: plug and abandon

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

To shut off lower formation in a well bore.

A relatively small container of high explosive that is loaded into a perforating gun. On detonation, the charge releases a small, high-velocity stream of particles (a jet) that penetrates the casing, cement, and formation. See perforating gun.

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

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

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 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 plug open perforations by using ball sealers.

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

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.

A compressible fluid that fills any container in which it is confined. Technically, a gas will not condense when it is compressed and cooled, because a gas can exist only above the critical temperature for its particular composition. Below the critical temperature, this form of matter is known as a vapor, because liquid can exist and condensation can occur. Sometimes the terms "gas" and"vapor" are used interchangeably. The latter, however, should be used for those streams in which condensation can occur and that originate form, or are in equilibrium with, a liquid phase.

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 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

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.