An accessory employed above a packer, to permit annulus-to-tubing circulation or vice versa.

Abbreviation: 1,000 cubic feet of gas, commonly used to express the volume of gas produced, transmitted, or consumed in a given period.

A stratum of sand or porous sandstone from which natural gas is obtained.

To run and cement casing at a certain depth in the wellbore. Sometimes called set pipe.

The erratic, nonlinear flow of a fluid, caused by high velocity. Characterized by random eddying flow patterns superimposed on the general flow progressing in a given direction.

Abbr. American petroleum institute

The point in a well from which depth is measured. Alternatively, the depth reference is the point at which the depth is defined as being zero. it is typically the top of the kelly bushing or the level of the rig floor on the rig used to drill the well. The depth measured from that point [...]

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

A complex carbohydrate sometimes added to drilling fluids to reduce filtration loss.

A portable mast constructed of tubular members. A pole mast may be a single pole, usually one or two different sizes of pipe telescoped together to be moved or extended and locked to obtain maximum height above a well. Double-pole masts give added strength and stability. See mast.

The amount of the pore volume of a reservoir rock that is filled by water, oil, or gas and measured in routine core analysis.

To straighten and clean threads of any king.