The cable attached to a bailer, passed over a sheave at the top of the derrick, and spooled on a reel.

Ballooning is flowback when pumps are off; caused by seepage losses when drilling or circulating.

Any one of many types of flat-decked, shallow draft vessels, usually towed by a boat. A complete drilling rig may be assembled on a drilling barge, […]

Barium sulfate, BaSO4; a mineral frequently used to increase the weight or density of drilling mud. Its relative density is 4.2 (i.e., it is 4.2 times […]

A chemical compound of barium, sulfur, and oxygen (BaSO4), which may form a tenacious scale that is very difficult to remove. Also called barite.

1) A measure of volume for petroleum products in the United States. One barrel is the equivalent of 42 U.S. gallons or 0.15899 cubic m (9702 […]

A barrier is defined as “a component or practice that contributes to the total system reliability by preventing formation fluid or gas flow” (API RP 96) […]

A fishing accessory run above a bit or a mill to recover small, non-drillable pieces of metal or junk in a well.

A specific layer of earth or rock that presents a contrast to other layers of different material lying above, below, or adjacent to it.

A short piece of pipe, expanded, or belled, at the top to guide tools into the hole. Usually has side connections for the fill-up and mud […]

A flexible band or cord connecting and wrapping around each of two or more pulleys to transmit power or impart motion.

A finely powdered gray material used in preparing drilling mud. Usually referred to on the rig as “gel”.