An arrangement of piping and special valves, called chokes. In drilling, mud is circulated through a choke manifold when the blowout preventers are closed; a choke […]

A valve that permits flow in one direction only.

To pass from one point throughout a system and back to the starting point. For example, drilling fluid is circulated out of the suction pit, down […]

A fluid consisting of water, oil, or other liquid and containing clay, weighting materials, and/or chemicals, which is circulated through the drill pipe and wellbore during […]

The movement of drilling fluid out of the mud pits, down the drill stem, up the annulus, and back to the mud pits.

Sodium carboxymethylcellulose. A nonfermenting cellulose product used in drilling fluids to combat contamination from anhydrite (gyp) and lower the water loss from the drilling fluid to […]

An automated system of arms on a column that can be a fixed rotating (radial pattern) machine or a traveling and rotating machine. Usually consists of […]

A casing string with joints of various collapse resistance, internal yield strength and tensile strength, designed for various depths in a specific well to best withstand […]

See Company representative.

An employee of an operating company whose job is to represent the company’s interest at the drilling location.

1) a mechanism used to transmit power from the engines to the pump, the drawworks, and other machinery on a drilling rig. It is composed of […]

1) a short string of large-diam casing used to keep the wellbore open and to provide a means of conveying the up-flowing drilling fluid from the […]