A heavy coupling element for drill pipe. It is made of special alloy steel and has coarse, tapered threads and seating shoulders designed to sustain the […]

An employee of a drilling contractor who is in charge of the entire drilling crew and the drilling rig. Also called a drilling foreman, rig manager, […]

Top drive systems primarily function like a power swivel, applying rotary torque to the drill pipe at the top of the drill string. Some early top […]

An adaptor that attaches to the top drive eliminating floor tongs and manual handling of casing using the power and rotation from the top drive. When […]

The turning force that is applied to a shaft or other rotary mechanism to cause it to rotate or tend to do so. Torque is measured […]

A hydraulic device connected between an engine and a mechanical load such as a compound. Torque converters are characterized by an ability to increase output torque […]

The maximum depth reached in a well.

A working shift for drilling crew or other oilfield workers. The most common tour is 8 hours; the three daily tours are called daylight, evening (or […]

The gear or chain arrangement by which power is transmitted from the prime mover to the drawworks, mud pump, or rotary table of a drilling rig.

Are related terms for expressing the same basic idea. The difference between input horsepower and output horsepower is transmission loss. It may be stated as so […]

A body of permeable oil-bearing rock surrounded or overlain by an impermeable barrier that prevents oil from escaping. The types of traps are structural, stratigraphic, hydrodynamic, […]

An arrangement of pulleys, or sheaves, through which drilling line is reeved and which moves up and down in the derrick or mast. See block.