The derrickman’s working platform. As pipe or tubing is run into or out of the hole, the derrickman must handle the top end of the pipe, […]

See graveyard tour.

The crew member on a rotary drilling rig, usually the most experienced rotary helper, who is responsible for the care and operation of drilling engines. Compare […]

A shallow cased hole close to the rotary table through the derrick floor in which a joint of drill string can be suspended to facilitate connecting […]

The procedure of adding a length of drill pipe or tubing to the active string. The length to be added is placed in the mousehole, made […]

The liquid circulated through the wellbore during rotary drilling and workover operations. In addition to its function of bringing cuttings to the surface, drilling mud cools […]

Examination and testing of drilling mud to determine its physical and chemical properties.

An instrument consisting of a cup and a graduated arm with a sliding weight and resting on a fulcrum, used to measure weight of the mud.

The sheath of mud solids that forms on the wall of the hole when liquid from mud filters into the formation. Also called filter cake or […]

The process of pumping mud downward to the bit and back up to the surface in a drilling or workover operation. See normal circulation, reverse circulation.

The treatment and control of drilling mud to ensure that it has the correct properties. Conditioning may include the use of additives, the removal of sand […]

An employee of a drilling fluid supply company whose duty it is to test and maintain the drilling mud properties that are specified by the operator.