A measure of the ability of a single fluid to flow through a rock when another fluid is also present in the pore spaces. Compare absolute […]

The percentage of the bulk volume of a rock sample that is composed of interconnected pore spaces that allow the passage of fluid through the sample. […]

A record of certain electrical characteristics (such as resistivity and conductivity) of formations traversed by the borehole. It is made to identify the formations, determine the […]

A device mounted on the end of the drawworks shaft of a drilling rig. The electrodynamic brake (sometimes called a magnetic brake) serves as an auxiliary […]

An internal combustion engine can, temporarily, develop at any speed a maximum usable horsepower; also, can temporarily, run at much higher speeds than economically feasible with […]

The shift of duty on a drilling rig that starts in the afternoon and runs through the evening. Sometimes called afternoon tour. Compare daylight tour, graveyard […]

A well drilled to permit more effective extraction of oil from a reservoir. Sometimes called a development well.

A well drilled either in search of an as yet undiscovered pool of oil or gas (a wildcat well) or to extend greatly the limits of […]

When explosives are used to fracture a formation. At the moment of detonation, the explosion furnishes a source of high-pressure gas to force fluid into the […]