A device used in fishing for drill pipe.

If the upper end of the lost pipe is leaning against the side of the wellbore, the wall hook centers it in the hole so that it may be recovered with an overshot, which is run on the fishing string and attached to the wall hook.

A hole drilled in the earth for purpose of (1) finding or producing crude oil or natural gas; or (2) providing services related to the production of crude oil or natural gas.

A substance or composition that, when added to a liquid, increases the spreading of the liquid on a surface or the penetration of the liquid into a material.

A drilling mud in which the continuous phase is water.

In water-gas muds, any additives are dispersed in the water.

Compare oil-base mud.

Water put into an empty string of pipe in a wellbore to prevent the pipe from being crushed by pressure in the annulus.

1.

The activities and methods of preparing a well for the production of oil and gas or for other purposes, such as injection; the method by which one or more flow paths for hydrocarbons are established between the reservoir and the surface.

2.

The system of tubulars, packers, and other tools installed beneath the wellhead in the production casing; that is, the tool assembly that provides the hydrocarbon flow path or paths.

The amount by which drilling fluid density is reduced by entrained formation fluids or air.

A borehole; the hole drilled by the bit.

A wellbore may have casing in it or it may be open (uncased); or part of it may be cased, and part of it may be open.

Also called a borehole or hole.

A member of a well-servicing crew.

To increase the weight or density of drilling fluid by adding weighting material.

An instrument near the driller’s position on a drilling rig that shows both the weight of the drill stem that is hanging from the hook (hook load)

Pertaining to the time when drilling or completion operations are suspended so that the cement in a well can harden sufficiently.