collapsing of the walls of the wellbore. Also called sloughing.

Related Terms

• Pig

1. a scraping tool that is forced through a pipeline or flow line to clean out accumulations of wax, scale, and debris from the walls of the pipe. It travels with the flow of product in the line, cleaning the pipe walls by means of blades or brushes affixed to it. Also called a line...

• Cave-in

the collapse of the walls of the wellbore....

• Diatomaceous Earth

an earthy deposit made up of the siliceous cell walls of one-celled marine algae called diatoms. It is used as an admixture for cement to produce a low-density slurry....

• Cement

a powder, consisting of alumina, silica, lime, and other substances that hardens when mixed with water. Extensively used in the oil industry to bond casing to the walls of the wellbore....

• Blowout

1. An uncontrolled flow of gas, oil, or other well fluids into the atmosphere or into an underground formation. A blowout, or gusher, can occur when formation pressure exceeds the pressure applied to it by the column of drilling fluid. 2. An uncontrolled flow of reservoir fluids into the wellbore, and sometimes catastrophically to the surface....