Steel casing hammered or pushed into place where soil strata are high in gravel and cobble content or where formation strength is low and the bore would be unstable.

The outer casing of a well. The purpose of this casing is to prevent contaminants from surface waters or shallow groundwaters from entering a well.

Prevents collapse of the loose soil near the surface of a borehole.

Generally, the first string of casing in a well. It may be lowered into a hole drilled into the formations near the surface and cemented in place; it may be driven into the ground by a special pile driver. Its purpose is to prevent the soft formations near the surface from caving in and to conduct drilling mud from the bottom of the hole to the sur [..]