Casing is large diameter pipe that is assembled and inserted into a recently drilled section of a borehole and typically held into place with cement. Casing used to Isolates different zones, that may have different pressures or fluids - known as zonal isolation, in the drilled formations from one another, seals off high pressure zones from the surface, avoiding potential for a blowout prevents fluid loss into or contamination of production zones, provides a smooth internal bore for installing production equipment.

Casing is large diameter pipe that is assembled and inserted into a recently drilled section of a borehole and typically held into place with cement. Casing used to Isolates different zones, that may have different pressures or fluids - known as zonal isolation, in the drilled formations from one another, seals off high pressure zones from the surface, avoiding potential for a blowout prevents fluid loss into or contamination of production zones, provides a smooth internal bore for installing production equipment.