Casing
A casing is a steel pipe that is run in the well after drilling the hole to a certain depth. The casing is run to prevent the collapse of the drilling hole. In most cases, the casing is cemented to provide effective isolation to avoid communication between the zones behind the casing and the new formations to be drilled below the casing pipe in the next hole section. Various sizes of casing pipes are used in the industry. The grades and connections also vary depending on the application, design loads, and availability.