Casing Definition / Meaning

Casing is a large-diameter pipe that is run into a wellbore and cemented in place to provide structural integrity, isolate formations, and enable safe and efficient hydrocarbon production. It serves as the permanent lining of the well, preventing the hole from caving in, protecting freshwater aquifers from contamination, and containing wellbore pressures. In production and operations, casing strings are designed to withstand the harsh downhole environment, including high pressures, temperatures, corrosive fluids, and mechanical loads.

Types of Casing Strings

Wells typically use multiple concentric casing strings, each with a specific purpose. The table below summarizes the main types: