seamless casing pipe is a steel pipe used to support the wall of oil and gas wells to ensure the normal operation of the entire oil well after the drilling process and completion. Each well uses several layers of casing according to different drilling depths and geological conditions. Cement is used to cement the well after the casing is run down. It is different from tubing and drill pipe and cannot be reused. It is a one-time consumable material. Therefore, casing consumption accounts for more than 70% of all oil well pipes.
Casings can be divided into pipes, surface casings, technical casings and oil casings according to their usage.
Different types of casing used in the process of oil extraction:
Surface oil casing: protect the well from being contaminated by shallow water and gas layers, support wellhead equipment and maintain the weight of other layers of the casing.
Technical oil casing: Separate the pressures at different levels so that the drilling fluid can circulate normally and protect the production casing. Install anti-burst devices, leak-proof devices and liners in the well.
Reservoir oil casing: to export oil and natural gas from the reservoir below the surface. It is used to protect wells and stratify drilling mud. When the oil casing is produced, the outer diameter is usually 114.3 mm to 508 mm.
According to SY/T6194-96 "Petroleum Casing", the types and packaging of petroleum casing are divided into short-threaded casing and its coupling and long-threaded casing and its coupling.