oil casing definition

The special oil pipe is mainly used for the drilling of oil and gas wells and the transportation of oil and gas. It includes oil drilling pipes, oil casings, and oil sucking pipes. Oil drill pipes are mainly used to connect drill collars and drill bits and transmit drilling power. The oil casing is mainly used to support the well wall during the drilling process and after the completion of the well, so as to ensure the drilling process and the normal operation of the entire oil well after the completion of the well. The oil pipe mainly transports the oil and gas at the bottom of the oil well to the surface.

Oil casing is the lifeblood of keeping oil wells running. Due to different geological conditions, the downhole stress state is complex, and the comprehensive action of tension, compression, bending and torsional stress acts on the pipe body, which puts forward higher requirements for the quality of the casing itself. Once the casing itself is damaged for some reason, it may lead to the reduction of production of the whole well, or even to be scrapped.
According to the strength of the steel itself, the casing can be divided into different steel grades, namely J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. The well conditions and well depths are different, and the steel grades used are also different. In a corrosive environment, the casing itself is also required to have corrosion resistance. In places with complex geological conditions, the casing is also required to have anti-collapse properties.

Oil Tubing Sizes and Weight Chart

Classification of oil casing

Casing can be divided into: conduit, surface casing, technical casing and oil casing according to the usage.

According to the strength of the steel itself, the casing can be divided into different steel grades, namely J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. The well conditions and well depths are different, and the steel grades used are also different. In a corrosive environment, the casing itself is also required to have corrosion resistance. In places with complex geological conditions, the casing is also required to have anti-collapse properties.

Oil casing use

Oil casing is a steel pipe used to support oil and gas well walls to ensure the normal operation of the entire oil well after the drilling process and completion. Several layers of casing are used for each well according to different drilling depths and geological conditions. Cement cementing should be used after the casing is put into the well. It is different from the tubing and drill pipe, which can be reused and is a one-time consumable material. Therefore, the consumption of casing accounts for more than 70% of all oil well pipes.

Petroleum casing standard

API SPEC 5CT-2011 “Specification for Tubing and Casing” is issued by the American Petroleum Institute – a standard on oil casing, which is used worldwide and is mainly used for oil pipe, tubing and casing.

Features of the casing manufacturer API 5CT pipes we manufacture

• Excellent comprehensive mechanical properties
• High connection strength and sealability
• High precision in size and shape
• Good corrosion resistance
• High collapse strength
• Constant mechanical properties at high temperature