Oil well pipe occupies an important position in the oil industry and is the foundation of the oil industry. The status of oil well pipe in the oil industry is not only reflected in the large amount and high cost, but more importantly, its quality and performance are closely related to the development of the oil industry.
Oil well pipe has harsh service conditions. For example, the tubing string and casing string usually have to withstand hundreds or even thousands of atmospheres of internal or external pressure, hundreds of tons of tensile load, high temperature and harsh corrosive media.
Oil-specific pipe has very harsh service conditions, and its quality requirements are much stricter than those of general seamless pipes. It must be produced and inspected in accordance with special standards or technical conditions. At present, the production and inspection standards widely used for oil-specific pipes at home and abroad are mainly based on the American Petroleum Institute, that is, API standards. Casing and tubing adopt API SPEC5 CT standard, drill pipe adopts API SPEC5 standard, and drill pipe joint adopts API SPEC7 standard.
The casing steel grades listed in API SPEC5 CT standard are: H40, J55, K55, N80, M65, L80, C90, C95, T59, P110, Q125; casing steel grades are: H40, J55, N80, L80, C90, T59, P110.
Casing and Tubing Chemical composition in API 5CT
Mechanical Properties Tensile Strength and Yield Strength
