Oil casing is a steel pipe used to support the wall of oil and gas wells to ensure the normal operation of the entire oil well during the drilling process and after completion. Each well uses several layers of casing according to different drilling depths and geological conditions. After the casing is lowered into the well, cement is used for cementing. Unlike oil pipes and drill pipes, it cannot be reused and is a disposable consumable material. Therefore, the consumption of casing accounts for more than 70% of all oil well pipes. Casing can be divided into guide tube, surface casing, technical casing and oil layer casing according to its use.
Oil-specific pipes are mainly used for drilling oil and gas wells and transporting oil and gas. It includes oil drill pipe, oil casing and pumping pipe. Oil drill pipe is mainly used to connect drill collars and drill bits and transmit drilling power. Oil casing is mainly used to support the well wall during drilling and after completion to ensure the normal operation of the drilling process and the entire oil well after completion. Pumping pipe mainly transports oil and gas from the bottom of the oil well to the ground.
According to the strength of the steel itself, casing can be divided into different steel grades, namely J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. Different well conditions and well depths require different steel grades. In corrosive environments, 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 performance.
API 5ct k55 seamless steel casing tube
