What is the oil casing?

Special oil pipe is mainly used for drilling oil and gas wells and transporting oil and gas. It includes oil drilling pipe, oil casing pipe and oil extraction pipe. Oil drilling pipe is mainly used to connect drill collar and bit and transmit drilling power. Oil casing is mainly used to support the well wall during and after well completion, so as to ensure the normal operation of the whole oil well during the drilling process and after completion. The pumping tube mainly transports oil and gas from the bottom of the oil well to the surface.

Oil casing is the lifeline of oil well operation. Due to the different geological conditions, the downhole stress state is complex. The comprehensive action of tensile, compressive, bending and torsional stresses on the pipe body puts forward higher requirements for the quality of oil casing itself. Once the casing itself is damaged due to some reason, the production of the whole well may be reduced or even scrapped.

According to the strength classification of steel, oil casing can be divided into different grades, namely J55, K55, N80, L80, C90, T95, P110, q125, V150, etc. Different well conditions and well depths lead to different steel grades. In corrosive environment, the oil casing itself is required to have corrosion resistance. In complex geological conditions, casing is also required to have anti collapse performance.