Casing pipe is most often used for underground boring to encase and protect pipe. As we all known,tube is used for conveying gas,water,and oil in both and natural gas industries etc.
In the oil industry the main using of the casing is conveying oil. Casing is a large-diameter pipe that serves as the structural retainer for the walls of oil and gas wells, or well bore. It is inserted into a well bore and cemented in place to protect both subsurface formations and the well bore from collapsing and to allow drilling fluid to circulate and extraction to take place. Casing is a steel tube supporting oil and gas well. According to different drilling depth and geological conditions, the casing layer is different. Oil casing should be used with cement, to fixed. Steel Casing Pipes have smooth wall & minimum yield strength of 35,000 psi.
According to the using of the casing, it can be divided into three kinds ：surface casing ,technical casing and oil laying .And whats more ？Casing is different from the tubing and drill pipe and it belongs to one time consuming material which can not be used repeatedly.So it still serve as an important role in the oil industry.