api 5ct l80 13cr oil casing and tubing
In API SPEC 5CT standard, the steel grades of casing and tubing indicate their yield strength and characteristics. Steel grade marking is usually represented by 1 letter and 2 or 3 numbers, such as N80. In most cases, according to the order of the letters in the alphabet, the later the letters, the greater the yield strength of the pipe. For example, the yield strength of N80 first grade steel is greater than that of J55: the numerical symbol is determined by the minimum yield strength of the pipe expressed in thousands of pounds per square inch. For example, the minimum yield strength of N80 steel grade is 80klb/in2
Oil casing steel grades listed in API SPEC 5CT standard include H40, J55, K55, N80, M65, L80, C90, C95, T95, P110 and Q125;
Casing is a large-diameter pipe that serves as the structural retainer for the walls of oil and gas wells or wellbore.
It is inserted into a well bore and cemented in place to protect both subsurfa…