Introduction about Grade of Casing&Tubing

There are 20 different steel grades and types of oil casing and tubing in H40, J55, K55, M65, N80, L80, C90, T95, C95, P110, Q125. In order to distinguish the strength and thread type of different steel grades , using different color codes and symbols to represent the oil, steel grade and thread of the casing. The two or three digits behind the color code and English letters indicate the minimum yield strength of oil and casing steel grades, such as J55, which indicates that the minimum yield strength is 55,000 pounds/inch 2 (379Mpa) and the highest is 80,000 pounds/inch 2 ( 552Mpa), the minimum yield strength of P110 is 110000 lb/in2 (758Mpa) and the highest is 140000 lb/in2 (965Mpa). H, J, K, N represent general strength oil casing, C, L, M, T represent limited yield strength oil casing, which have certain resistance to sulfur corrosion.

The steel grade of the oil casing refers to the yield strength of the material, such as H40 means that the strength is 40*1000/145MPa=275.86MPa

Locally, J55 is generally used for surface casing, N80 for oil layer casing, P110 for high-pressure layers, or P110 for the upper part of wells that are relatively deep. There are 20 different steel grades and types of oil casings in H40, J55, K55, M65, N80, L80, c90, T95, C95, P110, Q125, in order to distinguish the strength and thread type of different steel grades , using different color codes and symbols to represent the oil, steel grade and thread of the casing. The two or three digits behind the color code and the English letter indicate the minimum yield strength of the steel grade of the oil and casing, such as J55, which indicates that the minimum yield strength is 55,000 pounds/inch 2 (379Mpa and the highest is 80,000 pounds/inch 2 (552Mpa ), the minimum yield strength of P110 is 110,000 pounds/inch 2 (758Mpa, the highest is 140,000 pounds/inch 2 (965Mpa). H, J, K, N represent general strength oil casing, C, L, M, T represent limited yield strength Oil casing has a certain resistance to sulfur corrosion.