API-5CT N80 oilfield casing pipe contains N80-1 and N80-Q types. Those two materials are absolutely consistent regarding the chemical composition and mechanical attributes, they are just various in the heat treatment.

During heat treatment, N80-1 steel is treated by normalizing and tempering, while N80Q steel is treated by quenching and tempering. Therefore, the collapsing strength and internal pressure strength of N80Q are higher than that of N80-1. N80-1 or N80Q should be clearly shown by the designer when N80 casing is selected.

As its mechanical properties are higher than J55 and K55 types, it may very well be utilized to certain a little more challenging formations. With deeper downhole depth than J55 and K55 types, it can be applied for the exploitation of middle-level oil and gas.

Due to the high capability of N80 material, those API-5CT casing pipes are broadly applied in natural gas as well as coal bed methane extraction, and geothermal wells.