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.
formations. With deeper downhole depth than J55 and K55 types, it can be applied for the exploitation of middle-level oil and gas.
methane extraction, and geothermal wells.
on both inner and outer surfaces of the product. All these defects should be completely removed, and the removed depth must not exceed 12.5% of nominal wall thickness.
any burr, tear or other defects that may have a negative impact on the strength and close connection.