API 5CT N80 casing pipe is the lifeline to keep the well running. Due to different geological conditions, the downhole stress state is complex, and the comprehensive action of pull, pressure, bend and torsion stress on the tube body, which puts forward higher requirements for the quality of API 5CT N80 casing pipe. If the API 5CT N80 casing pipe itself is damaged for any reason, it could result in the loss of production or even the death of the entire well.
API 5CT N80 casing pipe has the following characteristics:
(1) According to SY/T6194-96, API 5CT N80 casing pipe length is indefinite, and its range is 8-13m.However, API 5CT N80 casing pipe sleeves of no less than 6M are available in quantities not exceeding 20%.
(2) The internal and external surfaces of API 5CT N80 casing pipe shall not be folded, textured, separated, cracked, rolled and scarred.These defects should be completely removed at a depth not exceeding 12.5% of the nominal wall thickness.
(3) The outer surface of the collar shall not have any defects such as folding, hairline, separation, crack, rolling and folding, scar, etc.
(4) The surface of API 5CT N80 casing pipe and collar threads shall be smooth and shall not allow burr, tear or other defects sufficient to affect the strength and tight connection of the thread.