It is mainly used to support the well wall during and after drilling to ensure the normal progress of the drilling process and to ensure the normal operation of the entire oil well after drilling.2. Types of N80 petroleum casing
According to the SY / T6194-96 "Petroleum Casing" standard, the types and packaging of petroleum casings are divided into two categories: short-thread casings and their couplings and long-thread casings and their couplings. According to SY / T6194-96, household casings should be bundled with steel wire or steel belt. The exposed part of the thread of each sleeve and coupling should be tightened with a protective ring to protect the thread.
3. Specification of N80 petroleum casing
SY / T6194-96 stipulates that the length of oil casings made in China is variable, with a range of 8m / 13m, but casings of not less than 6m can be provided, and the number should not exceed 20%.
4. Appearance of N80 petroleum casing
The inner and outer surfaces of the oil casing shell should be free of folds, hairline, delamination, cracks, creases and crusts. These defects should be completely removed, and the removal depth should not exceed 12.5% of the nominal wall thickness.
5. Quality of N80 petroleum casingThe surface of the casing and the connecting thread should be smooth, and there should be no burrs, tears or other defects sufficient to cause the thread to break and affect the strength and tight connection.