How to connect the octg casing?

The octg casing adopts threaded direct connection, and the male end is connected with the female end. When connecting, whether the sealing performance of the threaded part of the casing is reliable is the key factor to ensure the normal production of the oil well.

The sealing structure of the new threaded oil casing adopts metal-to-metal contact sealing, which does not cause clearance problems and has very reliable sealing performance; special threaded oil casings have been widely used in industrial equipment, especially in high-pressure oil and gas wells . However, these emerging threaded sleeves have very strict requirements on tightening torque. Generally, there are three values of maximum torque, optimum torque and minimum torque.

The three values of different threaded oil casings are also different. Some special threads have a small range between maximum and minimum torque. In the actual oil casing operation, the tightening torque must be strictly within this range, if the maximum torque value is exceeded, the sealing surface of the threaded oil casing will be damaged. If it is less than this torque value, the metal sealing surface of the casing cannot have good contact with the metal. The surface will not act as a seal at all, so you must pay attention to this when using it.

Oil casing connection method:

1. External thickening connection method: one section of the pipe is thickened with internal thread fasteners, and the other end is external thread fasteners. When joined together, the sleeves have a smooth inner surface.
2. Direct connection method: the internal and external threads at both ends of the pipe are directly connected, and the inside and outside of the pipe are smooth.
3. Connection method of the pipe: the two ends of the pipe are internally threaded buckles, and the pipe is connected. The exterior is smooth when attached.
4. Coupling connection method: both ends of the pipe are externally threaded fasteners, which are connected by external hoops. Once connected, the interior becomes a smooth surface. In addition, recently, the oil casing pipe adopts the method of welding joints to make the inner surface of the welded pipe smooth.

Weight calculation:
Kg/m = [(outer diameter-wall thickness)*wall thickness]*0.02466

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