Features Of Seamless Tubing And Casing

Tubing is a pipe that is run into the oil well casing during normal production of the oil well. Casing is the pipe that is lowered into the well after drilling is complete. Tubing and casing are both widely used in oil and gas industry. Today, we are going to talk about features of seamless tubing and casing.

Main Functions Of Tubing And Casing:

1. Reinforce the well wall to prevent formation collapse;

2. Separate different oil layers and water layers to achieve layered mining;

3. Conducive to the implementation of fracturing, acidification operations and maintenance operations;

4. Form an oil flow channel and cooperate with the oil pipe to achieve the purpose of oil production.

The failure of seamless petroleum casing is one of the major problems encountered in various fields, among which the failure of threaded joints is the most serious. According to statistics, about 64% of threaded connection accidents occur due to oil casing failure. Domestically, this figure is as high as 86%. The fixed oil casing threaded joint is the weak link of the oil casing string. Therefore, improving the quality of threaded connections is the guarantee for columns. key factors of quality. The stress distribution used in oil casing threads directly determines the strength of the connecting string.

The stress distribution in the studied section not only provides manufacturers with a basis for optimizing oil casing thread design and predicting casing and tubing performance. The sequence is: after the oil well is drilled, place the casing, seal the casing and the well wall with cement, and put the oil pipe into the casing. The oil pipe is equipped with packers, pumps and other downhole tools. Insert the sucker rod into the oil pipe, and the sucker rod pulls the piston of the pump to reciprocate up and down. In this way, the oil is pumped to the surface.

Seamless steel pipes are the most commonly used pipes in oil and gas exploration. They rely on internal and external threaded male fasteners to operate a series of deeply buried underground steel pipes. Oil well casing is the lifeline of its quality, which directly affects the success of drilling operations and the service life of oil and gas wells, involving the economic benefits of oil fields and manufacturers.

The seamless oil casing joint is a male and female snap contact surface composed of an external thread male buckle and a buckle internal thread nut. This is a spiral surface, and the matching force with the oil pipe is relatively complicated. In addition to the tightening torque generated by contact pressure, it also bears loads such as tension and pressure (caused by oil, gas or other media). The joint force analysis of petroleum casing involves the complexity of material nonlinearity, geometric nonlinearity and contact friction conditions. It is difficult to establish a complete and accurate mathematical model and solve it analytically.