What are the defects of oil casing couplings?

The defects of oil casing couplings are mainly reflected in the problems that may be encountered during processing and manufacturing and actual use. The following is a specific analysis:

1. Processing deformation risk

During the processing process, if the process parameters are not strictly controlled, such as unreasonable processing temperature, pressure, speed, etc., it is easy to cause deformation of the oil casing coupling. Insufficient precision of processing equipment may also cause deformation of the coupling, affecting installation and performance.

2. Installation and sealing problems
Severely deformed oil casing couplings may cause installation difficulties or even failure to install normally, affecting the use of the entire system. In addition, processing deformation may cause the coupling to be loosely sealed, resulting in oil leakage, affecting the work efficiency and safety of the system.

3. Limited service life
Processing deformation will cause stress concentration inside the coupling, which is easy to cause fatigue damage, thereby shortening the service life. Especially in high pressure, high temperature or corrosive environments, this effect is more significant.

4. Thread processing defects
During the thread processing of oil casing pipe, due to the precision error of processing equipment, the error of detection equipment, the error of pipe body and coupling material, and the error of thread close distance, the connection strength of oil casing may be defective. For example, insufficient thread length, thread processing tolerance and other problems may affect the connection performance of the coupling.

5. Difficulty of roundness control

The roundness control of oil casing coupling is the key to ensure its connection performance. However, due to the complex structure of the coupling, the surface and size requirements are high, especially the thread diameter and sealing, which need to be strictly controlled. During the processing, if there are problems such as excessive vibration, it may cause defects such as knife marks, affecting the roundness accuracy.

Read more: Seamless casing vs. ERW casing or API 5CT Steel Casing and Tubing Chart