Petroleum special pipes are mainly used for drilling oil and gas wells and oil and gas transportation. Oil casing is mainly used to support the wellbore during driling and after completion to ensure the normal operation of the wholewell, Oi casina is the lifeline to maintain oil well operation. Because of the different aeolodical conditions.the stress state of underground is complex, and the comprehensive action of tension, compression, bending and torsion stresses acts on the pipe body, which puts forward higher requirements for the quality of casing itself. Once the casing itself is damaged for some reason, it may lead to production reduction or even abandonment of the whole well.
