Petroleum
casing pipe is a special kind of tubing that has been used for a long time. Petroleum casing string is an integral structure of oil wells, which plays the role of strengthening the wellbore, protecting the wellbore, and ensuring normal drilling. Petroleum casing is the only channel for oil and gas production. The casing's ability to resist perforation, crushing and internal pressure should be improved as much as possible to ensure the performance of petroleum casing. Field investigation and failure analysis indicate that the toughness of the oil casing has a great impact on the perforation performance. In order to seek high toughness, people began to systematically evaluate the fracture toughness and dynamic mechanical properties of reservoir oil casings, including dynamic and static fracture toughness, in order to better understand casing performance and serve the development of oil and gas wells.
Dynamic fracture toughness experiments were performed on an oscillometric impact testing machine, but there are still some problems with the curves between the transit time, market time and deflection time, and the dynamic fracture toughness experiments on an oscillometric impact testing machine. Petroleum casing manufacturers believe that it is feasible to calculate the dynamic L using the static flat method, that is, how to deal with the problems of inertial force shadow noise and vibration and dynamic deformation.
The loading rate and strain rate of static or quasi-static loads are relatively low, without taking into account the effects of fracture and deformation of the nature of the material on the fracture process brought by the elastic phase transition at high load rates and deformation, and the stress is The response speed of the strain sound is lower than the sound speed of the data, and has no effect on the deformation rate of the elastic deformation performance of the data.
But in the stage of plastic deformation, the process of plastic deformation is relatively slow.
Petroleum casing manufacturers believe that when sufficient plastic deformation requires more time, when the high load rate and strain rate exceed the critical deformation rate required for plastic deformation, the yield point of the data will pass through the process of restraint and constraint plastic deformation. Increasing the number of plastics that can reduce the hardening process is also affected.
