Corrosion Evaluation Method of Injection-production String Under the Joint Action of Alternating Load and Corrosive Medium

Abstract

The invention provides a method for evaluating the corrosion of injection-production strings under the combined action of alternating loads and corrosive media. The method includes: collecting the basic parameters of the injection-production wells of the gas storage; establishing a finite element solid model, according to the operating parameters of the injection-production conditions, loading the finite element solid model with the injection-production temperature and injection-production pressure as boundary conditions, and obtaining The axial load borne by the injection-production string is obtained to obtain the axial load spectrum; different experimental schemes are designed; the environment where alternating loads and corrosive media act together is simulated, and the axial load is applied to the injection-production string for simulation experiments; The experimental injection-production string was subjected to a dynamic slow tensile test, and the stress-strain curve was recorded until the injection-production string was broken, and the fracture microstructure of the broken injection-production string was analyzed; according to the stress-strain curve and The results of fracture microscopic morphology analysis show the combined effect of alternating load and corrosive medium on the injection-production string. This method can simulate the environment of alternating load and corrosive medium interaction, and evaluate the strength performance of the injection-production string.

Description

technical field [0001] The invention relates to a method for evaluating the corrosion of an injection-production string under the joint action of alternating loads and corrosive media, and belongs to the technical field of natural gas exploitation engineering. Background technique [0002] In recent years, the gas storage business has become an important business of CNPC. A large number of depleted gas reservoir type and salt cavern type gas storages have been continuously constructed and put into operation. In the gas storages that have been put into production, the injection and production wells have annular pressure problems to varying degrees, and the main reason is the failure of the injection and production strings. Paying attention to the design of injection-production string is a very important method to avoid or reduce the probability of failure. [0003] At present, the design of the injection-production string fails to take into account that the injection-produc...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the above technical problems, the object of the present invention is to provide a method for evaluating the corrosion of injection-production pipe strings, which can realize the material evaluation of injection-production pipe strings under injection-production conditions by simulating the environment where alternating loads and corrosive media interact together , which can make up for the lack of corrosion evaluation of injection-production strings under the combined action of corrosive media and alternating loads, provide technical means for the safety of gas storage injection-production strings, and reasonably optimize the material of injection-production strings, and further reduce injection-production strings. Hidden dangers and risks of pipe string failure

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