Study in deep shale gas well to prevent shoulder protruding packer with high pressure sealing.

• Proposes a kind of high-pressure sealed preventing shoulder protruding (HPS-PSP) structure packer. • The comparison between theory and experiment verifies the accuracy of the model calculation results. • The optimization analysis of the structural parameters of the packer rubber is carried out. • The HPS-PSP packer effectively solves solves the problem of shoulder convexity and low sealing pressure of the original structure. Shale gas is a kind of unconventional oil and gas resources that can be exploited in shale strata. According to the evaluation of oil and gas resources carried out by the ministry of land and resources of China, the geological resources of shallow shale gas with a depth of 4500 m are 122 trillion cubic meters. However, the overall geological conditions of shale gas in China are complex and the buried depth is too large. For deep shale gas wells with vertical depth of more than 3500 m, problems such as shoulder protruding, tearing, crushing and insufficient sealing performance of rubber tube are caused by high-pressure fracturing. Aiming at the above problems, proposes a high-pressure sealed preventing shoulder protruding (HPS-PSP) structure packer. Based on the deformation theory of rubber tube, the finite element calculation model of packer tube under the setting condition was established. The influence of the thickness of the prevent shoulder protruding ring and the height of the trapezoidal ring groove and the length of the trapezoidal upper base on the sealing performance of the rubber tube were analyzed. The results show that: The HPS-PSP packer can effectively solve the problems of protrusion of rubber tube shoulder and insufficient sealing performance, and the contact pressure increases by 60.1% compared with the conventional one. The research work provides a method to improve the sealing performance of packer rubber, which is of great significance to improve the applicability of packer in deep shale gas fracturing operation. [ABSTRACT FROM AUTHOR]