Analysis of the Impact of Perforation Shock on Mechanical Behavior of Casing in Shale Horizontal Well

Summary In shale horizontal well completion engineering, perforating the casing is a common method to allow oil and gas to flow into the wellbore. However, the perforation process can compromise the integrity of the casing structure. To investigate the impact of perforation-induced shock on the stress distribution of the casing, we developed a simplified simulation model to represent the perforation process, and confirmed the validity of the simulation model through a detonation perforation experiment. Subsequently, we analyzed the effects of perforation parameters on the stress distribution of the casing during the perforation shock. The results indicate that the perforation process generates a compressive stress region around the perforation hole, forming an annular stress pattern. Further, we found that the cluster density and phase angle mainly affected the interhole stress levels in spiral directions. Based on these findings, low-risk perforation strategies for different perforation parameters are proposed. Overall, this study provides insights into the mechanical behavior of the casing during perforation and offers a reference for optimizing casing perforation design.