win德赢

Abstract: Hydraulic fracturing-induced casing deformation and fault activation have greatly hindered the safe and efficient development of shale oil and gas resources. In this study, statistical analysis, physical tests, and numerical simulation methods are used to comprehensively analyze hydraulic fracturing-induced fault activation and casing deformation processes. This study is based on the Longmaxi Formation of LZ block, a deep shale gas reservoir in the southwest Sichuan Basin (China), as a geological background. A large amount of field data on fracturing from the LZ Block is counted, and the main influencing factors are analyzed. The main factors of hydraulic fracturing-induced fault slip are (from strong to weak) parameters related to fluid injection volume, parameters related to segments and clusters, and parameters related to injection rate. Combined with physical experiments and numerical simulations, the fault activation law during fracturing has been studied. The degree of casing deformation and fault slip are linearly correlated. For hydraulic fractures to cross faults is very difficult, fault activation and casing deformation can only be mitigated as much as possible. We find that the number of clusters per segment and the injection rate are negatively correlated with the fault slip distance. Reducing the fluid injection volume can mitigate the fault slip distance. Therefore, low injection rates, low fluid volumes, and more clusters per segment are recommended for fracturing in high-risk segments. It is important to note that the scale and risk of fault activation induced by well-factory fracturing is much higher compared to single-well fracturing. In situations with extremely high risk, the injection volume should preferably not exceed 800 m3 to minimize the risk of geological and casing deformation.