The shale gas migration capacity of the Qiongzhusi Formation: Implications for its enrichment model.

This article focuses on the migration mechanisms and enrichment models of shale gas in the ⑤ and ⑥ layers of the Qiongzhusi Formation within the Sichuan Basin's Deyang–Anyue rift trough. Using analyses of pore structure, mineralogy, and thermodynamic conditions, the study finds that although transitional and slip flow pores dominate in number, Darcy flow contributes most significantly to shale gas migration capacity due to the formation's deep burial and overpressure conditions. The ⑤ layer exhibits higher hydrocarbon generation potential and migration ability than the ⑥ layer, making it more gas-rich, while variations in migration capacity across the rift trough and its edges influence gas content distribution. The findings suggest that exploration and development of silty shale gas should prioritize both the exterior and interior regions of the rift trough, considering dynamic migration processes alongside traditional static enrichment factors.