*2.1. Geology*

The West Sichuan depression, bounded by the Longmenshan thrust and Longquanshan uplift belts, is a key area of natural gas exploration in China [30]. The maximum buried depth of the Xujiahe Formation exceeds 4.5 km, and the average thickness of the target layer is approximately 120 m. The work area was subjected to multi-stage Indosinian, Yanshan, and Himalayan tectonic movements, which resulted in diverse structural fractures that are controlled by complex diagenesis processes. A mechanical compaction is an aspect of diagenesis that destroys the primary pores. The sedimentary facies are mainly about the braided river delta facies. The channels overlap with each other from different periods, forming a longitudinal superposition and plane contiguous sand bodies [31].
