Structural Analysis and Evolution Model of the Longmaxi Formation in the Yanjin–Junlian Area of the Southern Sichuan Basin, China

The Longmaxi Formation in the southern Sichuan Basin is an important target for shale gas exploration and development. characteristics stages of structural development significantly impact preservation enrichment. Taking Yanjin–Junlian area as example based on results surface underground analysis, fluid inclusion tests, apatite fission track experiments, burial-thermal evolution history a comprehensive study was carried out, model developed. (1) has been affected by multistage movements exhibits compounding superposition corresponding to different stages. formation tracks folds faults multidirectional extrusion stresses near SN, NE, EW. There are three Formation, strikes nearly EW, SN. (2) Three distribution intervals homogenization temperature ranges fracture fillings 161–195°C, 121–143°C, 74–105°C. thermal simulation reveals that experienced tectonic movement after its formation. (3) were clearly this area: late Jurassic–Palaeocene (55 ± 5–38 2 Ma), Eocene–early Miocene (38 2–15.5 3.5 Miocene-present (15.5 Ma–present). Thus, compound system with superimposed deformations directions at formed area. (4) A established conjunction analysis geomechanical theory. have guiding significance evaluation conditions accumulation