South Anze Structure and Its Control on Coalbed Methane Aggregation in the Qinshui Basin and the Mechanism of Syncline Gas Enrichment in the Qinshui Basin

The phenomenon of coalbed-methane synclinal accumulation in the Qinshui Basin has been widely reported, but it mainly observed core block Syncline. questions arise: does this exist wing Syncline and, if so, what is mechanism behind it? Further study required to answer these questions. This paper focuses on South Anze No. 3 coal seam as an example. It conducts a systematic sorting geological characteristics and analysis effects structural assemblage characteristics, genetic mechanisms, control accumulation. Additionally, examines basin structure evolution during critical period Basin, well gas adjacent areas, order discuss gas-rich syncline Basin. Key insights obtained from include following: (i) whole nosing that plunges west east superposes secondary folds faults different directions. Four deformation zones can be identified based assemblage, including NEN-oriented compressive structures, ENE-trend shear fractures, EW-trend folds. formation area attributed compression Indosinian Yanshanian, fault inversion Himalayan period. (ii) fracture located uplift low CBM (coalbed methane) content due diffusion extension. combination NEN-trend “ejective folds” south high-value content. further verified law also applicable (iii) Since Syncline, main extensional environment below neutral plane, resulting dissipation coalbed methane. During its history, surface water penetrated aquifer above through two channels: plane anticline fracture. A hydrostatic pressure seal formed superimposed upon it, which cause enrichment (iv) Weak focus global exploration development. proposed provide ideas references for understanding type basin.