四川盆地合川地区走滑断裂特征及其油气地质意义OA

In order to clarify the growth characteristics of strike-slip fault system in Hechuan area and reveal its con-trol on natural gas accumulation in Permian Maokou Formation,based on 3D seismic data and drilling data,a com-prehensive analysis method combining seismic processing interpretation and geological experiment is adopted.Through fine fault interpretation technology,combined with experimental methods such as seismic attribute analy-sis,U-Pb dating of fault cement and gas-source comparison,development characteristics and hydrocarbon geologi-cal significance of strike-slip faults in Hechuan area are studied.The results show that during Maokou Formation sedimentary period,Hechuan area was dominated by inherited development of near EW and near NW-strike faults,followed by the development of near NE and NNE-strike faults.Areal distribution shows 5 types of strike-slip fault combination styles,including linear structure,floral structure,braided structure,en echelon structure and horse-tail structure.Spatial distribution is characterized by planar segmentation,en echelon distribution and multi-stages activities,and its growth process has experienced 3 stages of extension and 2 stages of compression.The inherited activity of near EW and near NW strike-slip faults,combined with penetration reflux effect during shallow burial stage of Maokou Formation,jointly control the formation of matrix dolomite and saddle dolomite.Meanwhile,this type of fault connects with deep Qiongzhusi Formation source rocks,forming a vertical three-dimensional transport-ing system,which is a key controlling factor for the enrichment and accumulation of natural gas in Maokou Forma-tion.The research provides effective support for further exploration deployment in Hechuan area.