四川盆地侏罗系凉高山组沉积特征及演化规律OA

Well Ping'an-1 of Jurassic Lianggaoshan Formation in northeastern Sichuan Basin has made significant breakthroughs,revealing that Jurassic Lianggaoshan Formation has abundant shale oil and gas resources.However,less research on the overall exploration of Lianggaoshan Formation across the whole basin has constrained the prog-ress of shale oil and gas exploration in Lianggaoshan Formation.Based on field outcrop,core,thin sections,elec-tric logging and mud logging data,the overall sedimentary characteristics and areal extention of sedimentary facies in Lianggaoshan Formation are clarified by means of rock types classification,single-well sedimentary microfacies classification,well-tie facies correlation and establishment of sedimentary model.The results show that the structure in sedimentary period of Jurassic Lianggaoshan Formation is relatively unstable,forming an incomplete long-term water inflow and regression cycle,which includes lowstand system tract,lacustrine transgressive system tract and incomplete highstand system tract.Sediments in Lianggaoshan Formation are mainly lacustrine silt-fine sandstone and mud shale,with small amount of shell limestone locally developed and generally being a lake-delta sedimentary system.Vertically,1st sub-member of upper Lianggaoshan Formation and 2nd sub-member of upper Lianggaoshan Formation are favorable exploration intervals,and horizontally,Pingchang-Yingshan area is favorable exploration ar-ea.The research provides support for further exploration and development of shale oil in Lianggaoshan Formation.