中国东西部陆相页岩油地质特征差异性分析及其对富集规律影响OA北大核心CSTPCD

The exploration area of Shengli Oilfield was studied,and the difference in geological characteristics of shale oil in conti-nental lake basins in eastern and western China and its influence on the enrichment law were systematically compared.Controlled by paleogeomorphology,paleoclimate,paleowater medium,and other factors in Eocene The Upper Submember of 4th Member of Eo-cene Shahejie Formation(Es4U)-The Lower Submember of 3rd Member of Eocene Shahejie Formation(Es3L)of Jiyang Depression,the organic-rich lamellar carbonate shale was widely distributed.The synergistic evolution of hydrocarbon generation of organic-rich clay lamina and reservoir formation of carbonate-rich lamina provided favorable conditions for the large-scale enrichment of free hy-drocarbons.The strong rifting of Fengcheng Formation in Hashan area in the northwest margin of Junggar Basin led to strong volca-nic activity.Under the combined influence of volcanic eruption materials and paleoclimate,large-scale distribution of organic-rich lamellar alkali-bearing felsic shale lithofacies was observed.More felsic minerals were formed during the evolution of hydrocarbon generation and reservoir formation,accompanied by a large number of matrix dissolution pores and intercrystalline pores,which laid an essential foundation for shale oil enrichment.In the process of multi-stage thrusting in Hashan area,the quasi-in-situ system continued to generate hydrocarbons,with more oil and less gas.The relatively good storage conditions,as well as abnormal high pressure caused by structural overburden pressure and pressurization due to hydrocarbon generation,provide necessary conditions for high shale oil production.Under the background of salt water in Haiji Lake,Lucaogou Formation in the southeastern margin of Junggar Basin was affected by volcanic debris and microorganisms to form the primary lithofacies combination type of organic-rich lamellar shale and organic-poor interlayer dolomite.The organic-rich shale of Lucaogou Formation in the piedmont zone around Bogda Mountain has entered the mature evolution stage,and the structural stability area in the exploration area of Shengli Oilfield was a potential area for shale oil exploration.