Formation and enrichment evaluation method for continental facies mud shale oil in large freshwater lake basin

Abstract

The invention discloses a formation and enrichment evaluation method for continental facies mud shale oil in a large freshwater lake basin. According to the method, the method comprises the steps of:utilizing shale oil exploration drilling coring, lithology and lithofacies accurate description and geological experiment matching analysis, carrying out formation and enrichment evaluation on continental facies shale oil; respectively adopting parameters indexes such as depth, Ro, diagenetic stage, kerogen, free oil quantity, the total porosity, organic cleavage seams, inorganic cleavage seams, areservoir evolution mode, a shale oil evolution mode, establishing a matching relationship among a continental facies shale oil formation and evolution mode, a reservoir stratum pore formation and evolution mode and a reservoir stratum evolution history and generation evolution history; and determining for the first time that a window and a secondary pore development zone which are favorable forformation of shale oil are formed in the late middle diagenetic stage Ro1.1%-1.6%, so that necessary conditions are created for large-scale aggregation of shale oil through high coupling in time and space, optimal selection and exploration breakthrough of the continental facies shale oil dessert in the Songliao basin are guided, the lower limit of the exploration depth can be expanded to 2,600 m,and the dessert area is expanded to 13,000 km<2> from 5,800 km<2>.

Description

technical field [0001] The invention relates to the technical field of unconventional oil and gas exploration in oil fields, in particular to a method for evaluating the formation and enrichment of continental mud shale oil in large freshwater lake basins. Background technique [0002] The breakthrough of shale oil in North America has brought about a new round of technological revolution in the global oil and gas industry. China has achieved industrial oil flow and positive progress in many wells in Songliao, Ordos, Bohai Bay, Nanxiang, Junggar Basins, etc., demonstrating that Good prospects for exploration and development of mud shale oil. The research on the formation and enrichment evaluation of shale oil is to solve the problems of the optimal period of shale oil formation, favorable storage space and its time-space matching and enrichment, and it is an important basis for guiding shale oil layer selection and exploration deployment . For a long time, mud shale has be...

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Problems solved by technology

[0004] The present invention overcomes the problems that the existing methods in the background technology cannot solve the formation and enrichment of continental mud shale oil in large freshwater lake basins and effectively guides exploration and deployment, and provides a kind of continental mud shale oil in large freshwater lake basins Formation and Enrichment Evaluation Methods

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