Method for evaluating formation and evolution of continental facies mud shale oil in large freshwater lake basin

Abstract

The invention discloses a method for evaluating formation and evolution of continental facies shale oil of a large freshwater lake basin, which is used for evaluating shale oil content recovery, a longitudinal dessert layer and a planar dessert area by utilizing a method of combining conventional core taking and geological experiment analysis of drilling, pressure-maintaining closed coring, frozensample oil content calibration and a logging technology. A continental facies shale oil formation and evolution evaluation mode is established by utilizing parameter indexes such as depth, Ro, kerogen, chloroform asphalt A, free oil quantity, absorbed oil quantity, gas-oil ratio and the like, so requirements of shale oil exploration are met. The method comprises the following steps of evaluatingthat a large amount of absorbed oil is converted into free oil at Ro1.1%-1.6%, the method is the most favorable stage of shale oil formation, the shale oil in the maturation and high maturation stagesis 1.5-3.5 times of that in the classic oil production mode, the optimal selection and exploration breakthrough of the shale oil dessert in the Songliao basin are guided, the exploration depth can beexpanded to 2600 m, the area of the dessert area is expanded by 1.2 times, and a material foundation for large-scale exploration of the continental facies mud shale oil in the large-scale freshwaterlake basin is laid.

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 evolution 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, leading to a worldwide upsurge in shale oil exploration and development, and the global technically recoverable reserves of shale oil can reach 4.86×10 10 t. China has carried out the exploration and development of mud shale oil in many lacustrine basins, and has achieved industrial oil flow and positive progress in many wells in Songliao, Ordos, Bohai Bay, Nanxiang, Junggar Basins, etc., showing that mud shale Good prospects for oil exploration and development. The research on the formation and evolution evaluation of shale oil is to solve the scientifi...

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Problems solved by technology

[0004] The present invention overcomes the problem that the existing methods in the background technology cannot solve the formation and evolution of continental mud shale oil in large freshwater lake basins and effectively guide the exploration of mud shale oil, and provides a large freshwater lake basin continental mud shale Oil Formation and Evolution Evaluation Method

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