Potential Evaluation Of Shale Oil Resources In The Chang 7member Of The Ordos Basin

The Cenozoic organic-rich mud shale,which is widely distributed in China’s continental basins,is in the stage of oil production and has good prospects for shale oil exploration.Based on the study of the reservoir characteristic,geochemical characteristics,shale oil oiliness and mobility parameters of the lower of chang 7 in ordos basin,the distribution and enrichment characteristics of continental shale oil are analyzed,and the amount of shale oil resources is calculated.Generally speaking,the deposit thickness of shale in the lower of chang 7sub-segment of ordos basin,is less than 50m,TOC model of theΔlog R prediction is established by logging curve analysis,the maximum of TOC is more than 30%,and the average is 10.5%,the type of organic matter is type II₁and II₂,the Ro is mainly between 0.6%～1.2%,and has a good potential of shale oil exploration.The shale of the lower of chang 7 is divided into argillaceous shale,mixed shale,and sandy shale,the argillaceous shale is the least,and the sandy shale has the biggest pore.Chloroform asphalt A and pyrolysis hydrocarbon S₁are the main geochemical parameters characterizing oil content.The chloroform asphalt A and the pyrolysis hydrocarbon S₁were corrected.Combined with the gold tube experiment,the recovery coefficient of light hydrocarbons of chloroform asphalt A and pyrolysis hydrocarbon S1 is between 0.1 and 0.4,which increases with the increase of maturity,and the recovery coefficient of heavy hydrocarbons is between 1.8 and 14.13,which decreases with the increase of maturity.The paper studies the OSI index of quantitative parameters of movable shale oil,showing that it has a good mobility.The viscosity and residual pressure mobility of the shale oil were analyzed.,the average viscosity of the shale oil is 6.43 m Pa·s,the residual pressure distribution of the lower of chang 7 is benefit for the flow of shale oil.Using Petro V,we can calculate the total shale oil resources in the lower of Chang 7 are 442.76×10⁸t,the resources in the shale is 423×10⁸t,and the resources in the tight sandstone is 19.76×10⁸t.The highest oil resource intensity of the lower of Chang 7 in the basin can reach 490×10⁴t/km²,and the highest intensity of tight sandstone resources in the basin can reach 25×10⁴t/km².The resource level in the enrichment phase is 398×10⁸t,the low efficient enrichment resource is 40×10⁸t,and the inefficient enrichment resource is 4.76×10⁸t.The movable shale oil resource is94.2×10⁸t.