Evaluation Function Of Oil And Gas Resources In Wuyun Formation Of Xin'an Village In Fangzheng Fault Depression

With the advent of middle-later period in Daqing oilfield'development,the peripheral basins of Daqing exploration area,as an important replacement area for oil and gas exploration in Daqing Oilfield,have become the research focus of oil and gas exploration.In this paper,the integrated evaluation system of geology,geochemistry and basin simulation is used to evaluate and study the oil and gas resources of Xinancun Wuyun formation of Fangzheng fault depression in the peripheral area of Songliao.The aim is to provide geological basis for finding the favorable oil and gas area and"sweet spot area"of Fangzheng fault depression.Based on this,this paper systematically studies the geochemical characteristics of the source rocks,the calculation methods of the oil and gas resources and the calculation of the oil and gas resources in the Xinancun Wuyun formationof Fangzheng fault depression.The main research contents are as follows:the characteristics of the source rocks,including the organic matter type,abundance,thermal evolution degree and distribution characteristics of the source rocks in the Xinancun Wuyun formation;the comprehensive analysis and comparative study of the resource calculation methods,including Comparative analysis of the advantages and disadvantages of analogy method,statistical method and genetic method;calculation of oil and gas resources in Fangzheng fault depression,including calculation formula,calculation parameter assignment and resource calculation.The main conclusions are as follows:1.Two sets of argillaceous source rocks are developed in the Xinancun Wuyun formation in fangzheng fault depression.The organic matter maturity of the lower source rocks is higher,and the organic matter abundance and type are better.The source rocks in the upper part of the Xinancun Wuyun formation in Fangzheng fault depression are widely distributed in the whole basin,with a distribution area of1077.68km²,of which the mudstone in deshantun depression is the most developed,with a thickness of more than 400m and a maximum thickness of 800m;the distribution of shale source rocks in the lower part of the Xinancun Wuyun formation in Fangzheng fault depression is relatively limited,mainly in the north of the fault depression,with a distribution area It reaches 823.27km²,of which the mudstone in Xingwang structural belt is the most developed with the maximum thickness of450m,and the mudstone thickness gradually thins to the south.2.In terms of organic matter abundance,the organic matter abundance?TOC?of the upper source rock is 1.4%on average,and that of the lower source rock is5.10%.In terms of organic matter types,the organic matter types of the upper source rock are mainly type II2,part of type II1 and type III;the organic matter types of the lower source rock are type II1 and type II2;in terms of organic matter thermal evolution On the one hand,most of the source rocks at the bottom of Xinancun'Wuyun formation distributed along the fault depression strip are mature;only when the buried depth of Fangzheng fault depression is more than 4000m,the source rocks enter the mature evolution stage,which is the peak of hydrocarbon generation and expulsion and the main reservoir forming stage at the end of Oligocene.3.The source rock of Xinancun Wuyun formation in Fangzheng fault depression has a total oil generating capacity of 28.51×10⁸t,a total gas generating capacity of4.52×10¹¹m³.According to analogy of scale area,the value of oil migration and accumulation coefficient of Fangzheng fault depression is 7%,the value of gas migration and accumulation coefficient is 7%,the total oil resource of Xinancun Wuyun formation in Fangzheng fault depression is 2.00×10⁸t,and the total resource of natural gas is 316.4×10⁸m³.4.The oil and gas resources of Xinancun Wuyun formation in Fangzheng fault depression are calculated by evaluation units.The results show that the oil and gas resources are mainly concentrated in Xingwang structural belt,Dalinzi depression belt,Deshantun depression belt and Lijiadian depression belt.