| The Shanjianfang area is a potential oil and gas exploration area in the eastern margin of xiaocaohu sub-depression in Turpan-Hami Basin.Due to the low level of exploration,there are few studies on the development of source rocks in the study area,and the characteristics,distribution and development of source rocks are uncertain.The analysis of source,reservoir and cap assemblage in the study area is relatively relatively,and the research on reservoir forming conditions and laws is lacking.Due to the shortcomings mentioned above,further oil and gas exploration and prediction of favorable areas in Shisanjianfang area are hindered.In this paper,after summarizing previous research schemes of reservoir forming conditions and methods of predicting favorable areas for exploration,combined with the source rock analysis and core reservoir physical property data of Shanjianfang,the development characteristics of reservoir forming geological conditions in this area are systematically analyzed by basin simulation technology using δ LogR technology.The research focuses on the evaluation of coal measure source rocks,the analysis of hydrocarbon generation capacity and the restoration of hydrocarbon generation history,and the analysis of middle Jurassic reservoir and Jurassic reservoir cap.On this basis,the mechanism of oil and gas accumulation and the cause of drilling failure in the study area are summarized,and the potential exploration favorable areas in the study area are predicted.The results show that the Jurassic strata in Shisanjianfang are thick in the south and thin in the north.The lithology of source rocks in Shuixigou Group is mainly dark and carbonaceous mudstone and coal rock.The abundance of dark and carbonaceous mudstone and coal organic matter in Shuixigou Group is medium to very good,medium to poor,respectively.The organic matter types of mudstone and coal are ii2-iii and iii,respectively.The Ro range of Xishanyao formation and Badaowan Formation is 0.61.2%and 0.6-1.4%,respectively.δ LogR technology predicts TOC,indicating that the abundance of organic matter in Xishanyao Formation is higher than that in Badaowan that in Badaowan Formation,which is consistent with the measured value.From south to north,xishanyao formation and badaowan formation have braided river delta plain,front and shore and shallow lake,so the high quality source rocks of shore and shallow lake facies are relatively developed in the north.The high quality mudstone ranges from 100 to 300m and 50 to 200m,and the coal ranges from 20 to 60m and 10 to 80m,respectively.The hydrocarbon generation intensity ranges from 5 to 55×108kg/Km2 and from 5 to 25×108kg/Km2 respectively.The hydrocarbon generation intensity is controlled by the thermal evolution degree and thickness of source rocks.The middle Jurassic reservoir lithology is mainly composed of feldspar lithic sandstone,and the reservoir physical properties reach the density standard.Sanjianfang Formation is better than Qiketai and Xishanyao formation,and the cap rocks are developed in the northwest of the pier.There are multiple sets of source-reservoir-cap assemblages.Shuixigou group is the source rock and sanjianfang is the reservoir,and the upper part of the sanjianfang is the cap rock.The study area is the first stage of hydrocarbon generation,and the fluid inclusions show two stages of filling,namely late Jurassic-early Cretaceous and Paleogene,Xishanyao formation is the main hydrocarbon-generating layer,followed by Badaowan formation,and one favorable exploration area of type Ⅰ and type Ⅱ is predicted. |
