The Characteristics Of Cenozoic Fault System In The Eastern Bonan And Its Control On Sedimentation

The Xijiang Sag is located in the Zhuyi Depression of the Pearl River Mouth Basin,and is composed of the east,west,south,and north half-grass valleys and the mid-low uplift.Uplift zone.At present,the sag exploration in Chengdu is low,and there is a lack of work on the distribution characteristics and hydrocarbon generation potential of the source rocks in the Wenchang-Enping Formation.In this paper,the Wenchang-Enping Formation source rocks formed in different sedimentary environments are taken as the research object,based on drilling data,organic carbon data and rock pyrolysis data,combined with organic geochemical analysis,sedimentary facies analysis,basin simulation analysis Methods The organic matter abundance,organic matter type,organic matter maturity,development characteristics,vertical distribution law and hydrocarbon generation potential of Wenchang-Enping Formation source rocks in Zhongxijiang Sag,Zhuyi Depression were studied.And made the following conclusions:The oil generation threshold of the source rock in Xijiang Sag is about 3000 m,3000m-4000 m is in the low-maturity stage,and it is in the mature stage below 4000 m.The source rocks of the Wenchang Formation are mainly developed in the delta plain facies,and the source rocks of the Enping Formation are mainly developed in the swamp plain,the delta plain facies and the shore-shallow lake facies;the well-developed source rocks in the SQ2-SQ4 sequence of the Wenchang Formation,SQ5-The source rocks of SQ6 sequence are poorly developed,the source rocks of Enping Formation are well developed overall,and the sequence of SQ1 is better than other sequences.The source rocks of the Wenchang Formation are mudstones with an average TOC of 0.56-0.75% and an average PG of 2.1-2.48%.The evaluation results of source rocks are poor-medium source rocks.The source rocks of Enping Formation are mudstone and coal seam,where the coal seam thickness is about 10-60 m,the average mudstone TOC is 1.07-3.44%,and the average PG is 3.24-11.02%,the source rock is better,Basically reached the level above medium.The organic matter types of source rocks in Wenchang-Enping Formation are between Type ? 1 and Type ? 2,mainly Type ? 1;the organic matter types of source rocks in Chinese Chang Formation are all Type ?1,and about half of the organic matter in Enping source rocks Humic humus type(?1)type,half of which is humus humus type(? 2)type.At present,the maturity of source rocks is at the mature stage.The vitrinite reflectance Ro of source rocks in Wenchang Formation is between 0.79-0.91%,and the vitrinite reflectance of source rocks in Enping Formation is between 0.72-0.83%.The cumulative hydrocarbon generation of the Enping group is approximately 108.3-127.3 mg / g TOC,and the hydrocarbon generation of the Wenchang group is approximately 134.3-138.7 mg/g TOC.