Sedimentary Sequence And Paleoenvironmental Characteristics Of Enriched Organic Matter Shale In Wufeng-Longmaxi Formation,Eastern Chongqing

China has abundant oil and gas resources.In addition to conventional oil and gas resources,unconventional shale gas also has a good prospect for exploration.This paper five mountains in eastern chongqing area-the dragon stream shale as the research object,the group of rich organic matter in sedimentology,geochemistry,reservoir geology,such as under the guidance of the theory,through the comprehensive utilization of the research in the field profile data and drilling core data,combined with the test and analysis data statistics,studies the rich organic shale lithology characteristics,through the research of sedimentary sequence,further analyzing five mountains in eastern chongqing-the dragon stream group of rich organic matter the paleoenvironment evolution of shale,the final analysis the rich organic matter of shale oil and gas geological significance.Through microscopic thin section observation and description,geochemical data processing and analysis,the rock types,sedimentary structure,biological combination,and identification of sedimentary facies marks,on the basis of the late ordovician to early silurian in the studied area five mountains-creek group of shale has carried on the classification of sedimentary facies,the dragon can be mainly classified as shelf and platform facies,and according to the water depth and shelf facies lithology can further be divided into shallow water shelf,deep-water shelf subfacies,siliceous carbonaceous mass shelf,contain arenaceous shale shelf,calcium carbon shelf,such as carbon shelf sedimentary microfacies.The sedimentary facies types and spatial distribution rules of the wufeng-longmaxi formation in this period were discussed.According to the characteristics of rock and mineral content in the study area and the characteristics of the combined use of trace element ratio method,a constant element ratio method and other methods,in-depth analysis of rich organic matter shale formation ancient environmental characteristic,this text-the dragon stream group of rich organic matter shale mainly Marine deposits formed in the cold environment,the study area are mainly composed of continental shelf facies,most from terrigenous clastic sedimentary matter,affected by the global geological events in the process of rock formation,there are some different period of organic matter productivity change,but the overall belongs to the high organic matter production conditions.According to the result of scanning electron microscopy(sem),eastern chongqing area five mountains-the dragon stream group of rich organic matter shale bore shale porosity is mainly composed of organic matter,minerals(including: intergranular pore and intergranular/in/within the pore and dissolution pore,etc.),and the composition of microfracture,pore related data analysis it is concluded that the lower part of the dragon stream with good reservoir space,thus proving the dragon stream in the study area group of lower organic shale interval is good shale gas enrichment.