The Key Geological Factors And Exploration Potential Evaluation Of Shale Gas Enrichment For Nanhua System In Guizhou And Chongqing Area

Through the study of gas-rich South China shales key geological factors, thepreliminary evaluation of the key geological factors Nanhua System shale gasenrichment, provide a basis for the Sichuan Basin and the surrounding areas of shalegas exploration.The region Datangpo widely distributed, mainly in the study area Xiushan-Songtao Datangpo lower part of the study area, the overall is a black carbonaceousslate or shale, slate black manganese thickness0-200m, the upper part is grayishgreen silty slate, thickness0-500m, up to a maximum thickness of shale evaluationarea600m, shale type Ⅰ main types of organic matter, mainly composed by thesuspected source of the algae.Original organic carbon content and more concentrated in0.45-1.25%of theoriginal organic carbon content exceeding10%in some areas; are good source rocks;organic matter has reached maturity (generally RO>5.5%) stage.Brittle shale minerals quartz content of38%-46%, the clay mineral compositionof60%-80%, mainly illite and chlorite, is conducive to fracturing.Average porosity shale is5.051%, the average penetration rate of about0.010md. Fractured shale, the main tension cracks were filled with calcite.In this paper, two samples were selected in the study area thousands of sub-gateregion Q-2and Q-3were isothermal adsorption experiments, each sample of eachexperiment done30℃and50℃under Experimental results show that theadsorption isotherm, the adsorption capacity and inversely proportional totemperature, pressure and proportional to the concentration of organic carbon.According to domestic and international standards will evaluate alternativestudy area is divided into five zones, the shale gas resource estimates for eachcandidate area. Use of resource abundance analogy, based on five parameters area ofshale gas weighting coefficient table, shale gas resource abundance table has fivealternative area, find their own resources, and then accumulate draw Datang studyarea shale gas resource estimates set the value of the slope is about1.4trillion m3.