Shale Gas Accumulation Characteristics And Resource Potential Of Jurassic In The Northern Margin,Qaidam Basin

Shale gas is occurrence in mud shale gas, give priority to with adsorption or free state exists, show the typical "in situ" accumulation mode, belong to the category of unconventional gas resources. Shale is the source rock of gas generated and gather and save gas reservoir and cap rock. Our country is rich in shale gas resources, species diversity, a preliminary estimate, shale gas resources around 100 trillion Cubic meters. In recent years,our country shale gas exploration investment increasing, shale gas reservoiring theory constantly improve, especially in Chongqing Fuling district, the shale gas productivity of 5 billion cube is completed, marked our country business development stage of shale gas.Northern Qaidam Basin is the most important coal-bearing basin in Qinghai province,the mudstone formation development large thickness of Jurassic is rich in organic matter,organic matter maturity, good shale gas geological conditions. System was studied for the Qaidam shale gas geological conditions, estimate its resources, to further the deployment of the shale gas exploration and development work, has good guidance meaning. To adjust the energy structure of Qinghai province and alleviate the pressure of the energy will play a positive role. Based on shale gas resources strategic research in Qinghai province and district projects as the backing, in Qaidam area Jurassic strata based on regional geological background, rich organic matter dark mud shale analysis of Jurassic hydrocarbon generation conditions and reservoir conditions and the characteristics of hydrocarbon resource estimates and favorable exploration area.Think between the delta plain distributary bay and delta front, lakeside, shallow lake,half deep lake environment are favorable for the formation of the shale. A large number of drilling and seismic data show that Qaidam Lenghu area of mud shale thickness is more than 1000m, soft shelled turtle mountain, fish, big coal ditch, mudstone thickness of up to 100m-good hydrocarbon source rocks. Through reservoir brittle mineral characteristics, 'high silica,clay, high low carbonate' characteristics, reservoir space types, gas shows obvious, good condition of shale gas development.Through the volume method, quantity of shale gas source for the estimate. TOC correlation method is used to collect the Jurassic gas content of the shale in the study area.The calculation in Qaidam basin, the Jurassic shale gas geology resources of 9817.6 billion square, combined with the thickness of mudstone, mudstone in the burial depth of the strata,organic carbon content, such as thermal evolution degree, the surface condition advantageous area selection criteria, select the Qaidam Lenghu No.3&4, Yuqia, Tuanyushan, Dameigou,Lvcaoshan, Dayangtou as shale gas prospective areas for shale gas exploration.