Assessment Of Resource Potential And Area-selection Concerning Shale Gas In Bayanhaote Basin

As an unconventional resources developing rapidly these years,shale gas has proved its fantastic prospect.Based on the data of outcrop and geochemistry data,this research is aimed at the Carboniferous shale in central and southern margin of Bayanhaote Basin,including the distribution features of target shale,the geochemistry properties of organism and the shale reservoir features.In the end,the shale resources potential is calculated as well as the shale area-selection is made.The Bayanhaote Basin suffered a large-scale transgression in Carboniferous and the transitional sediments were deposited.The sedimentary pattern which featured"delta in north while barrier island-lagoon in south" is beneficial for the shale development.The target shale layer is mainly located at the Jingyuan Formation,Yanghugou Formation and the Taiyuan Formation in the Upper and Middle Carboniferous.The ratio of thickness of shale and total stratigraphy is generally high(>40%).On the other hand,the areas of relatively thicker shale are Wuda area in the northeastern margin,Dashitoujinggou area in the southern margin and Bacan 2-Bacan3 area in central depressdion.The depth of the former two is less than 1000m while the top surface of latter one is 2500m-3400m.In the end,six shale series are selected from the diagram of stratigraphic correlation,which comes from the outcrop profile.The classifications of organic matter are type ? and type ?,the former one mainly lies in the central basin,while the latter one commonly occurs in the transitional facies of eastern and southern margin.Besides,as the key standard in assessing resources potential,TOC varies between 1%and 5%.Last but not least,the vitrinite reflectance data shows that the organic matter is generally in mature-post mature phase.The shale in target basin can be devided into siliceous-lamination-containing black shale,blocklike mudstone,silty blocklike mudstone and mica-containing grey-black shale.The fragile mineral(quartz)takes account for 20%or so on average,while the proportion of carbonate mineral is pretty small.The abosorbed gas content coming from the experiment of isothermal adsorption is 4.34 m3/t,which is higher than that in Erdos basin.Based on the key parameters such as the thickness,area and absorbed gas content etc.,we can work out that the resources potential is 417.16×108m3 with the application of volume method according to the "the assessment of shale gas resources potential and the standard of area-selection" made by the Ministry of Land and Resources.Then one type ? profitable area(Bacan 2-Bacan 3)and two type ?profitable areas(to the north of Wuda and Hongshuibao-Yingpanshui-Dashitoujinggou)are picked out.