Assessment Of Resource Potential And Area-Selection Concerning Shale Gas Of Longmaxi Formation In Pengshui-Nanchuan Area

Shale gas is a kind of non-conventional natural gas and shale gas exploration and development work is in full swing in China.China's oil and gas exploration areas is becoming more and more extensively,and foreign exploration and development of shale gas theory and technology mature.In this paper,evaluation of shale gas resources in Longmaxi Formation of Lower Silurian developed in Pengshui-Nanchuan Area is a combination of regional tectonic and depositional setting,results of previous studies,well logging,under the guidance of the basic theory of the sedimentology and petroleum geology for the research of the following five aspects:(1)As tectonic events are complex in the process of basin evolution,the tectonic actions in the Pengshui-Nanchuan area are partition style folded belt and trough like folded belt.Deep muddy shelf is the major sedimentary environment for the formation of hydrocarbon source rock,while Pengshui-Nanchuan area is deep muddy shelf,.(2)Organic geochemical studies show that Silurian Longmaxi Formation in Pengshui-Nanchuan area features high organic content(TOC:1.0%-5.0%).The organic matter is over mature with Ro:2.0%-3.0%and dominated by type ?-kerogen.(3)The characteristics of reservoir,fracture and pore of shale were studied,showing that Silurian Longmaxi Formation in the study area features high brittle mineral content(more than 52%-85%),poor physical properties(porosity:2%-3%;permeability:0.05-0.01mD)and multiple types of micro fractures(size:0-4?m,average plane porosity:2.27%).(4)Study the relationship between shale gas adsorption content and the TOC.temperature simulation experimental study showed that:at the same temperature,the mud shale of Pengshui-Renhuai Area margin adsorption test of gram size and sample's TOC obvious being related to sexual.Through statistical analysis of experiments,measured the shale adsorbed gas content of Pengshui-Nanchuan Area margin and the TOC,established the quantitative relationship.(5)Preliminary estimation with the volumetric method shows that shale gas volume in Pengshui-Nanchuan Area was 13243.8×108m3.Initially identified the Pengshui-Nanchuan Area has one prospect area,three favorable areas,four target areas.