Shale gas reservoir characteristics and exploration potential analysis of Longtan Formation of the upper Permian Series in Qianbei Coalfield

The Longtan Formation of the upper Permian Series in Qianbei Coalfield rich in organic shale,the further research of the potential of shale gas is needed. This paper is based on the testing of mineral composition,geochemical characteristics,pore structure,rock mechanical characteristics of the well JC-1 in Qianbei Coalfield,researched the characteristic of shale gas reservoir and the potential of shale gas. The result shows that the kerogen types of mud shale in well JC-1 were all type III,The maturity of organic matter is basically 2.0%-3.0%,the value of TOC are between 0.56%-9.58%,average of 3.97%. Geochemical parameters show that the shale has a good gas generation capacity. The results of SEM scanning electron microscope showed that the micro-pores of JC-well shale mainly included intra - grain pores,intergranular pores,organic matter pores and microfractures. It provides a good reservoir for shale gas. X-ray diffraction data analysis showed that the content of brittle minerals in shale was 5.96%-87.27%,with an average value of 43.78%. The content of brittle minerals is high,so it is good for fracturing. The thickness of shales reached 48.03 m， which accounts for 36.89% of the total thickness of Longtan formation,and it has two There are two effective shale segments with continuous thickness greater than 15 m. Overall,the shale in Qianbei Coalfield has a good potential of shale gas.