| Based on the field research, core observation, geochemical analysis and gas desorption analysis, the shale gas enrichment conditions were studied and discussed in Qiongzhusi Formation of the lower Cambrian in Qujing area of Eastern Yunnan. It is shown that the thickness of black shale in Qiongzhusi Formation is 237~363m, the TOC values varied in a wide range with the majority of them higher than 2.0%, the average of maturity(Ro) is 3.06%, the average of quartz content is 53.18%, and the carbonate mineral content averaged 18.82%. The primary pore space are microcracks in mud shales, intergranular pores, intragranular pores and organic pores. The comprehensive analysis showed that the study area has a good potential for shale gas exploration. In addition, according to the lower gas desorption from several wells in the field, it can be deduced that the key for the enrichment of shale gas is preservation conditions in East Yunnan, and the Malong area could be the target for shale gas exploration. |
