云南曲靖地区下寒武统筇竹寺组页岩气成藏地质条件及有利区预测

基于野外地质调查、岩心观测、地球化学分析、含气量现场解吸等技术手段,深入分析了云南曲靖地区下寒武统筇竹寺组页岩气形成与富集条件。研究认为该区筇竹寺组沉积期为浅水陆棚环境,黑色泥页岩厚度237~363 m,成熟度较高,平均R_o为3.06%,TOC多数大于2.0%;页岩中石英含量平均为53.18%,碳酸盐矿物含量平均为18.82%,储集空间以泥页岩微裂缝、粒间孔、粒内孔和有机孔为主;区域具有较好的页岩气勘探潜力。根据多口钻井现场解吸气量较低的特征,推断保存条件是曲靖地区页岩气富集的关键,马龙为页岩气勘探远景区。

Geological Conditions for Shale Gas Accumulation and Favorable Area Prediction in Qujing of Eastern Yunnan

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.