焦石坝龙马溪组高效页岩气单元录井划分及评价探讨

Division and Evaluation of Shale Gas Unit Log of Longmaxi Formation in Jiaoshiba

四川盆地常规和非常规天然气资源丰富，盆地内志留系龙马溪组公认为一套优质烃源岩。近年来，随着勘探实践的深入，在涪陵焦石坝工区发现龙马溪组底部暗色泥页岩发育，自身具有一定的页岩气特征，且录井显示较明显。通过对该区典型井A井页岩气显示研究后，应用录井手段划分出由上隔板区、下隔板区及核心区组成的页岩气基本单元，特征与美国Eagle Ford页岩气单元相似。通过录井评价认为，该井2341．0-2415．5 m页岩气核心区为优质页岩气层，储层流体为干气，地层具有高压特征，上、下隔板密闭性强，多元数据对比分析关键成藏条件远好于邻区的侏罗系大安寨段及东岳庙段页岩，具有获得页岩气工业产能的地质基础。

Sichuan Basin is rich in conventional and unconventional natural gas .Longmaxi Formation in it is recog‐nized as a set of high-quality source rocks .In recent years ,further exploration in Fuling Jiaoshiba work zone has found that dark shale is well-developed at the bottom of Longmaxi Formation with an obvious logging presentation that the dark shale itself contains some shale gas .Based on the research and logging evaluation of shale gas show of typical A well in Jiaoshiba work zone ,the author holds that high-quality shale gas layer lies in the core area of A well from 2341 .0 m to 2415 .5 m .formation fluid is dry gas .The layer＆#39;s pressure is high and upper and lower inner covers have strong leakproofness .Multi-data comparative analysis shows that the key reservoir forming conditions in the core area are far better than adjacent Jurassic Daanzhai Member and Dongyuemiao Member ,having geology foundation for gaining shale gas industrial capacity .