威远地区筇竹寺组页岩气成藏条件分析

Shale gas reservoir-forming conditions and predicting favorable exploration area in Qiongzhusi formation,Vying region

利用威远地区筇竹寺组黑色页岩野外露头剖面实测资料及钻井岩心样品分析化验结果,从富有机质页岩的沉积展布特征、地球化学特征、岩石物性特征及页岩气保存条件等方面对川南威远地区下寒武统筇竹寺组页岩气的形成条件进行分析。结果表明:研究区筇竹寺组页岩沉积厚度较大,为200 m^300 m;有机质丰度高,平均为2.15%,成熟度较高,达到过成熟阶段,有机质类型以Ⅰ型为主,Ⅱ_1为辅;页岩中脆性矿物含量较高,以石英长石为主,黏土矿物含量中等,以伊利石为主,有利于页岩气的形成与富集。

According to the measured profile of dark shale and the laboratory test results of rock samples, this paper studies the regional distribution, geochemical and reservoir characteristics and conservation conditions of shale gas to reveal the shale gas generation. Results show that the shale gas in lower Cambrian, Vying region, southern Sichuan basin, with large sedimentary thickness, up to 200 m-300 m, mainly as deep continental shelf sediments, organic matter abundance of shale is high, the average is 2.15 %, maturity is higher, reaching high mature stage, organic matter type is given priority to type I, Ⅱ1is complementary, brittle content of minerals in shale is high,dominated by quartz, content of clay is medium, dominated by illite, which is in favor of the generation and accumulation of shale gas.