涪陵焦石坝地区五峰组-龙马溪组含气页岩岩相划分——以JY11-4井为例

Lithofacies Classification of Gas Bearing Shale in Wufeng-Longmaxi Formation:A Case Study of JY11-4 Well

针对目前焦石坝地区海相页岩气勘探开发需要,以JY11-4井岩心资料为基础,通过电子显微镜观察、矿物组分及有机碳含量分析,研究区五峰组-龙马溪组页岩矿物组分以石英和粘土矿物成分为主,含有长石、方解石、白云石、黄铁矿等,有机碳含量0.55%~5.89%,具有自上而下逐渐增加趋势,结合U、TH测井解释结果,剖析五峰组-龙马溪组页岩岩相特征,划分为低有机质贫硅页岩相、中等有机质贫硅页岩相、低有机质富硅页岩相、中等有机质富硅页岩相和富有机质富硅页岩相等5种岩相,其中富有机质富硅页岩相为页岩气勘探开发最有利页岩相,对南方海相页岩气的勘探开发具有重要指导作用。

Based on corestone data of JY11-4Well in Jiaoshiba area and the analysis of its mineral component and organic carbon content,it is believed that quartz and clay mineral are major mineral components of the shale in Wufeng-Longmaxi Formation,accompanied with feldspar,calcite,dolomite and iron pyrite,and organic carbon content is0.55%~5.89%from top to bottom.By analyzing the shale phase of Wufeng-Longmaxi Formation combined with results of U and TH well logging interpretation,five phases are determined：low-organic and low-silicon shale phase,medium-organic and low-silicon shale phase,low-organic and high-silicon shale phase,medium-organic and high-silicon shale phase,and high-organic and high-silicon shale phase,among which the last is the most suitable to exploration and development of shale gas.