四川盆地焦石坝地区龙马溪组泥页岩储层测井识别  

Logging identification for the Longmaxi mud shale reservoir in the Jiaoshiba area,Sichuan Basin

作　　者：严伟[1] 王建波[1] 刘帅[1] 王昆[1] 周依南 

机构地区：[1]中国石化勘探南方分公司勘探研究院

出　　处：《天然气工业》2014年第6期30-36,共7页Natural Gas Industry

基　　金：国家科技重大专项"上扬子及滇黔桂区页岩气资源调查评价与选区"(编号:14B12XQ151001)

摘　　要：与常规气藏相比，页岩气藏具有弱敏感地球物理参数特征，这就大大增加了地球物理测井技术识别页岩气储层的难度。为此，对四川盆地焦石坝地区下志留统龙马溪组海相页岩气井的测井曲线进行了对比分析，总结出泥页岩在常规测井曲线上具有高自然伽马、高铀、低钍、低钾、相对高电阻率、高声波时差、低中子、低密度、低光电吸收截面指数的特征；在元素测井资料上表现为硅含量增加，铝含量和铁含量降低。以泥页岩测井响应特征为基础，优选对泥页岩最为敏感的自然伽马测井曲线、中子测井曲线、密度测井曲线，将上述曲线进行叠合能较好地识别泥页岩，有效区分富有机质泥页岩和非富有机质泥页岩。在定性识别的基础上，密度测井值能较好识别非富有机质泥页岩和富有机质泥页岩，前者密度测井值介于2．61～2．70g／cm^3，后者小于2．61g／cm^3。采用上述测井识别方法得到的结果与现场含气量测试、实验实分析有机碳含量和气测录井结果有着较好的一致性，可以为该区页岩气测井参数计算提供依据。Compared to a conventional gas reservoir, a shale gas play presents weak sensitivity to the logging data reflecting petro physical properties so the previous petrophysical logging technology is becoming increasingly difficult to identify a shale gas play. Therefore, through a comparative analysis of logging curves of gas wells in the Lower Silurian Longmaxi marine shale gas play in the Jiaoshiba area, Sichuan Basin, we concluded that mud shales on conventional log curves are generally featured by high gamma ray, high uranium, low thorium, low kalium, relative high resistance, high acoustic wave, low neutron, low density and low of photoe lectric absorption cross section index, while on elements logging data they are featured by the increasing of silicon content and the de creasing of aluminum and iron contents. Based on the logging response characteristics of mud shales, the most sensitive logging curves of the shale gamma ray, neutron and density logging were optimized and then coincided to identify the mud shales very well, and even to tell the difference between the organic rich and organic poor mud shales. On the basis of qualitative identification, the density logging values can identify the mud shales with rich organic matters with 2.61 2.70 g/cm^3 and those with poor organic matters with less than 2.61 g/cm^3. As a result, the identification results agree well with field tests of gas content, experimental anal ysis of organic carbon content, and the practical gas logging so this study provides reference for the interpretation of logging parame ters.

关 键 词：四川盆地 焦石坝地区 志留纪 泥页岩 页岩气 测井响应 储集层识别 叠合法 交会法 

分 类 号：P631.81[天文地球—地质矿产勘探] P618.13[天文地球—地质学]