鄂尔多斯盆地L区块泥页岩测井识别技术

Logging Identification Technology for Mud Shale in L Block of Ordos Basin

鄂尔多斯盆地东北缘L区块存在两种类型泥页岩储层:海陆过渡相泥页岩(包括铝土质泥岩)、海相泥页岩,其对应的测井响应特征差异不明显,这制约了后续储层识别及含气性评价工作的开展。本文通过对比储层矿物组分及粘土类型的差异,分析得到泥页岩储层各测井曲线的典型特征,据此开展研究区内泥页岩识别技术研究。结论表明:常规测井、孔隙度曲线和电阻率曲线重叠法能有效识别泥页岩储层,能谱测井中伽马曲线与无铀伽马曲线在泥页岩储层处出现明显差异,常规测井组合方法根据双参数或三参数变量同时区分不同类型泥页岩。常规测井与特殊测井各有优势,开发过程中需依据区域地质情况灵活搭配测井方法以达到测井成本与储层识别准确率间的平衡。

There are two types of Mud shale reservoirs in the L block in the northeastern margin of the Ordos Basin:marine-continent transitional shale(including bauxite mud shale)and marine shale,and their corresponding logging response characteristics are different,However,it is not obvious,which restricts the development of subsequent reservoir identification and gas-bearing evaluation evaluation work.In this paper,by comparing the differences in the mineral components and clay types of the reservoir,the typical characteristics of each logging curve of the shale reservoir are analyzed and obtained,and the shale identification technology research in the study area is carried out accordingly.The conclusion show that:Conventional logging,porosity curve and resistivity curve overlap method can effectively identify shale reservoirs,and the gamma curve in energy spectrum logging is significantly different from uranium-free gamma curve in shale reservoirs.Transition facies shale,conventional logging combination method distinguishes different types of shale at the same time according to dual-parameter or three-parameter variables.Conventional logging and special logging have their own advantages.In the development process,it is necessary to flexibly match logging methods according to regional geological conditions to achieve a balance between logging cost and reservoir identification accuracy.