鄂尔多斯盆地中部延长组长6段低阻油层成因机理与测井识别

Genetic mechanism and logging identification of low resistivity oil reservoir in Chang 6 member of Yanchang Formation,Ordos Basin

鄂尔多斯盆地延长组低电阻率油层成因机理分析和测井识别一直是研究的难点问题,探索延长组低电阻率油层成因机理、分析主控因素、形成针对性的测井识别方法十分必要.为此,在文献系统调研基础上,结合已有研究成果,结果表明:(1)储层孔隙结构、束缚水饱和度、黏土矿物附加导电是低电阻率油层形成重要原因;(2)成藏动力条件与储层的配置关系直接影响储层含油饱和度,进而影响储层电阻率值,源储配置关系分析在低电阻率油层识别中必不可少;(3)在常规测井参数定性识别,根据试油试产结果,确定低电阻率油层的常规测井响应特征,通过交会图技术、可动水分析技术,实现了储层流体定性识别;定量评价中,W-S模型计算结果与实际分析结果吻合度最高,适用于研究区长6段低电阻率油层饱和度计算.

The genetic mechanism analysis and logging identification of low resistivity oil reservoirs in Yanchang Formation of Ordos Basin have always been difficult problems.It is necessary to explore the genetic mechanism of low resistivity oil reservoirs in Yanchang Formation,analyze the main controlling factors and form an effective logging identification method.Therefore,on the basis of systematic literature survey and combined with research results,the research shows that:(1)reservoir pore structure,bound water saturation,additional conductive clay minerals and conductive rock minerals are one of the important reasons for the formation of low resistivity oil reservoirs;(2)The relationship between accumulation dynamic conditions and reservoir configuration directly affects the oil saturation of the reservoir,and then affects the resistivity of the reservoir.The analysis of source-reservoir configuration relationship is essential in the identification of low resistivity reservoirs.(3)In the qualitative identification of conventional logging parameters,according to the results of oil test and production test,the conventional logging response characteristics of low-resistivity reservoirs are determined.The qualitative identification of reservoir fluids is realized by crossplot technology and movable water analysis technology.In the quantitative evaluation,the calculation results of W-S model is in good agreement with the actual analysis results,which is suitable for the calculation of the saturation of the Chang 6 low resistivity reservoir in the study area.