摘要
低电阻率油气层的测井响应特征不明显，其电阻率数值很低，有时比围岩的电阻率还低。油层被误解释或漏掉的情况时有发生。分析了曲堤油田沙三、沙四段低电阻率油气层的岩性、物性、含油性及电性特征，认为低电阻率的成因是：束缚水含量高；伊利石粘土吸附水，使总束缚水含量增加；地层水矿化度偏高；亲水岩石表面形成水膜，成为导电通道等。介绍了定性评价方法。在定量解释中，用Ｓ－Ｂ新模型计算含水饱和度，用曲１０井的实际资料验证认为此模型比阿尔奇公式好。
Log response features of reservoirs with low resistivity are not obvious. The resistivity values of such reservoirs are quite low and sometimes are lower than the resistivity of their surrounding rock. Cases that being misinterpreted or missed out often occur. Based on the analyses of lithology, physical characteristics, oil bearing status and electric behavior of low resistivity reservoirs of the third and the fourth sections of Shahejie formation of Quti oilfield, it is considered that the origin of low resistivity is that there is a large quantity of irreducible water in the formation; illite and clay imbibe water to make the total irreducible water increase; the salinity of formation water is higher; there is water film on the surface of water wet rock which becomes conductive passages. This paper presents some qualitative evaluation methods, new model S B to calculate water saturation has been used and actual data of well Qu 10 verify that this model is better than Archie formula.
关键词
低电阻率
油气层
测井解释
油田
low resistivity, reservoir, origin, log interpretation
