为了认识黏土矿物对油层低电阻率化的影响，以薄片、扫描电镜、X 射线衍射、测井解释和试油结果 为依据，对吴起地区长6₁油层黏土矿物特征及其对电阻率的影响进行了研究。结果表明，黏土矿物对低 电阻率油层的形成具有控制作用，具体表现在3 个方面：第一为附加导电作用，以网状伊/蒙混层矿物最 强，是油层电阻率降低的关键因素；第二为对孔隙结构的改造，导致束缚水饱和度增高，电阻率降低，以伊 利石最为明显；第三是对水分子的吸附作用，以绿泥石等为主。综合三者的作用大小和矿物含量，吴起地 区黏土矿物对电阻率的影响程度依次为：伊利石>伊/蒙混层>绿泥石>高岭石。此项研究可对低电阻率油 层的存在机理和分布进行有效解释和预测。

In order to understand the effect of clayminerals on lowresistivity reservoirs, the slice, scanning electronic microscope, X-ray diffraction, logging interpretation and oil testing results were applied to study the effect of clay minerals on resistivity of Chang 61 reservoir in Wuqi area. The result shows that clay minerals play a dominate role on the forming of low resistivity reservoir. The role displays in the following three aspects: the role mainly is additional conductivity, and it is strongest in the illite/smectite mixed layer and is the key factor for resistivity decline; followed by the pore structure reformation which caused the bound water saturation increasing and resistivity decline, and it is most in illite; and then the absorption of water molecule which is mainly in chlorite. By considering the effects and mineral content, it was believed that the order of effect of clay minerals on resistivity is: illite > illite/semectite mixed layer > chlorite > kaolinite. This study result can be used to interpret the mechanism and predict the distribution of low resistivity reservoir.