在S 区块发现了一批低电阻率油层（电阻率最低达1.7 Ω·m），与水层电阻率相当，用常规测井解释方法识别油水层极为困难。以岩心扫描电镜、黏土矿物分析、毛管压力、地层水分析资料为基础，对S区块低电阻率油层成因机理进行了综合分析，认为该区油层低电阻率的主要成因是高矿化度地层水和低含油饱和度。针对不同成因的低电阻率油层，提出了视地层水电阻率与可动流体分析相结合的低电阻率油层评价方法。通过该区36 口井实际资料的处理，其应用效果较好。

Agreat deal of lowresistivity reservoirs are discovered in block S. The lowest resistivity of the reservoir is only 1.7Ω·m, corresponding to the resistivity ofwater layer, which makes it extremely difficult to recognize the property of the fluid. Based on scanning electronic microscope, claymineral analysis, capillary pressure and formation water property, the genetic mechanism of the lowresistivity in block S is analyzed. It is believed that the lowresistivity is mainly caused by highly mineralized formation brines and lowoil saturation. An evaluation method for lowresistivity reservoirs of different genesis is proposed, which combines apparent formation water resistivity and movable fluid analysis. The actual processing data of 36 wells prove the good result.