The distribution of remaining oil is a common concern in the later period of oilfield development，and the complexity of underground conditions makes the detection of remaining oil more difficult. The cased hole saturation logging is the most direct and effective method to detect remaining oil，which can provide strong support for the adjustment of oilfield development plans. However，one saturation logging method can hardly be applied to all geological conditions. Hence，we compared the current saturation logging methods applied in Shengli Oilfield and analyzed the characteristics of reservoirs that these methods can be applied to. According to the geological characteristics of the region，an appropriate saturation logging method was selected to evaluate the remaining oil saturation（ROS）. It can more accurately determine the channeling outside the casing，indicate the location of water leakage，and recognize the gas reservoir，the oil reservoir with low resistivity，and the oil reservoir that is injected with fresh water and produced water alternately. Additionally，this method can distinguish and analyze the fluid properties in pores near the well，determine the distribution of remaining oil，and excavate the potential oil reservoirs. As a result，the multiplicity of solutions and the influence of factors such as lithology，porosity，wellbore environment，and the salinity of formation water are reduced；the coincidence rate of interpretation results has been effectively improved. Given the result of logging interpretations，the potential reservoirs are provided for acidizing，fracturing，and perforation adding. Upon the implementation of the measures，the water cut decreases，and the oil production increases.