Research On The Remaining Oil Distribution And Description After Polymer Flooding

In Daqing oilfield, several polymer flooding blocks developing the PI main pay zone have entered the late polymer flooding period or even the following water flooding period. Although the recovery of polymer flooding can be up to 60%, still 40% of the reserves need to be dug further, which is very important to the sustaining development of Daqing oilfield. This paper concluded the features of the remaining oil distribution after polymer flooding and supply different methods to dig different types of remaining oil. By measuring the untouchable pore volume and massive flat physical simulation, researching the remaining oil distribution features and influence factors, analyzing and describing the types of remaining oil, calculating the reserve ratios of the different water flushed segments and deposition units, this paper draw a conclusion that the remaining oil mainly lies in the middle-high permeability segments, especially in the PI2 and PI3 deposition units with developed fluvial sandstones. So the main target is increasing the sweep efficiency of medium water flushed segments. This paper established theφfunction to predict the remaining oil saturation after polymer flooding and compiled the fast numerical simulation program, realized the prediction of several polymer flooding indications.