The Research On The Chemical Displacement Improving Development Efficiency In Niuxintuo In Liaohe Oilfield

Based on the geologic feature and the problems faced in water flooding in Niuxintuo Oilfield, we had done the research on displacement efficiency of different flooding systems through indoor physical modeling experiments.We had selected the proper molecular weight and concentration of polymer through experiments, and the results showed that 970×10~4 of molecular weight and the concentration between 500-1500mg/L was matched well with the cores of 100mD, while 500×10~4 of molecular weight was matched well with the cores of 50mD. Selected surfactants formed ultra-low interfacial tension, the range from 0.2% to 0.4%, the compound systems with HLX surfactant and polymer could not form the ultra-low interfacial tension with oil, even without surfactant. While B kind surfactant system and it with polymer compound system could form the ultra-low interfacial tension between 55℃and 70℃.In the paper, we had particularly done the research on influences of polymer flooding and binary compound flooding on the displacement efficiency in artificial cores with various fracture length and coefficient of variation and based on which evaluated the influence of profile control agent on the displacement efficiency.The results showed that the chemical recovery and total recovery of two flooding systems increased as the fracture length increased. The chemical recovery increased as coefficient of variation ranged from 0.6 to 0.85, while total recovery discreased. Adding the profile control agent systems can enhance more recovery than that without it under the same condition. In total, the experiments carried on the heterogeneous cores showed that polymer-surfactant system had better displacement efficiency than polymer did, while the surfactant is the worst.