The Research Of Numerical Simulation For Polymer Flooding In Class Ⅲ Reservoir In Beierdong Block

The current recovery percent has reached 40.28% in Sabei oil field, and the Class I reservoir has a higher degree of development after polymer flooding, but Class II and III reservoirs mainly with water flooding, particularly the Class III reservoir, still have a lot of residual oil left in the underground, which are the potential for further increasing reserves and production. The combination of Class II and III reservoirs test has been launched since 2004, which explored the economic feasibility of chemical flooding in Class III reservoir through well pattern thickening and tertiary oil recovery. The result showed that the reservoirs of more than 0.5m could got better effect of increasing oil production through polymer flooding, but the reservoirs of less than 0.5m and useless reservoirs were in poor condition and had serious interference among layers.In the paper, the geological deposition feature, heterogeneity, flooding conditions and degree of reservoir use of reservoirs were analyzed. According to the dynamic and static characteristics, the fine geological model was established by using the Petrel software, which the permeability, porosity and effective thickness were calculated by using the phased interpolation. The water flooding history matching of the reservoirs was carried out, and the result had higher degree of conformity and met the precision request. Then, the distribution of residual oil saturation was predicted and the genetic type of distribution and major influencing factors of remaining oil was analyzed. This paper has also optimized injection parameters of polymer solution including injection rate, concentration and volume, which were 1000, 1200mg/L, 0.15 PV/a, 0.64PV and 800, 1000mg/L, 0.15 PV/a, 0.64PV seperately, and designed the development programs, then evaluated the effects to get the best development plan, and finally verified the economic viability of the program by economic indicators evaluation that the internal rate of return of 17.79% was more than the industry standard of 12%.The injection parameters of polymer solution and development programs were optimized in this paper which can provide a theoretical basis for the rational development of the block. It has an important significance for improving the potential capacity and the development effect of Class III reservoir in the north-two-east eastern block.