N₂ Foam Flooding Technology Research For A Bohai Oilfield Target Reservoir

In this paper,according to the development characteristics of Bohai sea target reservoir,especially,strong heterogeneity and the great difference between high and low residual,the combination of numerical simulation and physical simulation experiment method had been adopted to evaluate the adaptability of nitrogen foam flooding in the target block,providing technical ideas and reference for the development of similar reservoir.According to the target block reservoir conditions,an appropriate foam system had been selected.Then a series of nitrogen compound water flooding experiment had been carried out under the geological conditions of the target block.The study found that the oil displacement efficiency in the order from low to high is nitrogen flooding,water flooding,nitrogen alternating water flooding,nitrogen foam flooding,polymer slug plus nitrogen foam flooding.The last production development schedule improves the low permeability layer recovery degree,and the comprehensive recovery efficiency reached 69.16%.Then,the numerical simulation test is carried out by use of GMC software.Four parameters,the size of preconditions polymer slug and main slug,the polymer concentration,and injection pattern are optimized.Finally got the optimum nitrogen foam displacement development plan,which provides some guidance for the target block field development.