Parameter Optimization And Scheme Design Of Surfactant/polymer Flooding In L90 Block

The L90 block is currently entered into high water-cut stage,with intensified plane contradictions and prominent inter layer contradictions,with significant differences in the recovery of each small layer.Due to the influence of advantageous channels,the proportion of ineffective well layers is relatively high.Currently,the well network density in the block has reached its economic limit,and it is not economically feasible to only use well pattern thickening and adjustment measures to producing remaining oil.The surfactant/polymer flooding combines the advantages of surfactant flooding and polymer flooding,and is widely used by major oil fields as an important technology for improving oil recovery in high water-cut oil reservoirs in the future.Therefore,this paper focuses on the optimization of injection parameters and project design for surfactant/polymer flooding in the L90 block.with the aim of providing technical support for further efficient mining in the block.Provide technical support for further efficient mining of this block.Based on the geological conditions of L90 block in article,a three-dimensional geological model was established.Based on geological modeling and combined with reservoir production performance data,a water drive numerical simulation model for L90block was established using CMG numerical simulation software.The distribution characteristics of remaining oil in L90 block were studied using numerical simulation and reservoir engineering methods.Using the ideal surface/polymer flooding model to evaluate the impact of reservoir permeability,oil saturation,reservoir thickness,and reservoir temperature on the enhanced oil recovery effect of surface/polymer flooding in L90 block,and conducting applicability analysis based on reservoir physical properties.Established a numerical simulation model for surfactant/polymer flooding in L90 block.Single factor analysis was used to optimize the polymer molecular weight,polymer concentration,surfactant concentration,injection volume,chemical injection slug,and injection rate.Using the L90 block surfactant/polymer flooding numerical simulation model to predict the recovery efficiency of multiple surfactant/polymer flooding schemes,and perform range analysis on the results.Designed injection proration scheme.Determine the optimal injection plan based on the development effect and economic benefits.Based on the analysis of residual oil potential and the applicability of surfactant/polymer flooding,it can be concluded that the main types of residual oil in L90 block are suitable for the development of surfactant/polymer flooding,and polymer/surface flooding has good adaptability in L90 block.Based on the above research,the optimal injection scheme has been determined.The optimal injection rate is 1200m~3/d.The pre-slug consists of polymer(16 million molecular weight,concentration 2000mg/L,injection amount 0.06PV)and surfactant(concentration 0.20%,0.05PV).The main slug consists of polymer(12 million molecular weight,1500mg/L concentration,0.2PV injection volume)and surfactant(0.20%concentration,0.05PV injection volume).The protective plug is composed of a polymer(8million molecular weight,concentration 1000mg/L,injection volume 0.04PV).The optimum surfactant/polymer flooding scheme increased the recovery by 14.68%.This research achievement proves that the surfactant/polymer flooding enhanced oil recovery technology has important application value in the L90 block.