Parameter Optimization And Scheme Design Of Gel Flooding Injection In P16 Well Area

The P16 well area is a medium-low permeability reservoir with strong heterogeneity.Since its development in 1980,after three stages of basic well pattern mining,primary uniform infilling adjustment and secondary non-uniform infilling adjustment,as of August 2018,the composite water cut of the P16 well area reached95.46%,and it has entered the extra-high water cut development period,but the recovery factor is only 40.50%.Continued use of water flooding is not effective,recovery is slowly increasing,and economic benefits are poor.Aiming at the characteristics of medium-low permeability heterogeneous reservoirs in P16 well area and the development status of high water cut and low recovery,and learn from the application of profile control and flooding technology in adjacent well areas.Proposed the use of weak gel control technology with strong injection ability,controllable gelation time and good profile controlling displacement effect.The numerical simulation method is used to optimize the injection scheme of weak gel flooding control in the P16 well area,and solve the problems of rapid increase of water cut and low recovery factor in the development process.In this paper,first established the 3D geological model by Petrel,and then import CMG to establish the numerical simulation model and perform water flooding history matching.Determined and analyzed the distribution characteristics of remaining oil and the potential for tapping of remaining oil.Based on the numerical simulation model of water flooding,optimize the injection parameters of flooding system and design the profile control scheme.P16 well area adopts complex-slug injection(pre-slug+main slug+post slug).The optimal injection scheme is determined by comparative analysis of the enhanced recovery factor and reduced water cut,that is,the injection rate of the control system is 0.07PV/a,the injection concentration of each slug(polymer-crosslinking agent-stabilizer)is:per-slug 800-1800-200 mg/L,main slug 700-1600-200mg/L,post slug 900-1800-200 mg/L,the injection volume of the control system is0.29PV.Based on the optimum scheme,the single well injection volume of the injection well are calculated and determined the optimal single well injection volume.Finally,carried out the development index prediction,the enhanced recovery rate of the whole area is 4.69%,and the cumulative oil increase is 6.226×10~4t,the effect of flooding control and economic benefits are good.