The Effect Of Displacement Pore Volume On Oil Displacement Efficiency

In the near-well zone,the closer to the pore volume multiples well,the higher the pore volume multiples ratio.As the distance from the injection well increases,the displacement factor decreases.To improve oil recovery by water flooding or polymer flooding,the influence of different displacement multiples of water flooding and polymer flooding on oil displacement effect should be obtained first.At the same time,the displacement multiple also affects the dynamic adsorption retention and residual resistance coefficient.It is necessary to study the effect of different displacement multiples on oil displacement by using two polymers with different performance.Through water flooding experiment,the influence of water displacement pore volume multiples on oil displacement efficiency is studied,and the following conclusions are drawn:1)Permeability of 1500mD water displacement pore volume multiples on oil displacement efficiency,the maximum oil recovery is 71.7%when injecting 100PV;2)Permeability of 2000mD water displacement pore volume multiples on oil displacement efficiency,the maximum oil recovery is 63.9%when injecting 100PV;3)With the increase of injection rate,water flooding recovery will increase.With the increase of the number of injected PV,the recovery rate shows a sharp decline first and then a steady trend,and the faster the rate is,the faster the decline is;in all stages,the recovery rate of injected 0?0.1 PV is the largest.Through the study of the influence of injecting polymer solutions with different displacement multiples on pressure,the following conclusions can be drawn:1.The pressure of injecting 9 PV AP-P4 polymer solutions is stable at 1.15 MPa,and the pressure of injecting 2PV FP3640C polymer solutions is stable at 0.22MPa;2.The flow resistance of polymer AP-P4 is greater than that of polymer FP3640C;and the dynamic adsorption lag of AP-P4 solution increases with displacement multiples.The larger the retention,the less the dynamic retention in porous media with the increase of temperature,and the overall adsorption capacity is larger than that of FP3640C polymer.In the influence of displacement ratio of Polydrive displacement pore volume multiples efficiency.With the increase of injection rate,the recovery decreases.When 0?1PV is injected,recovery of 0.1 PV is much larger than other stages;with the increase of injection PV number,recovery shows a sharp decline first and then a steady trend,and after injection of 40PV,recovery tends to be stable.Comparing the displacement effect of water flooding with that of polymer flooding,the following conclusions can be drawn:(1)with the increase of injection rate,the water flooding recovery increases gradually and the polymer flooding recovery decreases gradually;(2)when injecting 0?1PV,the polymer flooding recovery is greater than that of water flooding,and when injecting less than 1PV,the polymer flooding effect is better;(3)when injecting 1PV?100PV,the water flooding recovery is greater than that of polymer flooding,and the water flooding effect is better.