Evaluation of the development effect of polydynamic drive in Class IIB oil reservoir of Lamadian Oilfield

Abstract

With the continuous deepening of oilfield development, the target of oilfield development is gradually shifting towards reservoirs with poor physical properties, and polymer flooding can better utilize such reservoirs.The heterogeneity of Class II B oil layer in Lamadian Oilfield is severe, and polymer flooding takes effect later, with a small decrease in watercut.A study was conducted on the evaluation of polymer flooding development effectiveness for Class II B oil layers through reservoir numerical simulation . Research has shown that when the initial watercut is constant, a lower injection pressure can increase the utilization degree of remaining oil in the middle and high permeability layers of Class II B oil layers. With the increase of injection pressure, the response time is shortened, and the decrease in watercut is reduced; As the watercut increases, the injection pressure should gradually increase in order to improve the recovery of low permeability reservoirs;As the watercut increases, the injection pressure should gradually increase in order to improve the recovery of low permeability oil layers;At a watercut of 95% and injection pressure of 7MPa, a field experiment was conducted with a molecular weight polymer of 12 million , and the response time was 6 months. The cumulative oil increase was 14675m3, achieving good polymer flooding effect.