Study on injection rate of third level formation with polymer flooding in Daqing Oilfield

Injection rate is one of the important factors that influences polymer flooding effect.But because of the limitation of postulated condition of numerical simulation model,injection rate determined cannot reflect the influence of polymer solution elasticity.The purpose of this paper is to give reasonable injection rate for third level formation in Daqing oil field.The displacement experiments were done to study oil displacement efficiency of water flooding and polymer flooding at different displacing rate.Experiment result shows that the relationship between polymer flooding enhancing efficiency and displacing rate can be expressed by quadratic polynomial.Based on this relationship,the reasonable injection rate model was established combining with seepage flow rate of fluid in the formation obtained by principle of potential superposition.And proposed reasonable injection rate was 0.288 PV/a for third level formation in Daqing oil field at the present well spacing of 100 meters.The method has important signification for drawing up development plan of oilfield.