Numerical Simulation Of Chemical Viscosion-Reducing Combination Flooding For Heavy Oil In Ying 8-63 Well Area

The exploration and development of ordinary heavy oil reservoirs provide important support for China ’s economic development and national demand.In view of the difficulty of heavy oil development and low recovery rate,chemical viscosity reduction composite flooding is used to improve heavy oil recovery.Compared with conventional thermal recovery technology,polymer and viscosity reducer compound flooding technology has the advantages of easy construction and good recovery effect in heterogeneous reservoir environment.In this paper,Ying 8 block of Shengli Oilfield is taken as an example.Firstly,the mechanism of polymer and viscosity reducer flooding is analyzed,and the mechanism model of chemical flooding is established.The injection parameters of polymer flooding,viscosity reducer flooding and chemical compound flooding are optimized and the effects of different injection methods on enhanced oil recovery are compared.The three chemical flooding methods are determined to adapt to the viscosity limit of heavy oil,and the adaptability of well pattern,well spacing and row spacing of chemical compound flooding is analyzed.The simulation results show that the enhanced oil recovery of single injection polymer or viscosity reducer flooding is about 7% compared with water flooding,and the enhanced oil recovery of single chemical flooding is limited.Chemical composite flooding can combine the advantages of both polymer and viscosity reducer,and can increase oil recovery by 18.93% compared with water flooding.Taking the effect of enhanced oil recovery as the screening index,the chemical composite flooding has a good oil displacement effect in the viscosity range of 100-2000 m Pa·s heavy oil.Based on the comprehensive consideration of economic investment and oil displacement effect,chemical compound flooding technology is adopted for ordinary heavy oil reservoirs.The optimal parameters of chemical compound flooding are : injection slug volume0.6PV,polymer mass concentration 1000mg/L,viscosity reducer viscosity reduction rate 90%,injection rate 0.1PV/year and earlier injection timing.Under the same injection parameters of chemical composite flooding,the optimal well pattern is five-point well pattern,and the optimal well spacing and row spacing are set to 150m×150m.Finally,the geological model of Ying 8geological characteristics and fluid properties was established.The recovery degree of polymer and viscosity reducer chemical composite flooding technology reached 31.08%,which was15.39% higher than that of water flooding.This study provides technical support for the development of heavy oil reservoirs by chemical flooding,and uses chemical flooding technology for feasibility analysis and enhanced oil recovery evaluation for different heavy oil viscosity reservoir environments,effectively promoting the development and application of chemical flooding technology in heavy oil reservoirs.