普通稠油油藏水驱开发面临原油黏度高、指进严重且采收率低的问题，亟需转换开发方式，进一步提高采收率。以孤岛油田B21单元普通稠油油藏为目标区，通过数值模拟，建立了不同原油黏度油藏聚合物驱的驱替相与原油合理黏度比界限图版；通过室内增黏实验，确定目标区适用的聚合物质量浓度界限；再采用数值模拟方法，优化确定聚合物最佳注入浓度；结合物理模拟实验，优化高低浓度交替注入方式，相同聚合物用量下可更大幅度提高采收率；考虑开发效果和经济性两方面指标，制定了不同原油价格和不同聚合物价格下聚合物经济极限用量界限图版，对普通稠油油藏聚合物驱持续经济高效开发具有重要指导意义。现场应用结果表明，截至2021年7月，日产油量由285 t/d最高上升至441 t/d，最大升幅为156 t/d，综合含水率由89.1%最低降至76.2%，最大降幅为12.9%，已累积增油量为61.4×104 t，已提高采收率达7.0%，降水增油效果显著。
The water-flooding development in ordinary heavy oil reservoirs faces the problem of low oil recovery due to high crude oil viscosity and serious fingering. It is urgent to change the development method to further enhance oil recovery. Taking the ordinary heavy oil reservoirs in Block B21，Gudao Oilfield as the target area，through numerical simulation，we established the boundary chart of the reasonable viscosity ratios between the displacing phase and crude oil for polymer flooding in reservoirs with different crude oil viscosity. Through indoor viscosity-increasing experiments，we determined the polymer concentration limit applicable to the target area. Then numerical simulation was conducted to optimize and determine the best polymer injection concentration. Combining physical simulation experiments，we optimized the alternate in? jection method of high and low concentrations，thereby greatly improving oil recovery under the same polymer usage. Considering development effect and economic efficiency，the usage chart of economic limits under different crude oil and polymer prices was formulated，which can significantly guide the economic and efficient development of polymer flooding in ordinary heavy oil reservoirs. Field application results showed that as of July 2021，the daily oil production has witnessed a maximal increase of 156 t/d from 285 t/d to 441 t/d，and the composite water cut has seen the largest decrease of 12.9% from 89.1% to 76.2%. The cumulative oil increment was 61.4×104 t，and the oil recovery has improved by 7.0%，achieving an obvious effect of oil production increase and water cut decrease.