海上稠油聚合物驱开发指标定量表征

Quantitative characterization of production indices for polymer flooding of offshore heavy oils

考虑到渤海稠油油藏的复杂性,需要定量评价不同类型油藏聚合物驱的开发指标。笔者建立了适合稠油聚合物驱开发指标定量表征模型,具有3个有明确物理意义的特征参数,包括累积注聚量下极限采收率、模型导数曲线拐点处的累积注入量等参数。利用该模型定量表征了渤海油田不同类型油藏聚合物驱开发指标。与数值模拟相比,绝对误差基本控制在0.5%以内,平均相对误差也能控制在4%以内,满足定量评价聚合物驱开发指标计算需求。该模型易于确定特征参数,且具有较好的外推性,可用于工程问题中类似增长曲线的拟合和预测。

Due to the complexity of Bohai heavy-oil reservoirs it is necessary to quantitatively evaluate production indices for polymer flooding of different reservoirs. A quantitative characterization model was establised which can evaluate production indices for poly- mer flooding of heavy-oil reservoirs. It includes 3 parameters characteristic of specific physical meanings, such as the ultimate oil re- covery of cumulative influx, the cumulative influx of polymer solution reflecting the breakpoint of derivative curves in the model, and the peak value of enhanced oil recovery corresponding to incremental oil-production curves. The model was applied to the quantitative characterization of production indices for polymer flooding of different reservoirs in the Bohai oilfield. Compared with the result of numerical simulation, the absolute error is under 0.5% with a mean relative error generally less than 4%, which satisfied require- ments of quantitatively evaluating production indices for polymer flooding of heavy-oil reservoirs. This mathematical model is suitable to the determination of specific parameters and can be well extrapolated. The model can also be used in matching and predicting simi- lar growth curves in other engineering projects.