聚合物驱阶段提高采收率预测模型的建立与应用

Establishment and application of a prediction model for enhanced oil recovery in polymer flooding

为了预测聚合物驱开发指标,根据实际生产数据,综合应用驱替特征曲线和经验回归方法,建立了聚合物用量与提高采收率变化规律的预测模型。并对A油田39个一类油层和二类油层聚合物驱区块进行拟合和预测,计算结果表明:在半对数坐标系下,聚合物用量与提高采收率成线性关系;在聚合物驱的含水稳定阶段与含水回升阶段,该方法预测精确度较高,提高采收率绝对误差为0.01%～0.58%,相对误差为0.09%～6.24%。该预测模型能够应用于聚合物驱的长远规划与年度规划,也可用于聚合物驱开发调整措施效果评价和确定单井组转后续水驱时机。

In order to predict the development index of polymer flooding, a new model to predict the polymer volume and variation laws of enhanced oil recovery was established by applying actual production data, displacement curves and experience regression methods. With the application of this model to 39 polymer flooding blocks of the primary and second oil layers of an oilfield, the cal- culation results indicated that the polymer volume shows a linear relation with enhanced oil recovery in the semi-logarithm coordinates and the scope of enhanced oil recovery by polymer flooding is bounded. At the stable and regressive water bearing stages of polymer flooding, this model is of the relatively high prediction accuracy, with the absolute and relative average error of enhanced oil recovery ranging between 0. 01% ~0. 58%and 0.09% ~6.24%, respectively. Therefore, this model can be applied not only to the annual and long-term planning of polymer flooding but also to the evaluation of development adjustment and the determination of time for well groups to shift from polymer flooding to subsequent water flooding.