测定相渗曲线时发现,聚驱后续水驱阶段与单纯水驱的相渗曲线出现完全不同的变化趋势,后者的油水相对渗透率比Kro/Krw与对应含水饱和度Sw在半对教坐标系下具有良好的线性关系,而前者的油水相对渗透率比与对应含水饱和度在直角坐标系下就具有良好的线性关系。以此为基础,推导出了后续水驱阶段的驱替特征模型,包括采出程度与油水比的关系及累积产水量与累积产油量的关系。利用大庆油田已有后续水驱数据的区块对建立的后续水驱驱替特征模型进行了验证,采出程度与油水比之间的线性相关系数均大于0.9,满足良好的线性关系,Wp与lg(AN—Np)在直角坐标系下也满足良好的线性关系,线性相关系数达到0.99以上。利用所建立的驱替特征模型可以准确地预测聚驱后续水驱阶段的开发指标。
Based on the measurement it noticed that the relative permeability curve in the follow-up water drive phase after polymer-flooding is different from the curve in the water drive phase. The linearity between oil/water relative permeability ratio and water saturation in the water drive phase was excellent in semi-log coordinate while the linearity in the follow-up water drive phase was excellent in Cartesian coordinate. The mathematical model of displacement performance in the follow-up water drive phase was given based on the previous performance, including the correlation between degree of recovery and oil/water ratio, the correlation between cumulative water production and cumulative oil production. The model was verified using actual data of follow-up water driving blocks in Daqing Oilfield. The correlative coefficients between degree of recovery and oil/water ratio exceeded 0.9 and the correlative coefficients between and exceeded 0.99, the linearity was excellent. This model can predict development index of the follow-up water drive phase accurately.