一次和二次聚合物驱驱替液与原油黏度比优化研究

研究了不同原油黏度原油油藏一次聚合物驱和二次聚合物驱时驱替液与原油黏度比对提高采收率的影响,并对合理黏度比区间进行了优化。研究结果表明:在相同原油黏度条件下,随着黏度比的增大,聚合物驱提高采收率幅度变大,但黏度比大到一定程度后采收率提高幅度的增加不明显;在相同黏度比条件下,二次聚合物驱采收率提高幅度明显低于一次聚合物驱,如果要达到一次聚合物驱时的采收率提高幅度,则需要较高的黏度比;二次聚合物驱时,聚合物注入时机越早越好。绘制了合理黏度比的理论图版,利用该图版可以检验矿场实施单元注入参数的合理性,且为一次聚合物驱及二次聚合物驱的合理注入参数设计提供了依据。

Optimization of oil-to-polymer viscosity ratios in the primary and secondary polymer flooding

The influences of oil-to-polymer viscosity ratios in the primary and secondary polymer flooding on the enhanced oil recovery (EOR) in thin or heavy oil reservoirs were researched systematically. The reasonable range of oil-to-polymer viscosity ratio was optimized. The result shows that the increment of EOR gets larger with the increase of the oil-to-polymer viscosity ratio under the condition of the same crude oil viscosity, and the increment of EOR is unconspicuous while the viscosity ratio reaches to a certain value. The increment of EOR in the secondary polymer flooding is obviously lower than that in the first polymer flooding under the condition of same oil-to-polymer viscosity ratio. Higher oil-to-polymer viscosity ratio would be needed to reach the value of the primary polymer flooding. The earlier injection of polymer would get the better effect in the secondary polymer flooding. A theoretical plate could be used to check rationality of the injection parameters in the field and to provide basis for designing the reasonable injection parameters in the primary and secondary polymer flooding.