相渗曲线判断聚合物驱转注聚时机的应用方法

Application method of determining polymer injection timing with relative permeability curves

早期注聚技术能够进一步提高聚合物驱效果,室内实验和数值模拟进行转注聚时机的判断方法相对复杂且应用受限。以油水相渗机理为基础,应用油藏工程方法建立一种快速确定转注聚时机的应用方法。通过室内实验获得了4个油藏的相渗曲线特征,并应用油藏工程方法分析了不同油藏条件下的含水率变化规律、含水率上升速率、无因次采液(油)指数、油水流度比等特征参数对聚合物驱注入时机的影响。研究结果表明,不同油藏条件下的上述特征参数规律差异明显,聚合物驱转注聚时机应该是根据矿场实际需求排序各特征参数,再进行转注聚时机的确定。以产量为核心的排序指标为例,无因次采油指数>无因次采液指数>含水率上升速率>油水流度比,从而确定出四个油藏(BZ、JZ、QHD、SZ)的转注聚时机含水率分别是>80%、>79.9%、>86%、>34%。结合矿场实际情况,应用油藏工程方法分析相渗曲线可以快速确定转注聚时机。

The early polymer injection technology can further improve the polymer flooding effect,and the method to judge the time of polymer transfer by laboratory experiment and numerical simulation is relatively complex and limited in application.Based on the mechanism of oil-water relative permeability,an application method for quickly determining the time of injection and accumulation is established by using reservoir engineering method.The characteristics of the relative permeability curves of four reservoirs are obtained through laboratory experiments,and the influence of the water cut change rule,water cut rise rate,dimensionless production fluid(oil)index,oil-water mobility ratio and other characteristic parameters on the injection timing of polymer flooding under different reservoir conditions is analyzed by the reservoir engineering method.The results show that the above characteristic parameters are obviously different under different reservoir conditions.The injection time of polymer flooding should be determined by sorting the characteristic parameters according to the actual demand.Taking production as an example,the dimensionless production index,dimensionless production index,water cut rising rate and oil-water flow rate ratio determine that the water cut of the injection time for four reservoirs(BZ,JZ,QHD and SZ)is above 80%,79.9%,86%and 34%,respectively.According to the actual situation of the field,the time of polymer injection time can be determined quickly by analyzing the relative permeability curve with reservoir engineering method.