聚合物驱效果影响因素关联性及适应性分析

Analysis on correlation and adaptability of factors affecting polymer flooding efficiency

聚合物驱是一项复杂而且具有多目标性的系统工程,对聚合物驱影响因素进行排序对聚合物驱的实施调整有一定指导意义。将聚合物驱看成灰色系统,用灰色关联分析的方法分析各种影响因素对聚合物驱效果的关联度,确定出影响措施效果的主要因素。统计了河南油田8个已注聚区块的开发效果,选取了渗透率变异系数,地层温度等9个因素作为主要影响因素,经灰色关联分析得出,该油田聚合物驱效果影响因素影响程度从大到小排序:注入速度>地层温度>渗透率变异系数>地层水矿化度>注入孔隙体积>段塞尺寸>地层渗透率>原油黏度>聚驱前含水。建立了典型模型,针对主控因素对聚合物驱的适应性进行了分析,结果表明,随着注入速度的增加,聚合物驱提高采收率幅度降低;聚合物工作黏度对开发效果的影响曲线呈明显的二段式分布;渗透率变异系数在0.7附近时聚合物驱效果最佳。

Polymer flooding is a complex and systematic project with multiple targets. To sort the influence factors in sequence is valuable to implement and adjust the polymer flooding. By regarding the polymer flooding as a gray system, the gray correlation analysis method is used to analyze the effect of various factors on polymer flooding, as a result, the main factors affecting the polymer flooding is identified. Statistics is taken on the development effect of eight polymer flooding blocks in Henan Oilfield. The permeability variation coefficients are selected, and nine factors including the formation pressure are identified as the dominant ones. Based on the analysis, the factors are sorted in a descending order： the injecting rate, the formation pressure, the permeability variation coefficient, the formation water salinity, the injection pore volume, the size of broken plug, the permeability, the oil viscosity, and the water cut before polymer flooding. A series of conceptual models are established for the analysis of the adaptability of the polymer flooding. It is shown that the oil recovery based on polymer flooding increases more slowly as the injecting rate increases. The polymer flooding response changes at the specific polymer eftective viscosity, and the polymer flooding reaches its best response when permeability variation coefficient equals 0. 7.