聚合物驱替簇状残余油效果的影响因素

Influencing Factors of Polymer Displacement of Cluster Residual Oil

曹 苗 郭拥军 冯茹森

CAO Miao GUO Yongjun FENG Rusen

为进一步揭示聚合物微观驱油规律及机理， 针对簇状残余油 “大孔包围小孔” 的孔隙结构， 设计了理想化簇 状残余油微观驱替可视模型， 系统研究了驱替线速度、 驱油体系黏弹性、 孔隙结构、 原油黏度对簇状残余油采收 率的影响。结果表明， 驱替线速度增加所带来驱替压力的提高是簇状残余油采收率增加的主要原因； 驱油体系 黏度相同时， 弹性越大越有利于残余油驱替； 小孔道宽度固定， 变径比高于临界变径比时， 簇状残余油难以驱替； 变径比相同， 小孔道宽度低于临界小孔道尺寸时采收率近乎为零； 原油黏度增大， 簇状残余油采收率迅速减小。 模拟油黏度、 第一法向应力差、 驱替线速度对簇状残余油采收率的影响程度依次由大到小。图28表 4参19

In order to further reveal the microscopic rule and mechanism of polymer flooding， according to the pore structure， the idealized microscopic displacement visual model was designed， and then the effects of displacement speed， polymer viscosity， pore structure and oil viscosity on the displacement efficiency of cluster-residual oil was systematically studied. The results showed that the increasing velocity led to the increase of the displacement pressure， which was the main reason for the increase of displacement efficiency. When the viscosity of the displacement system was the same， the greater the elasticity was， the easier it was to displace the residual oil. When the variable diameters ratio was higher than critical value， and the small pore width was fixed， the cluster residual oil was difficult to be displaced；on the contrary， when the variable diameters ratio was the same， and the small channel width was lower than critical value， the oil displacement efficiency was almost zero. With the increase of the oil viscosity， the displacement efficiency of cluster-residual rapidly reduced. It was concluded that the influence of concerned factors on the oil recovery in a decreasing order including oil viscosity， the first normal stress difference， displacement velocity.