低渗透油层低黏度聚驱微观剩余油动用机理

Microscopic residual oil utilization mechanism of low viscosity polymer flooding in low permeability reservoir

王国锋

WANG Guofeng

大庆榆树林油田开发有限责任公司，黑龙江 大庆 163000

Yushulin Oilfield Company Limited of Daqing, Daqing 163000, China

为了描述低黏度聚合物对于低渗透油层剩余油挖潜效果，采用微观驱油实验和天然岩心解剖实验，研究在低黏度聚合物溶液作用下低渗透油藏驱油效果，以及改变黏度后各类剩余油动用状况。结果显示：对于相同孔喉比孔隙结构而言，聚合物黏度越大，剩余油分布比例越小，随着黏度的增大，低黏度聚合物体系最小压力梯度增大，从而克服压敏、贾敏等阻力效应，改善各类剩余油的动用状况；在可注入条件下，与水驱相比，随着聚合物黏度的增大，采收率提高值最高可达到5.78 百分点，从而验证了低黏度聚合物驱在低渗透油层的可行性，为低渗透油藏改善驱油效果提供理论支持。

In order to describe the tapping potential of low viscosity polymer for remaining oil in low permeability reservoirs, micro-displacement experiment and natural core anatomy experiment were used to study the effect of low viscosity polymer solution on oil displacement in low permeability reservoirs, and the production status of various remaining oil after changing viscosity. The results show that for the same pore throat ratio of pore structure, the higher the viscosity of polymer, the smaller the proportion of residual oil distribution. The minimum pressure gradient of low viscosity polymer system increases with the increase of viscosity, so as to overcome the pressure sensitivity and Jamin effect resistance effect and improve the utilization of various types of residual oil. With the increase of polymer viscosity, the maximum enhanced oil recovery can reach 5.78% compared with water flooding, which verifies the feasibility of low viscosity polymer flooding in low permeability reservoirs and provides theoretical support for improving oil displacement effect in low permeability reservoirs.

10.6056/dkyqt201806018