Sun Xianda, Zhao Mengqing, Fan Xiaoqi, Zhang Yongsheng, Xu Chengwu, Wang Lihui, Sang Guoqiang
Key Laboratory of "Continental Shale Oil and Gas Accumulation and Efficient Development" of Ministry of Education, Northeast Petroleum University, Daqing 163318, China.
Postdoctoral Research Workstation of Daqing Oilfield, Daqing 163458, China.
Polymers (Basel). 2022 Feb 23;14(5):878. doi: 10.3390/polym14050878.
To study the microscopic production mechanism of corner residual oil after polymer flooding, microscopic visualization oil displacement technology and COMSOL finite element numerical simulation methods were used. The influence of the viscosity and interfacial tension of the oil displacement system after polymer flooding on the movement mechanism of the corner residual oil was studied. The results show that by increasing the viscosity of the polymer, a portion of the microscopic remaining oil in the corner of the oil-wet property can be moved whereas that in the corner of the water-wet property cannot be moved at all. To move the microscopic remaining oil in the corners with water-wet properties after polymer flooding, the viscosity of the displacement fluid or the displacement speed must be increased by 100-1000 times. Decreasing the interfacial tension of the oil displacement system changed the wettability of the corner residual oil, thus increasing the wetting angle. When the interfacial tension level reached 10 mN/m, the degree of movement of the remaining oil in the corner reached a maximum. If the interfacial tension is reduced, the degree of production of the residual oil in the corner does not change significantly. The microscopic production mechanism of the corner residual oil after polymer flooding expands the scope of the displacement streamlines in the corner.
为研究聚合物驱后角部残余油的微观产出机理，采用微观可视化驱油技术和COMSOL有限元数值模拟方法，研究了聚合物驱后驱油体系的黏度和界面张力对角部残余油运移机理的影响。结果表明，通过提高聚合物的黏度，能使部分亲油性质角部的微观残余油发生运移，而亲水性质角部的微观残余油则完全无法运移。要使聚合物驱后亲水性质角部的微观残余油发生运移，必须将驱替液黏度或驱替速度提高100 - 1000倍。降低驱油体系的界面张力会改变角部残余油的润湿性，从而增大润湿角。当界面张力降至10 mN/m时，角部残余油的运移程度达到最大。若进一步降低界面张力，角部残余油的产出程度变化并不显著。聚合物驱后角部残余油的微观产出机理拓宽了角部驱替流线的范围。
