特高孔高渗稠油油藏化学驱可行性研究

Study on the Feasibility of Chemical Flooding for Super High Porosity and High Permeability Heavy Oil Reservoirs

针对渗透率高于10μm^(2)及孔隙度大于35%的特高孔高渗稠油油田,开展化学驱可行性研究。研究了部分水解聚丙烯酰胺类聚合物、结构聚合物、稠油活化剂和凝胶4种驱油体系剪切前后的黏浓关系。结果表明:普通聚合物和稠油活化剂剪切前后黏度均较低,结构聚合物剪切前后黏度较高,并且质量浓度越高,黏度保留率越高,凝胶体系黏度最高,抗剪切能力最好。进一步研究了结构聚合物和凝胶体系的阻力系数和残余阻力系数,结果表明渗透率、流速及聚合物质量浓度均对阻力系数和残余阻力系数造成影响,从阻力建立能力角度出发,认为结构聚合物不适应于10μm^(2)以上渗透率地层;凝胶体系比结构聚合物驱油体系建立阻力系数的能力更强,针对渗透率高于10μm^(2)的油藏,凝胶体系建立流动阻力的能力较好。

The feasibility study of chemical flooding was carried out for ultra-high porosity and high permeability heavy oil field with permeability higher than 10 μm^(2) and porosity greater than 35%. The viscosity-concentration relationships of four kinds of oil flooding systems including hydrolyzed polyacrylamide, hydrophobically associating polymer, heavy oil activator and gel were studied. The results showed that the viscosity of ordinary polymer and heavy oil activator were lower than other two types of oil displacement agents, and the viscosity of hydrophobically associating polymer was higher. The higher the concentration was, the higher the viscosity retention rate was. The gel system had the highest viscosity and best anti-shear ability. The resistance coefficient and residual resistance coefficient of hydrophobically associating polymer and gel system were further studied. The results showed that permeability, velocity and polymer concentration all affected the resistance coefficient and residual resistance coefficient. From the point of view of resistance establishment ability, it was considered that hydrophobically associating polymer was not suitable for formations with the permeability above 10 μm^(2). Gel system had stronger ability to establish resistance coefficient than hydrophobically associating polymer flooding system, and it was more feasible for formation system with permeability above 10 μm^(2).