单一缝洞内油水相对渗透率及其影响因素

Oil-water relative permeability and its influencing factors in single fracture-vuggy

将复杂的缝洞系统简化为裂缝和溶洞的基本组合,从分析油水相对渗透率曲线着手探索其两相流动规律。在考虑实际油田碳酸盐岩储层特征的基础上,制作不同溶洞直径的单一缝洞有机玻璃模型,利用稳态法测定模型中的油水相对渗透率研究溶洞直径、缝洞倾角、油水黏度比、注入速度等因素对油水相对渗透率的影响。结果表明:对于单溶洞单裂缝的基本组合,随着溶洞直径的增大,油相相对渗透率曲线由直线型逐渐转变为下凹型,水相相对渗透率曲线呈上凹型且曲率越来越大;残余油饱和度随着溶洞直径、缝洞倾角、注入速度的增大和油水黏度比的减小而降低。

The complex fracture-vuggy system can be simplified as basic combination of fractures and caves. The two-phase flow laws were researched by analyzing water-oil relative permeability curves. Based on the reservoir characteristics of the carbonate rock of practical oilfield, single fraeture-vuggy organic glass models with different vuggy diameter were made. Oil- water relative permeability curves were measured by using steady-state method. The influence of vuggy diameter, fracture- vuggy dip, oil-water viscosity ratio and injection rate on oil-water relative permeability curves was studied. The results show that in the models composed of single fracture-vuggy, the shape of oil relative permeability curve changes from linear type to down-concave type with the increase of vuggy diameter. The shape of water relative permeability curve is up-concave type, and the curvature of the curve increases with the vuggy diameter increasing. Residual oil saturation decreases with the in- crease of vuggy diameter, fracture-vuggy dip and injection rate, and the decrease of oil-water viscosity ratio.