低渗透油藏油水相对渗透率模型的分形表征方法

Fractal characterization method of oil-water relative permeability model in low permeability reservoirs

在多孔介质分形理论基础上,建立低渗透储层油水相对渗透率数学模型,研究储层孔隙结构、驱替压力、油相剪切应力、毛细管压力对油水相对渗透率曲线形态的影响。结果表明:随驱替压力的增加,油相相对渗透率逐渐增加,对水相相对渗透率影响较小;水相剪切应力对相对渗透率曲线的形态影响较小;油相剪切应力对相对渗透率曲线的形态影响较大,随油相剪切应力的增加,油相相对渗透率减小;迂曲度对水相、油相相对渗透率影响较大,迂曲度越大,水相和油相相对渗透率越小;毛细管压力越大,油相相对渗透率越小,水相相对渗透率越大。该结果为认识储层流体的渗流规律提供指导。

Based on the fractal theory of porous media,the mathematical model of oil-water relative permeability of low permeability reservoirs was established to study the effects of pore structure,displacement pressure,oil phase shear stress and capillary pressure on oil-water permeability curve.The results show that with the increase of displacement pressure,oil phase relative permeability increases gradually and exerts less effect on water phase relative permeability.The shear stress of aqueous phase has little effect on the morphology of relative permeability curve.The relative permeability of oil phase decreases with the increase of the shear stress of oil phase.The degree of tortuosity has a great effect on the relative permeability of water phase and oil phase,and the greater the degree of tortuosity,the smaller the relative permeability of water phase and oil phase.The higher the capillary pressure,the smaller the oil phase relative permeability and the greater the water phase relative permeability.The results provide guidance for understanding the seepage law of reservoir fluid.