特低渗透储层油水两相非达西渗流特征

Characteristics of non-Darcy flow velocity of oil-water phases in extra-low permeability reservoirs

以榆树林地区特低渗透岩样油水两相渗流实验为实例,对特低渗透岩样在不同含水饱和度下的拟启动压力进行了研究,通过对实验数据进行的理论分析,得到了描述油水两相非达西渗流的经验关系式。对稳态法测定的特低渗透岩样油水两相相对渗透率曲线进行研究的结果是:当空气渗透率小于2×10-3μm2时,油水的相对渗透率就依赖于油水渗流速度,对油相影响较大,流速越低,油相相对渗透率也越低,油水两相同时渗流时的拟启动压力比单相时要大很多。

The oil-water phases seepage experiment on the extra-low permeability samples produced from Yushulin Oil Field were taken for example to illustrate the researches of pseudo-kickoff pressure of extra-low permeability samples under different water saturations. Empirical relationship defining the oil-water non-Darcy flow was achieved by theoretically analyzing the experiment data. The analysis result of relative permeability curve of oil-water phases in extra-low permeability samples measured by stable state method shows that when the air permeability is less than 2×10^-3μm^2, the relative permeability of oil and water with inclining dependence on oil-water seepage velocity, has larger influences on oil phase, the lower velocity, the lower oil phase relative permeability, and the pseudo-kickoff pressure of oil-water phases simultaneous seepage is much larger than that of single phase.