低渗透非均质油藏径向渗流特征研究

THE RADIAL PERCOLATING CHARACTERISTICS OF LOW PERMEABILITY IN NON-HOMOGENEOUS RESERVOIRS

利用实验手段回归出启动压力梯度与渗透率的相关式,并用此式得出非均质油藏的启动压力梯度分布,建立了考虑启动压力梯度的三维三相径向坐标下的渗流数学模型和有限差分方程。有限差分方程中每个网格块上的启动压力梯度可以考虑为不同值,网格块上的启动压力梯度值可由初始化参数场给定,编制了相应的软件,并对比了低渗非均质储层不考虑启动压力梯度、启动压力梯度为常数和启动压力梯度非均匀分布时的压力分布特征。

By means of the equation of threshold pressure gradient and permeability regressed by experimental method, and the threshold pressure gradient distribution of heterogeneous reservoirs which is derived from the equation, the math model of flowing through porous media and infinite differential equation at three dimentions and three phases radius axis considering threshold pressure gradient. The threshold pressure gradient at each grid in the equation can be considered as different value, and the threshold pressure gradient value at the grid can be given by initial parameter field, corresponding sofeware is developed, the comparision is done under the conditions of not considering threshold pressure gradient, constent threshold pressure gradient and unevenly distributed threshold presuure gradient.