Abstract: It is always the key point in the field of oilfield development to study the oil circulation condition and percolation law in reservoirs.Based on the percolation theory,a three⁃dimensional percolation model is established by numerical simulation method,which can simulate the distribution of cracked joints,percolation laws,percolation thresholds of reservoir rocks and determine whether they are permeable.The results show that when the connectivity probability increases from 0,the total number of clusters increases.When the connectivity probability increases to 0.17,the total number of clusters begins to decreases.When the connectivity probability is small,the percolation probability increases slowly with the increase of the connectivity probability.When the connectivity probability exceeds the first critical value,the growth rate of the percolation probability suddenly increases.When the connectivity probability exceeds the second critical value,the percolation probability begins to slowly increase again and eventually approaches 1.The seepage cluster can accurately determine whether the porous medium is permeable and accurately capture the percolation threshold.The size of the percolation threshold is related to the size and shape of the medium.There is no obvious regularity between the maximum cluster size and the average cluster size,the maximum cluster size and the total number of clusters.It is concluded that this three⁃dimensional percolation model can simulate the long⁃range coupling mutation caused by the change of connectivity probability in porous media,which can be used to simulate the permeability and percolation law of rock.

Key words: Three?dimensional percolation model, Numerical simulation, Percolation law, Permeability, Percolation probability

摘要： 研究储层中的石油流通状况与逾渗规律，一直是油田开发领域的重点。基于逾渗理论，运用数值模拟方法建立三维逾渗模型，能够模拟储层岩石的裂缝连通团分布情况、逾渗规律、逾渗阈值，并判断其是否可渗透。结果表明，连通概率从0开始增加时，总簇数增加。连通概率增加到0.17时，总簇数开始减少；连通概率较小时，逾渗概率随着连通概率的增加缓慢增加，连通概率超过第一临界值时，逾渗概率的增长率突然增大，连通概率超过第二临界值时，逾渗概率再次开始缓慢增加并最终趋近于1；渗流集群可以准确地判定多孔介质是否可渗透，精准捕捉逾渗阈值。逾渗阈值的大小与介质的尺寸和形状都有关；最大簇大小与平均簇大小、最大簇大小与总簇数之间的关系没有明显的规律性。结论认为，此三维逾渗模型能够模拟多孔介质中由于连通概率变化所引起的长程联结性突变，可以用它模拟岩石的渗透性与逾渗规律。

关键词: 三维逾渗模型, 　数值模拟, 　逾渗规律, 　渗透性, 　逾渗概率