非均质地层中烃类的扩散流和达西流可以同时存在,并可相互转换。据 Welte等 1997年计算,在致密泥岩层中,扩散流和达西流的流速分别为18m/Ma和15m/Ma,说明在致密地层中这两种流动几乎没有差别,同时说明了泥岩中的流动也可以用达西公式来表述。油、气的浮力流和渗流虽然都是在地下多孔介质中的流动,但前者是油、气在水中上浮,不呈连续相流动,而后者是油、气呈连续相与水一起流动,因此浮力流没有含烃饱和度和相对渗透率的要求,也不能用达西公式表述,而渗流则要求有临界运移饱和度和相对渗透率,并可用达西公式来计算。是否发生浮力流只取决于油、气与水的密度差,浮力流是二次运移最基本的流动模式。地下确实存在油。气的幕式运移和幕式充注,但幕式是一个有时间尺度的概念。油、气的运移和聚集是一个带幕式特征的连续过程,不能只强调强度较大的幕式活动而忽视了连续过程的存在,再加上油源的不稳定和通道的非均质性,因此单依据流体包裹体的分析就确定油气藏是由2或3期充注所形成,似乎有些难以置信。图3参18（李明诚摘） Hydrocarbon diffusive flow and Darcy flow in heterogeneous formation can co-exist and can be converted to each other. According to Welte et al.’s calculations in 1997, the velocities of diffusion flow and Darcy flow are 18m / Ma and 15m / Ma respectively in dense mudstone formations, indicating that there is almost no difference between the two flows in the dense formation, Flow can also be expressed using Darcy’s formula. Although both oil and gas buoyancy and seepage flow in the underground porous medium, but the former is oil, gas floating in the water, not a continuous phase flow, while the latter is oil, gas is continuous with the flow of water and therefore Buoyancy does not contain hydrocarbon saturation and relative permeability requirements, nor can it be expressed using Darcy’s formula, while seepage requires critical migration saturation and relative permeability, and can be calculated using Darcy’s formula. The occurrence of buoyancy depends only on the density difference of oil, gas and water. Buoyancy flow is the most basic flow pattern of secondary migration. Oil does exist underground. However, the curtain is a time-scale concept. The migration and accumulation of oil and gas is a continuous process with curtain characteristics. It can not only emphasize the strong curtain event but neglect the existence of continuous process, coupled with the instability of oil source and the heterogeneity of channel Therefore, based on the analysis of fluid inclusions, it is unbelievable to confirm that the reservoir was formed by 2 or 3 charge. Figure 3 Reference 18 (Lee Ming-cheng)