碳酸盐岩裂缝介质中微观二维油水运移聚集物理模拟实验研究

裂缝是碳酸盐岩中流体流动最主要的通道和重要的储集空间。碳酸盐岩裂缝介质中的油水运移和聚集过程研究是我国的一个研究热点，也是一个国际性难题。利用物理模拟实验来研究碳酸盐岩裂缝中的油气运移是一个新的尝试。实验利用碳酸盐岩裂缝岩心制作成薄片模型，在薄片模型中进行油驱水实验来模拟运移过程。实验结果表明：①流体平面流动路径有单一式／平行式、斜交式和网络式三种路径；在通道内流体运移形态有连续式、分段式及连续一分段式三种；油水驱替前缘呈现活塞式、绕流式和脉冲式三种形式。②流体流动形态随流体压力、饱和度、裂缝结构、润湿性等因素的变化而变化。这些因素之间相互影响，交叉作用。流体压力和流量，流体压力和流体速率有条件呈现相关关系；流体速率不仅与压力相关，而且与裂缝发育的角度和宽度有关，与压力梯度夹角较小的宽裂缝内的流体速率较高，反之较低。

Experimental Study on Water-Oil Migration and Accumulation in 2-D Micro-Model of Carbonate Fractures Media

There are many achievements in the hydrocarbon migration experimental studies in clastic reservoir, while there are few migration experiments reported in the carbonate reservoir simulations realm. This article is a tentative experimental study on hydrocarbon migration and accumulation in the carbonate reservoir, a complex media, including porosity system and fracture system. This microcosmic experiment simulates oil-water displacement with real core model. Plentiful seepage phenomena were observed in the microcosmic experiments. Three pathways found in the plane pathway include parallel pathway, lean-cross pathway and network pathway. Three types of flow were found, continuous flow, sectioning flow and their combination. Three driving fronts were found in experiment, piston front, encircle front and impulsive front. All these vary with many factors such as fluid pressure, oil saturation, fissure configurations and wettability, and these factors affect each other. The result show that the relation between the fluid pressure and volume of flow is complex segmenting correlative, instead of simple normal correlativity like the pipe flow which follows the Darcy laws, so is that of the fluid pressure and the speed of flow. The speed of flow relates to angle and width of fissure. The speed of flow in the wide fissure that has acute angle with pressure grad is higher than that of narrow fissure with high angle with pressure grad.