平行裂缝中单相流动模式研究

STUDY ON SINGLE-PHASE FLOW PATTERN IN PARALLEL FRACTURES

在基岩渗透率较低的缝洞型碳酸盐岩油藏中，裂缝渗透率对流体流动起着非常重要的作用。采用实验方法研究了平行裂缝中单相流体的流动特点。裂缝模型由大理石和不锈钢垫片组装而成，裂缝张开度由垫片厚度决定。单相流体在平行裂缝中流动可分为线性和非线性流动区域。用阻力系数和雷诺数分析实验数据发现，在线性流动区域内，阻力系数随雷诺数的增加而减小；而在非线性流动区域内，阻力系数不随雷诺数变化。根据实验结果，建立了平行裂缝中的流动模式，并确定了流动模式之间的转换条件。

In the fractured vuggy carbonate oil reservoirs with much lower matrix permeability, the fracture perme- ability plays a very important role in the fluid flow. This paper studies the single-phase flow characteristics in parallel fractures by using the experimental methods. The fracture model is made of marble blocks and stainless steel spacers. The fracture aperture varies with the thickness of the spacers. The above flow can be divided into linear and non-linear flow regions. The experimental data are analyzed by using Reynolds number and friction factor. It is found that the friction factor decreases with Reynolds number increase in the linear region; while it does not change with Reynolds number in the non-linear region. According to the experimental results, the flow pattern in parallel fractures is developed, and the transformation conditions between two flow patterns are also determined.