支撑剂在交叉裂缝中运移规律的数值模拟

Numerical simulation of proppant transport law in intersecting fractures

曾军胜,戴城,方思冬,李恒,刘华

中国石化石油勘探开发研究院，北京 100083 中国地质大学（武汉）资源学院，湖北 武汉 430074

Petroleum Exploration and Development Research Institute, SINOPEC, Beijing 100083, China School of Earth Resources, China University of Geosciences, Wuhan 430074, China

支撑剂运移是水力压裂体系中一个重要的流体￣颗粒两相流问题。如何改善支撑剂在缝网中的铺置情况，是压裂改造后提高储层有效传导率的关键。针对这一问题，结合计算流体力学￣离散元（CFD￣DEM）方法，文中对支撑剂在交叉裂缝中的运移规律进行了数值模拟研究，主要分析了在不同裂缝交角和携砂液黏度条件下支撑剂的运移规律。结果表明：随着裂缝交角增大，支撑剂进入支缝的比例不断下降；提高携砂液黏度，能够改善支撑剂在支缝中的运移情况；在特殊条件下，支撑剂在狭窄支缝中可能出现空间非均匀性的聚团效应。利用CFD￣DEM方法能够准确刻画颗粒与颗粒/壁面及流体与颗粒之间的相互作用。

Proppant transport is a significant fluid-particle two phase flow in hydraulic fracturing system, and how to enhance the efficiency of proppant placement is the key to improving the conductivity of stimulated formations. To solve this issue, in this paper, the CFD-DEM method is adopted to simulate the proppant transport process in intersected fractures, and the proppant placement law under different fracture intersection angles and different sand-carrying fluid viscosity is investigated. The results show that the proportion of proppant transported into secondary fracture monotonically decreases as intersection angle increases, and increasing the fluid viscosity helps improving the placement efficiency of proppant in secondary fractures. Besides, under particular conditions, particle clustering phenomena can occur during transport in a narrow secondary fracture. The CFD-DEM method can accurately describe the particle-particle/wall interactions and fluid-particle interactions.

10.6056/dkyqt202105021