Abstract The effect of fracture roughness is investigated on proppant transport in hydraulic fractures using Joint Roughness Coefficient and a three-dimensional multiphase modelling approach. The equations governing the proppant transport physics in the fracturing fluid is solved using the hybrid computational fluid dynamics model. The reported proppant transport models in the literature are limited to the assumption of a smooth fracture domain with no fluid leak-off or fluid flow from fracture to rock matrix interface. In this paper, a proppant transport model is proposed that accounts for the proppant distribution in rough fracture geometry with fluid leak-off effect to surrounding porous rock. The hydrodynamic and mechanical behaviour of proppant transport was found directly related to the fracture roughness and flow regime especially under the influence of low viscosity fracturing fluid typically used in shale gas reservoirs. For the proppant transport in smooth fractures, the fracture walls employ mechanical retardation effects and reduce the proppant horizontal velocity resulting in more significant proppant deposition. On the contrary, for the proppant transport in rough fractures, the inter-proppant and proppant wall interactions become dominant that adds turbulence to the flow. It results in mechanical interaction flow effects becoming dominant and consequently higher proppants suspended in the slurry and greater horizontal transport velocity. Furthermore, the mechanical interaction flow effects were found to be principally dependant on the proppant transport regime and become significant at higher proppant Reynolds number.

中文翻译：

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裂缝粗糙度对水力裂缝中支撑剂输送流体动力学的影响

摘要 使用联合粗糙度系数和三维多相建模方法研究了裂缝粗糙度对水力裂缝中支撑剂输运的影响。使用混合计算流体动力学模型求解控制压裂液中支撑剂传输物理的方程。文献中报道的支撑剂输运模型仅限于假设一个光滑的裂缝域，没有流体泄漏或流体从裂缝到岩石基质界面的流动。在本文中，提出了一种支撑剂输运模型，该模型考虑了粗糙裂缝几何结构中的支撑剂分布，并具有对周围多孔岩石的流体泄漏效应。发现支撑剂输送的流体动力学和力学行为与裂缝粗糙度和流动状态直接相关，尤其是在页岩气藏中通常使用的低粘度压裂液的影响下。对于光滑裂缝中的支撑剂输运，裂缝壁采用机械阻滞效应并降低支撑剂水平速度，从而导致更显着的支撑剂沉积。相反，对于粗糙裂缝中的支撑剂输运，支撑剂和支撑剂壁之间的相互作用变得占主导地位，从而增加了流动的湍流。它导致机械相互作用流动效应变得占主导地位，因此悬浮在泥浆中的支撑剂更高，水平输送速度更大。此外，