This paper investigates the dynamics of proppant agglomerations during flow and transport within fractures intersected at the angles typical for the joint of pre-existing and newly formed fractures. The study considers variations and coupling of fluid flow rates, proppant volumetric concentrations, fluid dynamic viscosities and fracture intersection angles. Proppants are widely used during hydraulic fracturing to keep fractures open and enhance reservoir permeability. This study uses plexiglas experimental slots and visual analysis for identifying particle displacements. Geo-Particle Image Velocimetry–Reliability-Guided (GeoPIV-RG) method tracks particle movements among images by comparing the reference and subsequent snapshots at the point and time of interest. Results of this study show that the proppant volumetric concentration and the fluid flow rate are closely correlated with each other for affecting proppant flow, transport, and agglomeration formation. Increasing the proppant volumetric concentration generally promotes particle agglomeration, with different extent when coupled with the fluid flow rate. Proppant volumetric concentration affects the size, shape, and distribution of particle clusters. Increasing the fluid flow rate increases the occurrence of particle agglomerates at low proppant volumetric concentration; however, this trend is absent under high proppant volumetric concentrations. Sizes and shapes of proppant agglomerates change as the fluid flow rate changes. Changes of fracture intersection angle minimally affect shape, size and distance between proppant agglomerates and clusters. Furthermore, increasing the fluid dynamic viscosity strongly promotes proppant agglomeration. Although fluid dynamic viscosity changes do not affect the shape and size of particle clusters, the distance between adjacent clusters decreases at higher fluid dynamic viscosity.

本文研究了在裂缝内流动和输送过程中支撑剂团聚的动力学过程，这些裂缝以典型的既有裂缝和新形成裂缝的连接点相交的角度相交。该研究考虑了流体流速，支撑剂体积浓度，流体动态粘度和裂缝相交角的变化和耦合。在水力压裂期间，支撑剂被广泛使用，以保持裂缝张开并提高储层渗透率。这项研究使用有机玻璃实验槽和视觉分析来识别颗粒位移。地理粒子图像测速－可靠性指导（GeoPIV-RG）方法通过比较感兴趣的点和时间处的参考快照和后续快照来跟踪图像之间的粒子运动。这项研究的结果表明，支撑剂的体积浓度和流体流速彼此之间密切相关，从而影响支撑剂的流动，运输和结块的形成。当与流体流速结合时，增加支撑剂体积浓度通常会促进颗粒附聚，其程度不同。支撑剂的体积浓度会影响粒子簇的大小，形状和分布。在低支撑剂体积浓度下，增加流体流速会增加颗粒团聚的发生。然而，在高支撑剂体积浓度下这种趋势是不存在的。支撑剂附聚物的尺寸和形状随着流体流速的变化而变化。裂缝相交角的变化对支撑剂团聚体和团簇之间的形状，大小和距离的影响最小。此外，增加流体动力粘度强烈促进支撑剂附聚。尽管流体动力粘度的变化不会影响颗粒团的形状和大小，但是在更高的流体动力粘度下，相邻团之间的距离会减小。