Experimental and Visual Analysis of Proppant-Slickwater Flow in a Large-Scaled Rough Fracture

作者：Hai Qu, Yang Xu, Jun Hong, Xiangjun Chen, Chengying Li, Xu Liu · 发表于：SPE Journal · 年份：2022 · DOI：10.2118/212283-pa · 被引用次数：34 · 研究领域：Hydraulic Fracturing and Reservoir Analysis、Groundwater flow and contamination studies、Drilling and Well Engineering

Summary Understanding proppant transport and distribution in hydraulic fractures is crucial to designing and optimizing hydraulic fracturing treatments in the field. The actual fracture surfaces are typically rough and form a tortuous pathway, significantly affecting proppant migration. However, many rough models are very small in size, and some have only one rough surface. Thus, it is inadequate to display proppant transport behaviors and placement laws. This study proposed a novel method to develop large-scale rough panels reproduced from actual hydraulic fractures. A large transparent slot (2×0.3 m) was successfully constructed to simulate a shear fracture with 5 mm relative displacement of two matched surfaces. Six kinds of proppants were selected to study the effects of particle density and size. Four types of slickwater were prepared to achieve viscous diversity. A high-resolution particle image velocimetry (PIV) system detected the instantaneous velocity and vector fields in the rough pathway to understand particle transport behaviors. The specific parametric study includes a quantitative analysis of the proppant bed profile, equilibrium height, coverage area, injection pressure, and volumes of proppant settled in the slot and outlet tank. Also, five tests are carried out in the smooth slot, which has the same size as the rough slot. The test results demonstrate that the narrow rough fracture would significantly hinder particle transport, especially in the horizontal d...