Experiment and simulation of slurry flow in irregular channels to understand proppant transport in complex fractures--颗粒学报PARTICUOLOGY

Qu, H., Hong, J., Liu, Y., Zeng, Z., Liu, X., Chen, X., & Guo, R. (2023). Experiment and simulation of slurry flow in irregular channels to understand proppant transport in complex fractures. Particuology, 83, 194-211. https://doi.org/10.1016/j.partic.2023.05.010

Experiment and simulation of slurry flow in irregular channels to understand proppant transport in complex fractures

Hai Qu ^a *, Jun Hong ^a, Ying Liu ^a, Zhijun Zeng ^a *, Xu Liu ^a, Xiangjun Chen ^a, Ruichang Guo ^b

a Chongqing University of Science and Technology, Chongqing, 401331, China
b Department of Mining and Minerals Engineering, Virginia Tech, Blacksburg, VA, 24061, USA

10.1016/j.partic.2023.05.010

Volume 83, December 2023, Pages 194-211

Received 15 March 2023, Revised 6 May 2023, Accepted 26 May 2023, Available online 12 June 2023, Version of Record 22 June 2023.

E-mail: quhai729@163.com; 2382547980@qq.com

Highlights

• High-concentration slurry flow in complex fractures was investigated.

• Sand-slickwater flow experiment was conducted in irregular channels.

• The improved CFD-DEM method can describe interactions of particle and wall.

• A dimensionless model was developed to predict the coverage ratio of proppant dune.

Abstract

Slurry flow and proppant placement in irregular fractures are crucial to evaluate hydraulic fracturing stimulation but need to be better understood. This study aims to investigate how irregular fracture affects proppant transport and distribution using laboratory experiments and micro-scale numerical models. The unresolved method of the computational fluid dynamics (CFD) and the discrete element method (DEM) considers Saffman lift force, Magnus force, and virtual mass force to accurately capture the frequent interaction between proppant and slickwater. Experimental results validated the reliability of the optimized CFD-DEM model and calibrated primary parameters. The effects of crack height and width, bending angle, and distance between the crack and inlet on particle distribution were studied. The results indicated that the improved numerical method could rationally simulate proppant transport in fractures at a scale factor. The small crack height causes downward and upward flows, which wash proppant to the fracture rear and form isolated proppant dunes. A wider region in the fracture is beneficial to build up a large dune, and the high dune can hinder particle transport into the fracture rear. When the crack is close to the inlet, the primary fracture without proppants will close to hinder gas production. The smaller the bending angle, the smaller the proppant dune. A regression model can precisely predict the dune coverage ratio. The results fundamentally understand how complex fractures and natural cracks affect slurry flow and proppant distribution.

Graphical abstract

Keywords

Slurry flow; Sand transport; Particle-fluid interaction; Irregular channel; CFD-DEM

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