Compression and Flow Behavior of Proppants in Hydraulically Induced Fracture

Abstract

Short-term and long-term compression behavior of single proppant grains were thoroughly studied by diametrical compression tests and DEM/FEM simulations. Hydroprop showed the highest single grain crush-resistance while ceramic proppant grains with coarse surfaces were susceptible to creep behavior under load. One-dimensional compression tests under various stress levels and temporal conditions were systematically carried out to investigate the time-independent and time-dependent crushing behavior of proppant grain packs. Baylic Sand was the most crushing-prone whereas the OxSteel was the least. Most proppants showed creep behavior under long-term compression. Rock-proppant interaction tests were also performed which cast light on the proppant crushing and embedment under the field conditions. Pressure gradients of proppant-water slurries flowing through a small-diameter pipe were experimentally investigated and mimicked by DEM-CFD simulations. A generalized Darcy-Weisbach equation was proposed for the prediction of pressure gradients.