Experimental flow-through a single fracture with monolayer proppant at reservoir conditions: A case study on Caney Shale, Southwest Oklahoma, USA

Global energy systems are undergoing a crucial transition to clean energy sources, thereby moving away from fossil-fuel based energy with the ultimate aim of reducing carbon dioxide emissions. It is essential to continue to advance in exploring and developing shale gas resources as this will underpin the global supply of natural gas that is needed to support the energy transition. The challenge hereby is that the slow fluid flow of the shale matrix due to its very low permeability requires large-scale volume fracturing to produce a conductive fracture network that enhances the connectivity between the shale formation and the wellbore. This work examines the influence of a thin proppant layer on a single fracture using a flow-through experiment, and also explores whether proppant embedment in the Caney shale is affected by the rock mineralogy, surface roughness, fluids, confining stress, time, temperature and bedding. The experiment was conducted for a duration of nine days (216 h), experimental temperature was varied from ambient temperature to reservoir temperature of 125 degrees C (257 degrees F) and confining stress was varied from 367 psi (2.53MPa) to a maximum of 4011.82 psi (27.66 MPa). We find that the conductivity of the fracture is primarily influenced by the layer of proppant used, surface roughness, mineralogy, fluids, temperature and closure stress.

Automated summary

Global energy systems are transitioning to clean energy sources to reduce carbon dioxide emissions, necessitating the exploration and development of shale gas resources to support the global supply of natural gas. The challenge lies in the low permeability of shale, requiring large-scale volume fracturing to enhance connectivity. This study investigates the influence of a thin proppant layer on a single fracture and explores the effects of rock mineralogy, surface roughness, fluids, confining stress, time, temperature, and bedding on proppant embedment in Caney shale. The experiment revealed that fracture conductivity is primarily affected by proppant layer, roughness, mineralogy, fluids, temperature, and closure stress.