Stimuli-Responsive/Rheoreversible Hydraulic Fracturing Fluids for Enhanced Geothermal Systems

Abstract

Cost-effective and safe creation of high-permeability reservoirs inside deep crystalline bedrock is the primary challenge for the application of enhanced geothermal systems (EGS). Current reservoir stimulation processes entail adverse environmental impacts and substantial economic costs due to the utilization of extremely large volumes of water and a concomitant high amount of chemicals which can potentially contaminate deep aquifers. In this work, we report an environmentally benign, CO2-activated, rheoreversible fracturing fluid that significantly enhances rock permeability at effective stress orders of magnitude lower than current technology. This novel hydraulic fracturing technique dramatically reduces water usage and the environmental impact of fracturing practices, potentially making geothermal energy production cost-effective and cleaner.