Tensile Behavior and Fracture Process Zone in Utah FORGE Hot Dry Rock: A 3D-DIC Investigation

ABSTRACT: Geothermal energy is a sustainable, low-emission alternative to conventional energy sources, with Enhanced Geothermal Systems (EGS) expanding its accessibility by artificially creating geothermal reservoirs in impermeable hot dry rock (HDR) formations. While EGS improves fluid circulation and heat extraction, challenges such as maintaining fracture connectivity and preventing heat and fluid loss hinder efficiency and economic viability. This study examines the tensile behavior and fracture process zone (FPZ) in HDR samples from the Utah FORGE site using 3D Digital Image Correlation (3D-DIC) under standard laboratory conditions with a slightly elevated sample temperature. Through quasi-static mechanical testing, strain fields and fracture propagation are analyzed to characterize fracture development. The findings are expected to offer valuable insights into EGS-induced fracturing for HDR development, advancing geomechanical understanding through experimental analysis and advanced modeling techniques.