酸性水-岩作用下花岗岩孔隙结构与热-力学性能劣化机理的实验研究OA

Water-rock interaction(WRI)during Hot Dry Rock(HDR)exploitation is a critical factor affecting the long-term stability of geothermal reservoirs.To address the challenge that conventional experimental methods struggle to simultaneously simulate long-term effects while preserving sample integrity,this study introduces a self-developed high-temperature and high-pressure WRI simulation device.Using an acidic solution as an accelerating medium,dynamic interaction experiments on granite samples were conducted for 3,6,and 9 days.Through a combination of nuclear magnetic resonance,thermal conductivity analysis,and mechanical testing,this research systematically reveals the synergistic degradation mechanism of the granite's pore structure and thermo-mechanical properties under acidic conditions.The results demonstrate that acidic WRI leads to a non-linear and dramatic increase in granite porosity(by 448%within 9 days),with a shift in pore size distribution from predominantly micropores to a higher proportion of meso-and macropores.The deterioration of the pore structure induces a significant decline in thermal conductivity and uniaxial compressive strength,which decrease by 8.63%and 33.19%,respectively,over the same 9-day period,showing highly consistent evolutionary trends.This study successfully establishes a quantitative link between short-term accelerated laboratory simulations and long-term in-situ evolutionary behavior,providing crucial experimental data and theoretical support for accurately predicting the physical-mechanical behavior of HDR reservoirs during their service life,assessing their long-term stability,and ultimately ensuring the safe and efficient development of geothermal resources.