Microscopic numerical modeling of Thermo-Hydro-Mechanical mechanisms in fluid injection process in unconsolidated formation

摘要: Abstract The temperature difference between injected fluid and surrounding rock can play an important role in the initiation propagation of fractures completion simulation operations. In this work, thermal effect is investigated using DEM-based micromechanics model implemented Particle Flow Code (PFC). mass represented by assembly discrete particles that are bonded at contacts. developed thermo-hydro-mechanical (THM) module, heat conduction across solids matrix convection solid coupled. evolution system driven a continuous point source heat. Simulation results show more cracks tend to be generated anisotropic conductivity, induced stress, distribution pore pressure predicted consistent with laboratory observations from conventional continuum mechanics models. Furthermore, Fracability Index introduced for evaluating fracturing performance, comparison hydro-injection hydro-thermal injection (heating cooling). This study indicates stresses greatly affect assist communication formation; considered as effective method connect fracture network, enhance weak zones create fractures.