Civil Engineering Departmental Seminar - Low-permeability media and matrix-fracture interactions in the context of carbon neutrality

Low-permeability media and matrix-fracture interactions in the context of carbon neutrality

Deep-earth energy studies involve the efficient exploitation of shale oil and gas, geological storage of carbon dioxide and green hydrogen, geological disposal of high-level nuclear waste, and enhanced geothermal energy utilization, involving rock masses such as sandstone, carbonate rock, shale, salt rock, granite and basalt, and generally has natural fractures or requires artificial fracturing. Nano-petrophysical studies include rock properties, fluid (formation water, liquid hydrocarbons, gas, supercritical CO2) properties, and the interaction between rocks and fluids. In particular, it is necessary to consider the coupled thermal-hydraulic-mechanical-chemical-biological processes of low-permeability rocks with a large number of nano-scale pores and deep-earth environments. The microscopic pore connectivity and matrix-fracture interaction of low-permeability rocks play an important role in controlling macroscopic fluid seepage and mass-heat transfer. This presentation focuses on the dual systems of micro-nano pores and fractures in rock masses, and establishes an independently developed complementary multi-method and multi-scale integration (such as liquid-gas diffusion, hydrophilic-hydrophobic phase nano-sized tracers, and micron-scale laser ablation-ICP-MS tracer element distribution imaging, etc.) for an integrated nano-petrophysical research system. It demonstrates the unique application of large scientific facilities (small-angle neutron and X-ray scattering), conducts innovations in theory (dual-zone pore connectivity) and methods (instrument development and application), and clarifies whether the application of the above-mentioned rock masses in the field of energy geosciences and engineering can help achieve the goals of carbon neutrality.