Underground hydrogen storage (UHS) in porous reservoirs requires laboratory constraints on flow, electrical, and elastic properties under in situ conditions. However, these properties are commonly measured separately, which hampers consistent interpretation across reservoir simulation and geophysical monitoring. We developed a System for Experimental PetroPhysics (SEPP) that performs concurrent hydraulic, four-electrode resistivity, and ultrasonic measurements on a single core during single and two-phase flow at reservoir pressure and temperature. The system was benchmarked on Bentheimer sandstone at 37 °C, 150 bar confining pressure, and 10-120 bar pore pressure using brine and hydrogen. Absolute permeability increased by approximately 8% as effective stress decreased over the tested pressure range, whereas bulk resistivity increased by approximately 1.9% with increasing effective stress. During H 2 -brine drainage, brine relative permeability decreased strongly with brine saturation, while hydrogen relative permeability remained low (10 -3 -10 -2 ), consistent with limited gas connectivity at high brine saturation. Bulk resistivity followed Archie-type behavior with n = 1.786, enabling time-resolved saturation estimation, and P-wave velocity decreased from approximately 4.1 to 3.8 km/s with decreasing brine saturation, whereas S-wave velocity remained nearly constant at approximately 2.8 km/s. Joint interpretation of hydraulic, electrical, and ultrasonic data with established models supports pressure-aware saturation retrieval, stress-dependent permeability estimation, and discrimination between homogeneous and patchy fluid distributions. The benchmark results demonstrate that concurrent measurements on a single core could provide a consistent basis for parameterizing reservoir simulators and calibrating geophysical monitoring workflows for UHS and related subsurface storage applications.
David et al. (Mon,) studied this question.