Abstract
How does CO₂ injection alter pore structure, permeability, and long-term reservoir integrity? Do sandstones and carbonates respond in fundamentally different ways under storage conditions?
This talk examines CO₂–brine–rock interactions in two contrasting lithologies: Entrada Sandstone and the San Andres carbonate. High-pressure, high-temperature experimental testing on Entrada Sandstone reveals carbonate cement dissolution, silicate alteration, fines migration, and measurable permeability evolution under reservoir conditions. Integrated SEM-EDS, XRD, and ICP analyses demonstrate dynamic dissolution–precipitation processes that restructure pore networks and influence injectivity. Complementary reactive transport simulations in the San Andres carbonate highlight spatially heterogeneous behavior, including near-wellbore precipitation with minor permeability reduction and distal dissolution-driven porosity enhancement.
Bio
Dr. Hamid Rahnema is an Associate Professor and Chair of the Petroleum Engineering Department at New Mexico Tech. He holds a BSc in Petroleum Engineering from the Petroleum University of Technology in Iran, an MSc in Geoscience Engineering from IFP School in France, and a PhD in Petroleum Engineering from Texas A&M University. Before joining New Mexico Tech in 2012, Dr. Rahnema worked as a Senior EOR Engineer with SGS North America in Woodland, Texas. An active member of the Society of Petroleum Engineers (SPE) for 23 years, he currently chairs the SPE Roswell Section's program committee.
Dr. Rahnema’s research interests center on multiphase flow in porous media, subsurface geochemistry, and phase behavior. His research group is engaged in several projects, including studies on geologic hydrogen production, shallow geothermal systems, and subsurface storage integrity. Dr. Rahnema is involved as PI/Co-PI/KP in several projects sponsored by the DOE as well as in various industrial projects.