Leonardo Guimaraes

Federal University of Pernambuco

Thermo-chemo-mechanical effects at reservoir and near-well scales resulting from acid and CO₂ injection

Thermo-chemo-mechanical phenomena induced by acid/CO₂ injection are strongly coupled processes that require advanced simulation strategies. These involve mass and energy balances in deformable porous media and demand the interaction of flow and thermal simulator, operating within the reservoir subdomain, with a geomechanical (and optionally heat conduction) simulator acting on the full domain, including adjacent rocks. Fully coupled solutions are often computationally prohibitive, leading the industry to adopt spatially coupled approaches integrating specialized simulators. These schemes are crucial to capture complex behaviors such as near-well rock dissolution caused by acidizing or CO₂ injection, potentially resulting in fracturing or pore collapse (during and after injection, respectively). For CO₂ injection into depleted gas reservoirs, Joule–Thomson cooling may occur, generating thermally induced stresses that can fracture the rock. These coupled phenomena are highly relevant to the oil and gas sector and pose significant challenges for safe and effective geological CO₂ storage.