Speaker
Description
Geological sequestration of CO2 has emerged as a promising and viable strategy to mitigate climate change by injecting supercritical CO2 (scCO2) into deep subsurface formations for long-term containment. This process can induce salt precipitation, a phenomenon where dissolved salts crystallize out of pore brine. Such precipitation poses significant challenges, including pore blockage, reduced rock strength, and a potential contribution to microseismicity that may compromise reservoir stability. In this study, the effects of salt precipitation on the microstructure and failure characteristics of reservoir rocks were experimentally investigated under reservoir-representative conditions. Results indicate that while salt crystallization densifies the rock's pore structure, it paradoxically undermines the overall mechanical integrity. Specifically, the load-bearing capacity is significantly reduced, making the rock increasingly prone to tensile failure as opposed to shear failure under compressive stress. Given that fluid injection most commonly induces shear failure, particularly in the presence of pre-existing faults, a shift toward tensile-dominated failure makes reservoir damage more complex. Moreover, tensile failure promotes fracture opening and propagation, thereby increasing uncertainty in CO2 migration prediction and monitoring. This transition in failure mode is attributed to weak interfacial bonding between the salt crystals and the rock matrix, along with an increased development of microcracks. These findings provide critical insights into the stability of geological reservoirs during CO2 sequestration and establish a scientific basis for investigating the mechanisms of injection-induced microseismicity.
| Country | China |
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| Student Awards | I would like to submit this presentation into the Earth Energy Science (EES) and Capillarity Student Poster Awards. |
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