Impact of CO2-Exposure on the Mechanical and Microstructural Properties of Glauconitic Sandstones

Abstract

In recent years, the urgency of addressing global warming has intensified, driving the development of carbon capture and storage (CCS) technologies as a critical strategy for mitigating greenhouse gas emissions. This study focuses on evaluating the feasibility of implementing CO2 storage within a glauconitic sandstone from the Golfo San Jorge Basin (Patagonian Region, Argentina). To achieve this aim, the evolution of the mechanical, microstructural and compositional behavior of the rock when exposed to a CO2 rich environment, is examined using samples obtained from outcrop. A series of uniaxial and triaxial compressive tests were performed on pristine and CO2-aged specimens to evaluate changes in mechanical properties. Complementary analysis including mercury intrusion porosimetry (MIP), X-ray fluorescence (XRF), and X-ray diffraction (XRD) provided insight into the alterations in porosity and mineralogical composition caused by the CO2 interaction. The preliminary findings suggest changes in the mechanical properties of sandstone after exposure to CO2, such as a notable reduction in mechanical strength. Changes in porosity and mineralogical composition have also been observed, primarily within the CO2 contact zone.