Laboratory Investigations of the Hydro-Mechanical–Chemical Coupling Behaviour of Sandstone in CO2 Storage in Aquifers

• Published in: Rock Mechanics and Rock Engineering
• Main Authors: Zhou, Hui, Hu, Dawei, Zhang, Fan, Shao, Jian-Fu, Feng, Xiating
• Other Authors: State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Laboratoire de Mécanique de Lille - FRE 3723 (LML), Université de Lille, Sciences et Technologies-Centrale Lille-Centre National de la Recherche Scientifique (CNRS), Wuhan Polytechnic University, Université de Lille, Sciences et Technologies
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: Hydro-mechanical–chemical coupling CO2–brine–rock reaction Creep test Indentation test; [SPI]Engineering Sciences [physics]; Carbonic acid
• Online Access: https://hal.archives-ouvertes.fr/hal-01277803; https://doi.org/10.1007/s00603-015-0752-8

International audience This paper is devoted to experimental investigations of the hydro-mechanical–chemical coupling behaviour of sandstone in the context of CO2 storage in aquifers. We focused on the evolution of creep strain, the transport properties and the elastic modulus of sandstone under the effect of CO2–brine or CO2 alone. A summary of previous laboratory results is first presented, including mechanical, poromechanical and hydro-mechanical–chemical coupling properties. Tests were then performed to investigate the evolution of the creep strain and permeability during the injection of CO2–brine or CO2 alone. After the injection of CO2–brine or CO2 alone, an instantaneous volumetric dilatancy was observed due to the decrease in the effective confining stress. However, CO2 alone had a significant influence on the creep strain and permeability compared to the small influence of CO2–brine. This phenomenon can be attributed to the acceleration of the CO2–brine–rock reaction by the generation of carbonic acid induced by the dissolution of CO2 into the brine. The original indentation tests on samples after the CO2–brine–rock reaction were also performed and indicated that the elastic modulus decreased with an increasing reaction time. The present laboratory results can advance our knowledge of the hydro-mechanical–chemical coupling behaviour of sandstone in CO2 storage in aquifers.