Indexed by:Journal Article

Date of Publication:2013-05-24

Journal:Applied Mechanics and Materials

Included Journals:Scopus、CPCI-S、EI

Volume:353-354

Page Number:1240-1244

ISSN:9783037857755

Key Words:CH4-CO2 Replacement; Carbon Dioxide Storage; Hydrate; Triaxial Compression; Strength

Abstract:The CH4-CO2 replacement method to recover CH4 from hydrate-bearing sediments has received great attention because it enables the long term storage of CO2 and is expected to maintain the stability of gas hydrate-bearing sediments. This paper extends our previous study of the stability of CH4 hydrate-bearing sediments to CO2 hydrate-bearing sediments to evaluate the safety of the CH4-CO2 replacement method. Low temperature, high pressure triaxial compression apparatus was used to measure the mechanical properties of CO2 hydrate-bearing sediments. The triaxial tests results for CH4 and CO2 hydrate-bearing sediments were then compared. It was found that the failure mode of both the CO2 and CH4 hydrate-bearing sediments was a bulging deformation at mid-height on the samples. Moreover, the stress-strain curves of both the CO2 and CH4 hydrate-bearing sediments appear to be hyperbolic in shape, and could be divided into three stages: the quasi-elastic stage, the hardening stage and the yield stage. However, the strength of the CO2 hydrate-bearing sediments was approximately 15% larger than that of the CH4 hydrate-bearing sediments under the same conditions. The results imply that the stability of gas hydrate-bearing sediments could be maintained using the CH4-CO2 replacement method to recover CH4 from these sediments.