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Indexed by:期刊论文

Date of Publication:2013-09-01

Journal:MARINE AND PETROLEUM GEOLOGY

Included Journals:SCIE、EI、Scopus

Volume:46

Page Number:201-209

ISSN No.:0264-8172

Key Words:CH4-CO2 replacement; Carbon dioxide storage; Hydrate-bearing sediments; Mechanical properties; Strength

Abstract:The CH4-CO2 replacement method to recover methane 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. In this paper, the mechanical properties of CO2 hydrate-bearing sediments were measured by a low-temperature and high-pressure triaxial compression apparatus. The strength differences between the CO2 and CH4 hydrate-bearing sediments were then analyzed to evaluate the safety of the CH4-CO2 replacement method. The strength of the CO2 hydrate-bearing sediments was found to increase as the temperature and porosity decreased and as the strain rate increased. When the confining pressure was less than 5 MPa, the strength of the CO2 hydrate-bearing sediments also increased as the confining pressure increased. However, owing to pore-ice melting and particle breakage, the strength of the CO2 hydrate-bearing sediments decreased as the confining pressure increased for confining pressures exceeding 5 MPa. The strength of the CO2 hydrate-bearing sediments was found to be larger than that of the CH4 hydrate-bearing sediments, with the strengths of the CH4 and CO2 hydrate-bearing sediments varying with the influence factors in a nearly identical fashion. The results indicate that the stability of gas hydrate-bearing sediments could be maintained using the CH4-CO2 replacement method to recover methane from these sediments. (C) 2013 Elsevier Ltd. All rights reserved.