Time-dependent behaviors of methane-hydrate bearing sediments in triaxial compression test
Natural gas hydrate, existing in marine sediments worldwide and in permafrost regions, is anticipated to be a promising energy resource. It is essential to consider the mechanical properties, including their time dependence, of a gas hydrate reservoir to simulate the geomechanical response to gas ex...
| Main Authors: | , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Japanese Committee for Rock Mechanics
2011
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| Subjects: | |
| Online Access: | https://oceanrep.geomar.de/id/eprint/43069/ https://oceanrep.geomar.de/id/eprint/43069/1/7_43.pdf https://doi.org/10.11187/ijjcrm.7.43 |
| Summary: | Natural gas hydrate, existing in marine sediments worldwide and in permafrost regions, is anticipated to be a promising energy resource. It is essential to consider the mechanical properties, including their time dependence, of a gas hydrate reservoir to simulate the geomechanical response to gas extraction from a reservoir. Recently it has been revealed that gas-hydrate-bearing sediments have rocklike mechanical characteristics due to the cementation effect of the hydrate between soil particles. To obtain information about the time dependence of gas-hydrate-bearing sediments, experimental methods for drained triaxial compression tests including a procedure for the preparation of artificial methane-hydrate-bearing sediment specimens have been established. Using these methods, constant-strain-rate tests and creep tests on artificial methane-hydrate-bearing sediment specimens have been conducted. In this report, the methods and results of the tests are presented, and the time-dependent behaviors of methane-hydrate-bearing sediment are discussed. On the basis of the results, the strain-rate dependence of the peak strength was examined, and it was found that the time dependence of the artificial methane-hydrate-bearing sediment is as strong as that of frozen sand and stronger than that of many other geological materials. It was also found that the creep deformation of methane-hydrate-bearing sediment is much larger than that of water-saturated sand without the hydrate. The experimental data presented in this report are expected to be used to obtain a full understanding of the deformation mechanism of methane-hydrate-bearing sediments and to formulate a constitutive equation for methane-hydrate-bearing sediments in future studies. |
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