Indexed by:Journal Article

Date of Publication:2013-09-01

Journal:JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING

Included Journals:Scopus、EI、SCIE

Volume:109

Page Number:45-50

ISSN:0920-4105

Key Words:gas hydrate; strength criterion; constitutive model; triaxial compression tests

Abstract:Mechanical properties of gas hydrate-bearing sediments are important for the safe production of natural gas from hydrate reservoirs, as well as conventional oil or gas beneath the gas hydrate bearing sediments. In order to determine the failure load and describe the deformation behavior of gas hydrate-bearing sediments in deepwater regions, a series of triaxial compression tests on synthetic gas hydrate-bearing sediment cores were conducted under high confining pressures and a temperature of -10 degrees C. The results verify that the deviator stress increases gradually with increasing axial strain and finally reaches a constant value without significant peak value. When confining pressure >= 5 MPa, the failure strength decreases with increasing confining pressure because of particle crushing and pressure melting of ice. A new strength criterion to well reflect the failure load of gas hydrate-bearing sediments under high confining pressures is proposed based on the experimental results. The Duncan-Chang model is used to describe the deformation behavior of gas hydrate-bearing sediments under various confining pressures, and it is found that the results predicted by the model agree well with the experimental data. (C) 2013 Elsevier B.V. All rights reserved.