2015 Volume 7 Issue 4 Pages 218-228
Methane hydrate (MH) is considered to be part of a new generation of energy resources. Depressurization has been proposed as a method of extracting methane gas from MH in marine sediments. During depressurization, sediment deformation may occur because of MH dissociation and increased effective stress. It is therefore important to develop long-term, safe methods for protecting equipment used on the sea floor against the impact of deformation. We have developed the “COTHMA” geo-mechanical simulator to predict sediment deformation during methane gas production from MH. We have also performed laboratory experiments (push-out tests) of well integrity to determine model parameters. Deformation and stress in the vicinity of a production well were evaluated to assess the integrity of the well. Our technologies for evaluating sedimentary characteristics consist of the development of the geo-mechanical simulator and the evaluation of well integrity and wide-area deformation. Based on this research, we are now preparing technologies for practical application.
