Advanced mechanical testing of gas hydrate-bearing sediments

The understanding of thermo-hydro-chemo-mechanical coupling of dynamic processes, which occur in marine gas hydrate-bearing sediments during natural gas production or slope destabilization, is limited. Recent developments in geotechnical testing offer new approaches to closely simulate sub-marine in-situ conditions, and to generate benchmark tests for numerical model development. Especially when applied in combination with tomographic techniques (e.g. X-ray CT or ERT), high-pressure flow-through triaxial testing could answer important questions related to multi-scale effects, influence of spatial heterogeneities and process dynamics on the stress-strain behavior of gas hydrate-bearing sediments. Based on experimental studies on heterogeneous gas hydrate formation from two-phase fluid flow, we demonstrate the need for advanced mechanical testing. Further, we present the setup of advanced geotechnical test systems combined with X-ray CT or ERT analysis, as well as preliminary results from flow-through triaxial testing with the novel systems.