INTRODUCTION AND APPLICATION OF HYDRO-MECHANICAL UNITED EXPERIMENT APPARATUS FOR HYDRATE-BEARING SEDIMENTS

The exploitation of methane hydrate from seafloor could degrade the strength properties of the reservoir,and further induce the geological disasters,threatening safety of the drilling platform and the exploitation well. This paper aims to explore the mechanical properties of hydrate-bearing sediments and reveal the mechanism of mechanical strength deterioration of hydrate reservoirs induced by hydrate exploitation. It develops a set of hydraulic-mechanical united experiment apparatus for hydrate-bearing sediment. This apparatus consists of the pressure chamber,pressure-control system,supply/exhaust gas system,temperature control system,data acquisition and human-computer interaction management system. Based on these components,this apparatus can be used to synthesize the methane hydrate-bearing sediment sample,and perform the permeability measurement test,the isotropic compression test and the triaxial compression test under different stress paths. For illustrating the functions of this apparatus,methane hydrate-bearing fine sand specimens are prepared by excess-gas method. The hydraulic-mechanical characteristics are measured. The experimental results are analyzed briefly,and confirm the function and reliability of the apparatus for measuring the hydro-mechanical properties of hydrate bearing sediments.