Abstract:Deep sea energy soil refers to sea bed sediments containing new strategic energy-natural gas hydrate. Depressurization is a relatively economical and efficient way to exploit gas hydrate, the determination of the decomposition zone of hydrate reservoir and the stability analysis of energy soil slope are one of the preconditions to ensure the safe and effective exploitation of gas hydrate. In this paper, the basic equations of hydrate depressurization mining were summarized firstly. The determination of decomposition area of submarine slope hydrate reservoir under the condition of depressurization mining was realized in ABAQUS software by programming the USDFLD subroutine, and the variation of hydrate saturation and related physical property parameters was simulated. Combining with an actual deep sea energy soil slope, the decomposition area, the effective stress and deformation field of the energy soil slope under the condition of depressurization was calculated, and the actual condition of the deep sea energy soil slope was simulated by the finite element strength reduction method. The results show that the safety factor changes little before and after mining, and the effect of single well depressurization mining on slope stability is not obvious.