海洋天然气水合物储层拉削开采新方法及可行性分析

针对深水浅层非成岩天然气水合物借鉴刨煤机刨削采煤过程提出一种新的拉削开采方法，参照拉刀结构特点设计了一种集开采、收集和输送为一体的拉削管。建立了拉削开采三维模型，对其工作原理和工作步骤进行了说明。用有限元仿真对采空区和拉削管受力进行了分析。结果表明，岩土力学仿真下采空区开采半径和开采角度的增大都会引起剪切应力的增加，最大剪切应力发生在采空区上部的起始位置和终止位置；在不发生剪切破坏的采空区中选择体积较大者作为理想采空区，估算出拉削开采方法的日产气量为142000 m3，具有应用潜力；开采工况下，拉削管的最大等效应力小于管材的屈服极限，表明开采过程中拉削管处于弹性形变，满足方法需求。

New broaching exploitation method and feasibility analysis of marine gas hydrate reservoirs

At present, the main methods for extracting natural gas hydrates are thermal extraction, vacuum extraction and chemical reagent extraction. They are mainly used for the development of diagenetic hydrate reservoirs in tight cap rocks, and cannot be used to extract shallow non-diagenetic hydrates that account for 85% of deep water resources. Taking the Shenhu area of the South China Sea as the mining target area, a new type of broaching exploitation method was proposed on the basis of solid-state fluidization theory. A three-dimensional model of broaching exploitation method was established, the working principle, working steps and stope distribution of the new technology were explained in detail, and a broaching tube was designed for broaching, collecting and transportation mining tools. Use the knowledge of geotechnical mechanics to analyze the shear stress of the goaf produced by the broaching exploitation method can ensure that the goaf does not collapse and obtain the maximum stope volume. The force analysis of the broached pipe according to the mining conditions ensured that the broached pipe can work safely and stably. Finally, the daily gas production of the broaching technology was estimated. The results showed that the larger the goaf radius and the mining angle were, the more obvious the shear stress concentration in the goaf. The maximum shear stress occurred at the start and end positions of the upper part of the goaf. The maximum stress of the broaching tube during the mining process was less than the yield stress of the material. The daily gas output of the broaching technology was estimated to be 142000 m3, which had practical application potential.