Abstract Natural gas hydrate is an attractive potential as alternative energy source. The initial studies of natural gas hydrate production test have shown that the hydrate productivity via conventional depressurization is still far to reach the commercial level, hence, hydraulic fracturing has been proposed to stimulate the hydrated formation to enhance production. However, the buried depth of hydrate-bearing sediments is generally shallow, and the cementation of sediments is weak. Whether the hydrate-bearing sediments has adequate and commercially viable fracability is a question yet to be answered. In this study, a novel feasibility evaluation model of hydraulic fracturing in hydrate-bearing sediments is developed based on analytic hierarchy process-entropy method. The fracability index is proposed to evaluate the fracability of hydrate-bearing sediments. Representative samples were built based on the physical and mechanical characteristics of Alaska permafrost, and hydraulic fracturing experiments were carried out to evaluate the feasibility of hydraulic fracturing as a stimulation technique. The results showed that the hydrate-bearing sediments with fracability index >0.72 can form fractures under different fracturing fluid viscosity ratio. For hydrate-bearing sediments with fracability index

中文翻译：

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基于层次分析法-熵值法(AHP-EM)的含水合物沉积物水力压裂可行性评价

摘要 天然气水合物作为替代能源具有极具吸引力的潜力。天然气水合物生产试验的初步研究表明，常规降压的水合物产能仍远未达到商业水平，因此提出水力压裂以刺激水合物地层增产。但含水合物沉积物埋藏深度普遍较浅，沉积物胶结作用较弱。含水合物沉积物是否具有足够的商业上可行的可压裂性是一个有待回答的问题。本研究基于层次分析法-熵值法，建立了含水合物沉积物水力压裂可行性评价模型。提出了可压裂性指数来评价含水合物沉积物的可压裂性。根据阿拉斯加永久冻土的物理和力学特性，建立了代表性样品，并进行了水力压裂实验，以评估水力压裂作为增产技术的可行性。结果表明，可压裂性指数>0.72的含水合物沉积物在不同压裂液粘度比下均能形成裂缝。对于具有可压裂性指数的含水合物沉积物 结果表明，可压裂性指数>0.72的含水合物沉积物在不同压裂液粘度比下均能形成裂缝。对于具有可压裂性指数的含水合物沉积物 结果表明，可压裂性指数>0.72的含水合物沉积物在不同压裂液粘度比下均能形成裂缝。对于具有可压裂性指数的含水合物沉积物