Natural gas hydrates (NGHs) have attracted considerable attention due to their abundant reserves, widespread distribution, and high energy density. Successful commercial extraction of NGHs could lead to a significant reduction in coal and oil consumption, ultimately mitigating the greenhouse effect and ameliorating global environmental problems. Despite over ten global hydrate pilot productions, there is currently no universally accepted classification system or international standard for naturally occurring NGH resources within the industry. This work highlights the importance of classifying NGH resources in order to initiate their exploitation. In this review, we summarize and evaluate various studies conducted on the classification of NGH resources and thoroughly analyze the potential applications of these classification systems. While non-quantitative observations and analyses predominate, the exploitation of specific technological breakthroughs will rely on quantitative reservoir descriptions. The applicable extraction methods for different types of NGH reservoirs and the challenges faced during the exploitation process were discussed. A thorough analysis of future directions in NGH classification research was presented, and this review suggests that the exploitation trend lies in the combination of NGH resource classification and various hydrate exploitation technologies. Priority should be given to the exploitation of NGH reservoirs with better reservoir conditions, higher yields, and lower risks.

中文翻译：

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天然气水合物资源分类：回顾、应用与展望

天然气水合物（NGH）因其储量丰富、分布广泛、能量密度高而受到广泛关注。水合物的成功商业开采可以显着减少煤炭和石油消耗，最终减轻温室效应并改善全球环境问题。尽管全球有十多个水合物试点生产，但目前业内还没有普遍接受的天然水合物资源分类系统或国际标准。这项工作强调了对水合物资源进行分类以启动其开发的重要性。在这篇综述中，我们总结和评估了关于水合物资源分类的各种研究，并深入分析了这些分类系统的潜在应用。虽然非定量观察和分析占主导地位，但具体技术突破的开发将依赖于定量储层描述。讨论了不同类型水合物储层适用的开采方法以及开采过程中面临的挑战。对水合物分类研究未来的发展方向进行了深入分析，认为水合物资源分类与多种水合物开采技术相结合是未来的开发趋势。优先开发储层条件较好、产量较高、风险较低的水合物藏。