中文摘要：

本文通过对国外海域天然气水合物钻探的调研，选取布莱克海台、水合物脊、墨西哥湾、日本南海海槽、韩国郁龙盆地、印度大陆边缘等区域，从水合物站位选择目的和站位选择依据这两个方面进行归纳总结和系统对比。研究指出，根据水合物的实际产出和赋存，可将其划分为两大类型：赋存于海底浅表层的水合物（一般在海底之下100m范围内）和赋存于海底之下中一深层的水合物（一般在海底之下100～400m范围内）。前者的主要识别依据为海水异常、含气流体运移通道和异常地形地貌特征，而后者的主要识别依据为地球物理异常反射特征、含气流体运移通道和有利沉积体。因此，如果将水合物的形成、聚集和分布比喻为一个有机的整体，那么“运”和“聚”就构成了这个系统的“骨骼”和“血液”，它们将控制远景区内的水合物分布。将“水合物识别标志”、“有利沉积体展布”和“流体运移通道”三者有机地结合在一起，可以达到更准确地预测和描述水合物矿体的目的，这是今后海域水合物钻探站位选择依据的主要发展方向。

英文摘要：

In order to better understanding the progresses of marine gas hydrate explorations, this study summarized the hydrate drill site objectives and drill site selections through some analyses on Blake Ridge, Hydrate Ridge, Gulf of Mexico, Nankai Trough, Ulleung Basin, and Indian continental margin. According to the actual occurrences, marine gas hydrates might be classified as two types, hydrates in the shallow layers near seafloor （generally within the range of 100 m below the seafloor）, and hydrates in the relatively deep sediments （generally within the range of 100 - 400 m below the seafloor）. The main indicators for site selection of hydrates in the shallow layers are anomalies in seawater, migrations of gas-bearing fluids and specific seafloor topographic features. On the contrast, the main indicators for site selection of hydrates in the deep layers are geophysical anomalies, migrations of gas-bearing fluids and distributions of favorable sediments. Therefore, for the marine gas hydrates system, fluids migrations and potential reservoirs could be referred to as bones and bloods, which might control the distribution of marine gas hydrates in the promising prospecting areas. In combination of anomalies related to hydrates, migrations of gas/fluids and favorable deep-water sediments, the predictions would be more accurate, which could be suggested as the developing trend of site selections for marine gas hydrates.