神狐海域与西沙海槽天然气水合物成藏模式对比

南海北部神狐海域与西沙海槽天然气水合物资源量丰富，但两地区天然气水合物成藏条件及成藏机制存在一定的差异。通过两海域水深、温度压力、气源、气体运移、储层等水合物成藏要素与成藏模式的分析对比，获取了3点新认识：①两地区海域水深、温压条件、气源类型、气体运移条件、水合物储层类型和成藏模式基本类似；②综合天然气水合物气源及供给运聚系统类型剖析，提出神狐海域主要以“自源与他源渗漏复合型”水合物成藏模式为主；③西沙海槽水合物成藏模式属典型的“他源渗漏型”。研究结果表明，落实气源与不同类型气体运移通道的时空耦合匹配关系是该区水合物勘探评价的关键。

A COMPARATIVE STUDY ON GAS HYDRATE ACCUMULATIONS IN SHENHU AREA AND XISHA TROUGH

There are great amount of natural gas hydrate resources in the Shenhu area and Xisha Trough, the north of South China Sea.However, there are differences in both the reservoir forming conditions and accumulation mechanism of gas hydrate between the two regions.In this paper, through the analysis and comparison of water depth, temperature, pressure, gas source, gas migration, as well as reservoir characters and other factors, we reached some conclusions as follows.①The two regions are similar in terms of water depth, temperature and pressure conditions, gas source type, gas migration conditions, hydrate reservoir type and reservoir characteristics.②Based on the analysis of the gas source, the supply and transportation system of natural gas, it is believed that the formation of gas hydrate in the Shenhu area is dominated by the "self-source and heterogeneous source leakage complex " model.③The gas hydrate in the Xisha Trough is a typical hydrate of "heterogeneous leakage type".The results of the study suggest that the time-space matching between gas source and migration channels is the key to the evaluation of hydrate exploration in this area.