中文摘要：

海底天然气水合物采集样品的饱和度确定通常是通过密闭保压采样技术来实现，但采样器的温度压力控制非常困难．本文用热力学模型来模拟密闭体系下温度压力变化过程中甲烷在各相态中饱和度的变化过程，并在海洋水合物热力学系统基础上，完成了一项分析水合物原位饱和度的技术，其只要求采集器密闭，不需要进行严格的温度和压力控制，降低了对采样器的要求．实例分析显示，完全可以利用密闭样品在地表下气体和液体成分的测量，包括盐度的测量来估计出甲烷水合物原位饱和度．

英文摘要：

People generally use pressure core technology to collect marine gas hydrate samples to determine the saturation. But it＇s very difficult to control the temperature and pressure of the sampler. In this paper, we used a thermodynamic model to simulate the process of change in methane＇s saturation of each phase state in a closed system under the temperature and pressure changes. And we completed a technical analysis hydrate in situ saturation on the marine hydrate thermodynamic system. It only requires the sampler closed without the need for stringent temperature and pressure control. So, it reduces the requirements for the sampler. Examples of analysis showed that, we can estimate the in situ saturation of methane hydrate by measuring the enclosed sample＇s gas and liquid composition including salinity under the surface.