海域天然气水合物勘测的地球物理方法

Geophysical methods for marine gas hydrates exploration

到目前为止,已经探明的天然气水合物储量要远小于预测的水合物储量.这种现状不同程度地反映出我们对天然气水合物赋存规律认识不足,和对天然气水合物勘探方法认识不足.本文根据作者多次参加水合物地球物理调查国际航次的认识及文献资料,综述了海域天然气水合物勘探方面一些有效的地球物理技术方法,以利于我国海域天然气水合物的勘探工作以及勘探方法的创新.本文指出,地震勘探是目前进行天然气水合物勘探最常用、也是最重要的方法.地震方法主要包括传统的单道、多道地震方法、高分辨地震方法、深拖多道地震探测方法、海底地震仪方法、多道-多分量海底地震电缆方法、海底地震检波器方法等.此外,根据水合物发育区特有的海底地形地貌特征和水体异常特征,根据水合物发育所需要的温度-压力场特征、电磁特征和含水合物地层的剪切模量特征发展的多波束方法、旁扫声纳方法、海底热流探测方法、海底电磁方法以及海底重力测量方法等都在海域天然气水合物勘探中有着很好的效果.

Up to now, there are big different between the amount of gas hydrates explored and the amount of gas hydrates estimated. This situation clearly shows our short of understanding of formation mechanism of natural gas hydrates and also our short of understanding of gas hydrates exploration methods. Based on the experiences from international gas hydrates exploration cruises, and for short the different stated above, this paper review the geophysical methods used for gas hydrates exploration. The paper shows that seismic method including single channel, multi- channel, high frequency, deep tow multi-channel, OBS, OBC, OBH method, is the most popular and most important method used for gas hydrates exploration. Multi-beam, side scan sonar, heat flow probe, electronic and magnetic observer, and sea bottom gravity meter also successfully used in the gas hydrates exploration.