利用地球化学异常探测水合物

Prospecting Gas Hydrates by Geochemical Anomaly Methods

地球化学异常已成为天然气水合物研究的重要手段之一,是地球物理方法研究的补充。最近的研究发现地球化学是识别海底天然气水合物赋存的一种很有效方法。由大洋钻探ODP钻孔取上来的柱状岩心和孔隙水的地球化学异常,已建立了一套较为完整、可靠的识别水合物方法,同时还通过海底浅层(<20m)沉积物和孔隙水以及底层海水的地球化学分析来识别海底可能存在的天然气水合物,研究海底＼浅层沉积物和孔隙流水中的氧、锂、硫、盐碱度、甲烷浓度异常、氯离子浓度等地球化学异常标志,帮助寻找水合物及碳氢流体活动异常,圈定水合物可能存在的异常区。

Geochemical anomaly has become one of the most important methods for prospecting gas hydrates and also been complement of the geophysical survey. Resent researches have revealed that geochemical method is a more efficient way to indicate the gas hydrate occurrence in marine sediments. According to the geochemical anomaly analysis of core and pore water samples collected from ODP drills. A series of perfect and reliable methods for identifying hydrates have built. We can simultaneously identify possible survival gas hydrates through the geochemical analysis of shallow sediments(<20m) and pore waters and research oxygen, lithium and sulfide et al. in them. Besides we need to research the characteristics of geochemical anomalies such as saltness, methane concentration anomaly, chlorinity and so on.