Volume of natural gas within gas-hydrate and free-gas occurrences in ODP Leg 164 sites

Leg 164 of the Ocean Drilling Program was designed to investigate the occurrence of gas hydrate in the sedimentary section beneath the Blake Ridge on the southeastern continental margin of North America. Sites 994, 995, and 997 were drilled on the Blake Ridge to refine our understanding of the in situ characteristics of natural gas hydrate. Because gas hydrate is unstable at surface pressure and temperature conditions, a major emphasis was placed on the downhole logging program to determine the in situ physical properties of the gas hydrate-bearing sediments. Downhole logging tool strings deployed on Leg 164 included the Schlumberger quad-combination tool (NGT, LSS/SDT, DIT, CNT-G, HLDT), the Formation MicroScanner (FMS), and the Geochemical Combination Tool (GST). […]

大洋钻探计划（Ocean Drilling Program）第164航次旨在探究北美东南大陆边缘布雷克海岭下方沉积剖面中天然气水合物（gas hydrate）的赋存状态。研究团队在布雷克海岭布设了994、995及997三个钻探站位，以深化对天然气水合物原位（in situ）物理特征的认知。鉴于天然气水合物在地表温压条件下不稳定，本次航次重点开展井下测井项目，以获取含天然气水合物沉积物的原位物理性质数据。本航次部署的井下测井仪串包括斯伦贝谢（Schlumberger）四组合测井仪（含NGT、LSS/SDT、DIT、CNT-G、HLDT）、地层微扫描仪（Formation MicroScanner，FMS）以及地球化学组合测井仪（Geochemical Combination Tool，GST）。[…]