Abstract Gas hydrate quantification using acoustic data requires proper knowledge of the mineralogy of their host sediment. In this paper, a petrophysical model allowing GH quantification at sites where mineralogy profiles are absent is proposed. This approach is applied to a high gas flux pockmark system in the Gulf of Guinea where in-situ acoustic and geotechnical measurements together with core measurements could have been correlated and tied to seismic data. Projections of the in-situ measurements on seismic profiles have shown that the study area not only accommodates zones of shallow and dense GH; but also zones where solid hydrate and free gas coexist as well as pockets of free gas. Further analysis of several seismic profiles has allowed illustrating the detailed GH occurrence zone within the study area, estimate its volume and its occupancy ratio of the pockmark. Correlations between GH content and 3D bathymetry sections have allowed to draw a link between different GH contents and the morphology of the pockmark, which also shares similarities with the morphology of the GH occurrence zone it accommodates.

中文翻译：

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尼日利亚边缘的海底洼地：海底形态和海底水合物分布

摘要 使用声学数据对天然气水合物进行量化需要对其寄主沉积物的矿物学有适当的了解。在本文中，提出了一种允许在没有矿物学剖面的地点进行 GH 量化的岩石物理模型。这种方法应用于几内亚湾的高气体通量麻点系统，在该系统中，原位声学和岩土工程测量以及岩心测量可以与地震数据相关联。地震剖面原位测量的预测表明，研究区不仅容纳了浅而致密的GH带；还有固体水合物和游离气体共存的区域以及游离气体的口袋。对几个地震剖面的进一步分析可以说明研究区域内详细的 GH 发生带，估计它的体积和麻点的占有率。GH 含量和 3D 测深剖面之间的相关性允许在不同的 GH 含量和麻点形态之间建立联系，这也与它所容纳的 GH 发生区的形态有相似之处。