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| Gay, Aurelien; Lopez, M; Cochonat, Pierre; Seranne, M; Levache, D; Sermondadaz, G. |
| Based on high-resolution 3D seismic data sets, we document the subsurface reservoir architecture and organization of a portion of the Oligocene-Miocene stratigraphy within the Congo Basin, offshore southwestern Africa. Within the 3D seismic volume, we have identified four levels of turbiditic palaeochannels, which are separated by low-amplitude continuous reflectors interpreted as hemipelagic sediments. Geochemical analyses on sediment samples taken within overlying seafloor pockmarks reveal the presence of thermogenic gases and oils, suggesting that deep-seated fluids have migrated through both the channel deposits and the impermeable layers between them, forming a conduit to the surface. Deep thermogenic fluids produced within Cretaceous source rocks are... |
| Tipo: Text |
Palavras-chave: Polygonal faults; BSR; Fluid chimneys; Pipes; Hydrates; Turbiditic palaeochannels; Pockmarks; Fluid migration. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1111.pdf |
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| Gay, A; Lopez, M; Cochonat, Pierre; Levache, D; Sermondadaz, G; Seranne, M. |
| Using high quality 3D seismic data within the Lower Congo Basin (LCB), we have identified pockmarks that are aligned above the sinuous belt of a buried turbiditic palaeo-channel, 1000 m beneath the seafloor. Geochemical analyses on cores (GC traces), taken in the centre of four of these pockmarks along this channel, show no clear evidence for migrated oil. But, some features of the GC traces, including elevated baselines (UCM > 34 mu g/g) and a broad molecular weight range of n-alkanes with little odd-even preference, may be interpreted as indicating the presence of thermogenic hydrocarbons in the cores. Seismic profiles show that these pockmarks developed above two-main features representative of pore fluid escape during early compaction: (1) closely... |
| Tipo: Text |
Palavras-chave: Pipes; Seismic chimneys; Polygonal faults; Fluid migration; Turbiditic channels; Pockmarks. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1673.pdf |
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