|
|
|
|
|
| Sultan, Nabil; Riboulot, Vincent; Ker, Stephan; Marsset, Bruno; Geli, Louis; Tary, Jean-baptiste; Klingelhoefer, Frauke; Voisset, Michel; Lanfumey, Valentine; Colliat, Jean-louis; Adamy, Jerome; Grimaud, S.. |
| Gas hydrates were recovered by coring at the eastern border of a shale-cored anticline in the eastern Niger Delta. To characterize the link between faults and fluid release and to identify the role of fluid flow in the gas hydrate dynamics, three piezometers were deployed for periods ranging from 387 to 435 days. Two of them were deployed along a major fault linked to a shallow hydrocarbon reservoir while the third monitored the fluid pressure in a pockmark aligned above the same major fault. In addition, 10 ocean-bottom seismometers (OBS) were deployed for around 60 days. The piezometers simultaneously registered a prolonged fluid flow event lasting 90 days. During this time, OBS measurements record several episodic fluid release events. By combining and... |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00060/17106/14624.pdf |
| |
|
|
| Wei, Jiangong; Pape, Thomas; Sultan, Nabil; Colliat, Jean-louis; Himmler, Tobias; Ruffine, Livio; De Prunele, Alexis; Dennielou, Bernard; Garziglia, Sebastien; Marsset, Tania; Peters, Carl A.; Rabiu, Abdulkarim; Bohrmann, Gerhard. |
| A joint research expedition between the French IFREMER and the German MARUM was conducted in 2011 using the R/V Pourquoi pas? to study gas hydrate distributions in a pockmark field (1141 – 1199 meters below sea surface) at the continental margin of Nigeria. The sea floor drill rig MeBo of MARUM was used to recover sediments as deep as 56.74 meters below seafloor. The presence of gas hydrates in specific core sections was deduced from temperature anomalies recorded during continuous records of infrared thermal scanning and anomalies in pore water chloride concentrations. In situ sediment temperature measurements showed elevated geothermal gradients of up to 258 °C/km in the center of the so-called pockmark A which is up to 4.6 times higher than that in the... |
| Tipo: Text |
Palavras-chave: Gas hydrate; Pockmark; Chloride profile; Infrared thermal imaging; Fluid flow; Nigerian continental margin; MeBo drill rig. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00213/32382/30846.pdf |
| |
|
|
| Sultan, Nabil; Garziglia, Sebastien; Colliat, Jean-louis. |
| Published laboratory geotechnical data by Masui and co-authors showed that increase in gas hydrates content tend to increase the peak shear strength and stimulate strain softening of the host sediment. Therefore, development of shear strains may lead to an important degradation of the shear strength (strain softening). In the present work, the strain softening of gas hydrate-bearing sediments was implemented in a 3D slope stability model (SAMU-3D). This was done by adding to the classical limit analysis method a shear strain field compatibility equivalent to the velocity field compatibility. Examples of slope failures related to strain softening behavior documented in the literature were used to test the model formulation. The developed model was then used... |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14625/11903.pdf |
| |
|
|
|
