Por favor, use este identificador para citar o enlazar a este item:
http://hdl.handle.net/10261/182135
COMPARTIR / EXPORTAR:
SHARE BASE | |
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE | |
Título: | Wellbore failures and its constraints on the in-situ stress state in the Nankai Trough accretionary prism, Site C0002, IODP Expedition 348 |
Autor: | Sone, H.; Jurado, Maria José CSIC ORCID ; Boston, B.; Yamamoto, Y.; Tobin, H. J.; Saffer, D. M.; Hirose, T. | Palabras clave: | Fracture and flow Physical Property of rocks Seismology Tectonophysics Subduction zone processes Rheology and friction of fault zones Earthquake dynamics |
Fecha de publicación: | 15-dic-2014 | Editor: | American Geophysical Union | Citación: | American Geophysical Union, Fall Meeting 2014: T51A-4577 (2014) | Resumen: | The International Ocean Discovery Program (IODP) Expedition 348 extended the borehole of Site C0002, Nankai Trough, down to over 3000 meters below sea floor (mbsf) collecting core samples and in-situ geophysical data from the inner accretionary prism. In order to investigate the in-situ stress state within the prism, we characterized the occurrence and shapes of wellbore failures as observed by resistivity image logs and sonic caliper logs collected in the vertical well of Hole C0002P. Most wellbore failures were observed in the top 70 meters of Hole C0002P (2150 to 2218.5 mbsf), where resistivity images were acquired several days after the borehole was initially exposed by previous drilling and coring runs. Wide breakouts spanning up to 140 degrees are observed in the NW/SE to NNW/SSE direction suggesting that the maximum horizontal principal stress in the cored interval is in the direction generally consistent with those observed in the shallower sections of Site C0002 from earlier expeditions. In the remaining section of the borehole below, wellbore failures are much sparse and subtle in the resistivity image possibly due to the short exposure time between drilling and image acquisition (about 2 hours). Preliminary examination suggest that these features are breakouts aligned in the direction consistent with the upper section, but examination in combination with the sonic caliper data is required for further confirmation. These observations suggest that the occurrence of breakouts exhibit significant time-dependence due to processes such as pore pressure diffusion or time-dependent rock deformation. Moreover, sonic caliper data suggests that shapes and width of the wellbore failures in the studied dataset is influenced by the formation strength anisotropy (in the horizontal direction) enhanced by the steeply dipping bedding planes (60-90 degrees). Thus, constraints on in-situ stress magnitudes will be provided through comparison of wellbore failures, borehole cross section, bedding dips, downhole mud pressure records, and formation mechanical properties | URI: | http://hdl.handle.net/10261/182135 |
Aparece en las colecciones: | (Geo3Bcn) Comunicaciones congresos |
Ficheros en este ítem:
Fichero | Descripción | Tamaño | Formato | |
---|---|---|---|---|
accesoRestringido.pdf | 15,38 kB | Adobe PDF | Visualizar/Abrir |
CORE Recommender
Page view(s)
135
checked on 23-abr-2024
Download(s)
21
checked on 23-abr-2024
Google ScholarTM
Check
NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.