HR: 1330h
AN: T52C-0301    [PDF]
TI: On Physical Properties Acquired in ODP Logging and Possible Future Extensions in Log Interpretation -Leg 196 Nankai Seismogenic Zone Drilling-
AU: * Mikada, H
EM: mikada@jamstec.go.jp
AF: Deep Sea Research, JAMSTEC, 2-15 Natsushima-cho Yokosuka-shi, Kanagawa, 237-0061 Japan
AU: Henry, P
EM: henry@geologie.ens.fr
AF: College de France - Chaire de Geodynamique, Europole de l'Arbois Batiment Laennec, hall D, etage 2 BP 80, Aix en Provence, 13545 France
AU: Ienaga, M
EM: ienaga@ori.u-tokyo.ac.jp
AF: ORI, Univ. Tokyo, 1-15-1 Minamidai Nakano, Tokyo, 164-8639 Japan
AB: Leg-196 was conducted in May through June 2001 and continuous logging was performed using LWD. After the leg, post cruise studies are on-going and various results are now being published by the on-board researchers. The subjects of these studies include fluid flow, formation of decollement, stress fields, overpressures, etc. Although there are number of issues to be investigated using logging tools available commercially, there exist the limitations in the current ODP in the utilization of tools, such as nuclear magnetoresonance tools, ultrasonic tools, core samplers, dynamic testers, microscanners with doubled number of electrodes, multi-level borehole seismic sensors, etc. In the course of the hardware development in the science community, we expect to use these logging tools and to think what will be achieved in science with increased acquirable number of physical properties. We now focus the issue in terms of the following concepts: logged physical properties as an interface between core and seismic data, and how seismolithological methods to be applied to seismogenic studies. Additional properties which may be obtained in the future include multi-lateral resistivity profile for plural depths of investigations, both free and bound porosities, effective permeability, borehole electrical images in 5 mm resolution with doubled coverage, seismic anisotropy, etc. Cluster analyses would also become possible and be stably applied to data. We believe these physical properties would surely extend what we do with data to certain possible directions: fracture analyses, underground fluid circulations, stress orientations and possibly quantitative stress analyses, etc. We would like to discuss what could have been obtained if there were other physical properties available using examples from the leg-196.
DE: 0669 Scattering and diffraction
DE: 0915 Downhole methods
DE: 8105 Continental margins and sedimentary basins
SC: Tectonophysics [T]
MN: 2003 Fall Meeting