IODP

doi:10.2204/iodp.sp.315.2007

Site summaries (continued)

Proposed Site NT2-01B
Priority:
Primary:
Chikyu Expedition 314 (LWD)
Chikyu Expedition 316 (Thrust Faults)
Position:
33°13.3200′N, 136°42.2000′E
Water depth (m):
2391
Target drilling depth (mbsf):
1000 m sediment
Approved maximum penetration (mbsf):
1200; approved by CDEX and TAMU safety panels based on EPSP Jan 2007 recommendation
Survey coverage:
CDEX 2006 3-D MCS; extensive survey data outlined in Proposal 603A-Full2 (www.iodp.org/nantroseize-downloads):
• Track map (Fig. AF23)
• 3-D Inline 2596 (Figs. AF24, AF25)
• 3-D Crossline 5375 (Fig. AF26)
Objective
(see text for full details):
Characterization of active splay fault and fluid flow regime by core sampling, logging, crosshole experiments and long-term monitoring
Focus on mechanical and hydrological properties (e.g., strength, pore pressure, permeability, porosity), fluid budget, origin of the fluid, detection of episodic flow
Borehole long-term observatory for hydrogeological properties and crosshole testing planned for future stages
Drilling, coring, and downhole measurement program:
Chikyu Expedition 314 (LWD):
Hole A - MWD/LWD to 1000 m
Chikyu Expedition 316 (Thrust Faults):
Hole B:
• Jet-in test
• APC/XCB coring and downhole measurements (temperature, core orientation)
Hole C:
• Install reentry cone and casing
• RCB coring to TD
• Case hole to TD
• Wireline logging only as contingency in case Chikyu Expedition 314 LWD is not successful
Anticipated lithology:
0–100 mbsf: slope sediments
100–610 mbsf: accretionary prism (deformed, compacted turbidites)
~610 mbsf: megasplay fault
610–910: younger slope sediments
>910 mbsf: older accretionary prism sediments and rocks