Pipes are connected on the drill floor and run into the seabed. Hole C0006A was spudded into the seafloor at a depth of 3875 m water depth at 00:15 on 10 November. >>Expedition 314 Photo Gallery

IODP NanTroSEIZE Stage 1:
Expedition 314: NanTroSEIZE LWD Transect
Weekly Report #7
Date 09/Nov/2007

After the Pilot hole assembly from Hole C0004A was back on the drill floor, preparations began for the LWD assembly at 03:45, and a shallow hole test was made at 08:00 on 2 November. While running into the hole, Chikyu moved 2 nm up current to launch the ROV and then continued running into and tag seabed at 18:00 (2637 m water depth). We spudded Hole C0004B at 18:45, jetting down to 60.5 m at first, and then began rotary drilling at 20:15. After reaching the depth of 234.5 meters below the seafloor (mbsf), a short wiper trip was carried out between 234.5 and 99.5 mbsf from 03:30 for an hour on 3 November. Drilling continued and reached the Target Depth at 400 mbsf at 12:30. LWD tools were back on drill floor at 21:45 and data was retrieved at 00:00 of 4 November.
Recovering beacons from the seabed, moved to the next site. Chikyu moved 5 nm upstream at 16:12 and began drifting at 18:45 while running into the hole with a pilot hole assembly. The position of C0005A (NT2-01E) was confirmed at 00:45 of November 5, then we tagged the seabed and spudded the pilot hole at 01:00. The first 50 m was jetted in, and then rotary drilling began at 02:15. Soon after the short wiper trip was started from 524 mbsf at 17:00, overpull was observed at 486 mbsf. We tried to free and worked through the apparent pack off slowly. The pipe was reamed between 448 and 486 mbsf, and pulled out to 337 mbsf and then run back in to 450 mbsf. An attempt was made to ream to bottom and circulate at 19:30. However, the pipe became stuck at 461 mbsf at 20:15 and was freed after applying torque and work on the pipe. Unable to run in again to the previous depth, and with hole conditions worsening, a decision was made to pull out and abandon the hole at 23:00. The hole was displaced with kill mud at 385 m at 23:30, and we began pulling out at 00:00 of 6 November.

The ship moved to the NT2-01G location 300 m to the southeast, inside the same beacon network. The trouble of hydraulic power system of ROV was found and was recovered on deck for repair. Due to bad weather and strong current of 4.5 knots, the ROV was re-launched repeatedly during the day. Chikyu drifted 3.8 nm downstream and had to move back up current slowly with the drill string hung below the vessel. Started running into the hole again from 00:00 of 7 November. After the ship moved 2 km up current at 11:15, the pilot hole assembly began running in to the hole and tagged seabed at 2524.5 m water depth at 18:00. However, a problem of hydraulic pressure of the ROV was occurred, we finally decided at 19:00 to pull out from the depth of 37 mbsf, and move to NT1-03.

Chikyu moved to the location of NT1-03, and set beacons with the ROV at 04:15 on 8 November. Deploying 5 beacons and finished at 23:00, followed by the calibration of their position. Chikyu then moved 5 nm up current and the MWD pilot hole assembly was run in while checking pipe connections of every joint. Hole C0006A was spudded into the seafloor at a depth of 3875 m water depth at 00:15 on 10 November.

Review of the Site C0003 reports began 3 November. The science party began working on processing and interpretation of LWD-MWD data from the Site C0004 (NT2-01I) starting 4 November. The science party met on 5 November to review the processed sonic data results with the data and consulting services specialist. The expedition publications schedule was also confirmed in the meeting. On 7 November, a science meeting was held to discuss the change of drilling plan was made after delays from ROV troubles. Site summary meeting for the Site C0004 was made on 8 November and science party submitted their site report on 9 November for review.

Weekly safety drill (fire and abandon ship) was held on 4 November. At Lab, continued preparation for the following coring expeditions: maintenance and instrument setup of core splitter, pycnometer, MSCL-C, ion chromatograph and titrator, SQUID, carbonate analyzer; training of Xray CT, MSCL-W, core splitter and SQUID operations and core location management system. Also carried out carrying core racks from lab to containers.