Logging Operations in Hole 1084A
In preparation for logging, an aluminum go-devil was dropped to ensure the opening of the lockable float valve. After the hole was flushed with a high-viscosity mud treatment, the drill string was pulled back to 565.5 mbsf, where the top drive was set back. The drill string was then placed at the logging depth of 89.7 mbsf.
Hole 1084A was logged with a full suite of sensors. For each run, the pipe was set at 89.7 mbsf and pulled back to 59.0 mbsf during logging. The wireline logging heave compensator was started when the logging tools reached the mudline. Logging operations began at 0715 hr on 23 September. The first log was conducted with the seismic-stratigraphic suite (25.8 m long). This suite was made up of the NGT, LSS, DITE-SFR, and TLT sondes. The tool string was deployed in the pipe at 0905 hr and logged the hole up from 601.0 mbsf. The tool was recovered at 1330 hr. The second log was run with the lithoporosity suite (19.5 m long) and included the hostile HNGS, APS, LDS, and TLT sondes. The tool was deployed at 1425 hr and logged the hole from 601.0 mbsf. The tool was retrieved at 1900 hr. The third log was made with the FMS suite (12.10 m long) and included the NGT, GPIT, and FMS sondes. This tool was deployed at 2310 hr and logged the hole from 604.5 mbsf. The tool was recovered by 2245 hr. The fourth and last log was with the magnetic susceptibility suite (11.8 m long) and included the NGT, SUMT, and NRMT sondes. The tool was deployed in the pipe at 2310 hr and logged the hole from 603.6 mbsf. It was retrieved at 0210 hr on 24 September. The logging equipment was rigged down by 0300 hr. The drill string was then pulled out of the hole, with the bit clearing the seafloor at 0315 hr on 24 September.
The vessel was offset 30 m to the north and Hole 1084B was spudded with the APC at 0415 hr. The recovery of the first core established the seafloor depth at 2004.4 m. APC coring advanced without incident to refusal at 182.8 mbsf (Cores 175-1084B-1H through 20H) with 102.1% recovery. Cores were oriented starting with 4H. The bit cleared the seafloor at 1750 hr on 24 September, thereby ending operations at Hole 1084B.
The vessel was offset 30 m to the north, and Hole 1084C was spudded with the APC on 24 September. The recovery of the first core established the seafloor depth at 2002.0 m. APC coring advanced to 202.0 mbsf (Cores 175-1084C-1H through 22H) with 104.9% recovery. Cores were oriented starting with 3H. The drill string was retrieved, with the bit clearing the seafloor at 0835 hr and the plane of the rotary table at 1225 hr on 25 September, thereby ending operations at Site 1084.
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