The vessel was offset 30 m to the south, and Hole 1087B was spudded with the APC at 2317 hr. The recovery of the first core established the seafloor depth at 1383.5 mbrf. APC coring advanced without incident to 72.5 mbsf with 103.4% recovery. Cores were oriented starting with 3H. The bit was pulled out of the hole and cleared the seafloor at 0340 hr on 4 October, thereby ending Hole 1087B.
Hole 1087C was spudded with the APC at 0425 hr. The recovery of the first core established the seafloor depth at 1385.9 mbrf. Piston coring advanced to refusal at 248.6 mbsf. Cores were oriented starting with 4H. The hole was extended with the XCB to 491.9 mbsf with 91.8% recovery.
Logging Operations in Hole 1087C
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 442.8 mbsf, where the top drive was set back. The drill string was then placed at the logging depth of 85.8 mbsf. Logging operations began at 1930 hr on 5 October. The initial 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. This tool string was deployed in the pipe at 2015 hr and logged the hole down to and than up from 487.1 mbsf.
While attempting to recover the logging tool, the instrument hung up approximately 5 m inside the bit. Maximum overpull on the logging line was 1200 lbs. The logging tool was eventually freed from the bit by pumping. The logging winch operator tried to work the tool into the drill string again by incrementally pulling on the logging line up to a maximum of 4000 lbs head tension. This time the tool string became totally stuck in the bit and was unable to be worked up or down. Attempts at retrieving the logging tool with the logging cable were given up, and the Kinley cutter and crimper tools were prepared. The Kinley crimper was dropped, followed by a Kinley hammer. The drill string was pulled out of the hole, with the bit clearing the plane of the rotary table at 0715 hr. The logging tool was not recovered.
The vessel was offset 30 m to the south, and Hole 1087D was spudded at 1030 hr on 6 October. After drilling to 72.5 mbsf, piston coring was initiated. APC coring proceeded to 177.0 mbsf, which required the use of the last full-sized liner. A sole XCB core was then taken from 177.0 to 186.6 mbsf and recovered 9.88 m (102.9%). This core used the last liner on the vessel. The hole was then completed to a depth of 201.3 mbsf with two piston cores that were obtained without liners and recovered 100%. The total piston cored interval was 119.2 mbsf with 121.04 m (101.5%) recovered. The last core gave a total recovery for the leg of 8003.23 m. The drill string was then pulled out of the hole, with the bit clearing the seafloor at 2140 hr. The beacon was recovered at 2215 hr. The bit was at the rotary table at 0145 hr on 7 October. At 0700 hr on 7 October, the vessel departed the last site of Leg 175.
To 175 Operations Resume
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