The sizeable southern swell caused the voyage across the Tasman Sea to be slower than expected (9.6 kt average speed) and less comfortable than hoped for. When the vessel cleared the Foveaux Strait between the South Island and Stewart Island and turned northeast, the seas calmed and the vessel speed increased to 12 kt. Because no seismic survey was required, the vessel proceeded directly to the Global Positioning System (GPS) coordinates of the location.
The positioning beacon was dropped at 0342 hr on 23 August 1998. The APC/XCB bottom-hole assembly (BHA) was assembled using an 11-7/16-in used RBI C-3 bit with a lockable float valve (LFV) and deployed. Hole 1119A was spudded with the APC at 1015 hr on 23 August. The recovery indicated that the water depth referenced to the dual elevator stool (DES) was 406.5 meters below rig floor (mbrf), equivalent to 395.50 meters below sea level (mbsl). Hole 1119A is a single core hole designated for mudline sampling.
The second hole of the site was spudded with the APC at 1050 hr on 23 August without offsetting the vessel. The seafloor depth inferred from recovery was 407.8 mbrf (396.8 mbsl). APC coring proceeded to 155.8 meters below seafloor (mbsf) when Core 181-1119B-17H did not achieve full stroke. Cores were oriented starting with 181-1119B-3H. Heat-flow measurements were attempted with the Adara heat-flow shoe at 33.2 mbsf (4H), 61.7 mbsf (7H), 90.2 mbsf (10H), and 118.7 mbsf (13H), but could not be retrieved because the instrument had an electronic failure. The drill bit cleared the seafloor at 0020 hr on 24 August.
The vessel was offset 20 m to the east and the bit was lowered 3 m before the initial mud line attempt to provide stratigraphic overlap in the sedimentary record. The seafloor depth inferred from recovery was 407.2 mbrf (396.2 mbsl). APC coring advanced to 160.3 mbsf where piston coring was concluded when Core 181-1119C-17H failed to achieve a full stroke. XCB coring deepened the hole to the depth objective of 494.8 mbsf. No hole problems were encountered.
Logging Operations at Hole 1119C
After pumping down the aluminum "go-devil," the hole was flushed with 60 barrels of high viscosity mud. The drill string was pulled back in the hole to logging depth where the bit was positioned at 95.0 mbsf. Three logging measurements were scheduled for this hole. Logging operations began at ~2300 hr on 25 August. Three standard tool-string configurations were run: the triple combination, the Formation MicroScanner (FMS) with a sonic sensor (two passes), and the Geologic High Resolution Magnetic Tool (GHMT). Logging was conducted below the pipe at 80 mbsf to a hole obstruction at ~40 m above the bottom of the hole. The hole quality was poor, with an uneven borehole wall and many breakouts and ledges. The NUMRS tool (total magnetic field) on the GHMT suite failed to collect data for unknown reasons.
After logging was concluded by 1330 hr on 26 August, the Schlumberger equipment was dismantled. The drill pipe was lowered to 454 mbsf and the circulating head made up to the pipe. After filling the hole with 170 barrels of 12 pounds per gallon (1438 kg/m3) heavy mud, the drill string was pulled out of the hole. While the drill string was being retrieved, the beacon was released and recovered, and the hydrophones and thrusters retracted and secured. At 1915 hr on 26 August, the vessel was under way to Site 1120.
To 181 Summary of Engineering and Drilling Operations: Site 1120
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