TRANSIT TO SITE 1110 (ACE-10A)
Because we had left a positioning beacon at Site 1108, we traveled to that site during the transit to Site 1110 (ACE-10A). The drilling line was slipped and cut while under way. Once arriving at Site 1108, we signaled the beacon to release and lowered the thrusters. The beacon was successfully recovered at 0245 hr on 4 July 1998. While the ship moved the final 3.3 nmi (6.1 km) to Site 1110 in dynamic positioning mode, we put together the APC/XCB coring assembly and began to run in the hole to save rig time.
At 0600 hr on 4 July 1998 the positioning beacon for Site 1110 was deployed. The pipe was lowered the remaining distance to the seafloor and Hole 1110A was spudded at 0945 hr. Core 1H was taken with the bit at 3243.9 mbsl and recovered 7.03 m; therefore, the seafloor was calculated to be at 3246.4 mbsl. Core 2H failed to fully stroke and recovered 2.5 m of sand and gravel. We terminated this hole at a total depth of 9.5 mbsf, and Hole 1110A ended at 1100 hr when the pipe was pulled clear of the mudline.
Without offsetting the ship, we spudded Hole 1110B at 1130 hr on 4 July 1998. Core 1H was taken with the bit at 3241.9 mbsl and recovered 5.08 m; therefore, the seafloor was calculated to be at 3246.3 mbsl. We then switched to XCB coring. Core 3X took ~2.5 hr to cut and was recovered with the soft formation XCB cutting structure destroyed. High and erratic torque, slow ROP, and very low recovery was enough to convince us that the XCB system was not well suited to the formation. Coring was terminated at a total depth of 22.3 mbsf, the drill string recovered, and Hole 1110B ended at 2330 hrs on 4 July when the bit cleared the rig floor.
After assembling an RCB BHA, we tripped the pipe back to the seafloor. The ship was offset 30 m on a course of 280°, and we spudded Hole 1110C at 0545 hr on 5 July. A seafloor depth of 3246 mbsl was determined by tagging the seafloor with the drilling assembly. Repeated attempts were made to drill ahead with a center bit in place. After 7 hr of high torque, packing off, overpull, fill, and extremely slow penetration, it became painfully clear that a satisfactory hole was not going to be possible at this location. The hole was terminated after penetrating a mere 15.0 mbsf without even attempting to cut a single core. Hole 1110C ended at 1300 hr on 5 July when the bit cleared the mudline.
The center bit was recovered and a core barrel was deployed. The ship was offset 30 m north and 30 m east before we spudded Hole 1110D at 1430 hr on 5 July. The seafloor was tagged at 3245.8 mbsl, and drilling (without coring) proceeded to a depth of 22.7 mbsf. A single core was cut to a depth of 28.7 mbsf before we abandoned this hole for the same reason as Hole 1110C. High torque, packing off, overpull, and generally poor hole conditions prevailed once again. The drill pipe was pulled clear of the seafloor at 1845 hr officially ending Hole 1110C, and the core barrel was retrieved while we waited for the released positioning beacon to surface. Recovery for the 6.0-m interval cored was 0.16 m (2.7%).
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