The 0.6 nmi transit was made in 1 hr in DP mode while running pipe. A Datasonics 354M beacon was deployed twice and released for unknown reasons; therefore, another beacon was dropped. Hole 857D had been drilled to 936 m on Leg 139 and has a reentry cone with 11-3/4" casing set at 573.8 m (3005.0 mbrf). The water depth is 2431.5 mbrf. A CORK was set with a 300-m-long thermistor and fluid sampler string. The CORK was knocked over on Leg 146 by a collision with the running tool in high heave conditions. The Alvin submersible installed an overshot on the data logger in a subsequent unsuccessful fishing attempt, but the rope broke. The object was to retrieve the damaged CORK and 300-m thermistor string, deepen the hole, and reCORK the hole.
A CORK pulling BHA was run consisting of: CORK running tool, seal bore pony DC, 5 joints 8-1/4" DC, tapered DC, 6 joints of 5-1/2" DP, crossover. The running tool was stabbed over the damaged CORK data logger at 1945 hr on 5 September. An unsuccessful attempt was made to wash down over the CORK. Interference with the ROV platform was suspected (the platform was damaged from a heavy blow on Leg 146); therefore, the platform pulling tool was dropped. The platform pulling tool engaged both arms, and the platform came free with 40 Kips pull. No other fish could be seen and the platform was dropped on the seafloor 70 m southwest of Hole 857D to save time.
On returning to the platform, it was noted that the data logger was missing and a fish was in the CORK pulling tool. The data logger was recovered with the upper CORK body (above the sealing bulkhead and six release rods). The 300-m thermistor string and sinker bar was lost in the hole. The CORK body had few deposits and appeared to have been an effective seal. A long length of rope dumped by the Alvin was wrapped around the CORK body while dropping the platform. The remaining CORK fish was a 5-1/4 in. diameter data logger seal sleeve and mandrel extending 26 in. above a sealing bulkhead, with a latch ring, seal, and lower CORK body below. The seal sleeve was 10 in. below the throat (if all of the fish was recovered after rotating in the sea floor to dump the platform). An 8-7/8 in. overshot with a 5-3/8 in. basket grapple was slightly larger than desirable; however, it was the closest catch size available for an outside catch of the fish. The cut lip guide was shortened, and a 22 in. funnel was welded above the overshot to act as a centering guide in the 24 in. wide reentry cone throat. A bumper sub was run because the weather was deteriorating rapidly with 18-27 kt winds and rain.
The overshot could not be stabbed over the fish, and marks on the overshot indicated that the centering guide was ineffective because it was too far above the cut lip guide. The centering guide could not be welded to the overshot body; therefore, it was welded on a short 9-5/8 in. stem so the funnel could be positioned just above the cut lip guide. The overshot assembly was run again without the bumper sub. The overshot was engaged and the fish pulled free with 30K lb. The ship was offset 70 m southwest, and the overshot was pulled. No fish was recovered; however, the grapple indicated it had been over a fish; therefore, it was assumed that the fish was dropped on the seafloor to the southwest. A wireline spear was selected to fish the thermistor string, sinker bar, and the bottom of the data logger (if they remained in the hole). The spear had a hole in the nose so the temperature and fluid samplers were checked to ensure adequate internal clearance and the top plate and nose holes were beveled. The wireline spear was run in to the seafloor, and the seafloor was searched for the dropped fish without success. The spear reentered Hole 857D, and tagged an obstruction at 20.8 mbsf. The spear was rotated to secure the cable fish, and pulled to the ship with cable trailing from the cone throat. The ship was turned broadside to the current, the center thrusters were shut down, and observers were posted to look for floating cable as a precaution. A significant portion of the thermistor string was recovered (but not the sinker bar), consisting of >200 m of braided kevlar cable and tygon water sample tube. The water sample tube was clamped off in sections to preserve fluid samples. The braided kevlar jacket had deteriorated progressively with depth below 200 m. The bottom of the sample tube was colored and plugged with clay, indicating possible contact with sediments. Four 1/2 by 3 in. long spear prongs were left in the hole in addition to the 270-lb thermistor sinker bar. The temperature and fluid sampler tools were being serviced and repaired; therefore, a decision was made to go to Site 1035, and the beacon (S/N 1253) was turned off. The bit cleared the rotary table at 2100 hr on 7 September.
To 169 Site 1035
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