IODP Expedition 385T
Panama Basin Crustal Architecture and Deep Biosphere: Revisiting Holes 504B and 896A
Daily Science Report for 15 September 2019
Location: B-Street Pier and Cruise Ship Terminal, San Diego, USA
Science Update: We completed the last 139 nmi of the 2779 nmi voyage from Site 504 to San Diego. The transit was completed at an average speed of 11.4 kt. Pilots boarded the vessel at 1400 h for the last 8 nmi of pilotage into the harbor, and the first line ashore ended Expedition 385T at 1500 h. U.S. Customs and Border Protection agents boarded the ship and cleared all departing personnel by 1800 h. IODP senior personnel came aboard and received debriefs from offgoing personnel. Port activities completed so far include offloading of 138 joints of 5½ inch drill pipe as well as one of the two polar containers.
Daily Science Report for 14 September 2019
Location: Underway to San Diego, USA
Science Update: Today we completed 227 nmi, and a total of 2648 nmi, of the 2779 nmi voyage from Site 504 to San Diego. Arrival at the pilot station is scheduled for 1400 h on 15 September (tomorrow), and the ship’s speed has been adjusted accordingly.
Daily Science Report for 13 September 2019
Location: Underway to San Diego, USA
Science Update: Today we completed 254 nmi, and a total of 2421 nmi, of the 2779 nmi voyage from Site 504 to San Diego. Arrival at the pilot station is scheduled for 1400 h on 15 September, and the ship’s speed has been adjusted accordingly.
Daily Science Report for 12 September 2019
Location: Underway to San Diego, USA
Science Update: Today we completed 261 nmi, and a total of 2169 nmi, of the 2779 nmi voyage from Site 504 to San Diego. Arrival at the pilot station is now scheduled for 1400 h on 15 September, and the ship’s speed has been adjusted accordingly.
Daily Science Report for 11 September 2019
Location: Underway to San Diego, USA
Science Update: Today we completed 282 nmi, and a total of 1908 nmi, of the 2779 nmi voyage from Site 504 to San Diego. Estimated time of arrival is 0600 h on 15 September 2019.
Daily Science Report for 10 September 2019
Location: Underway to San Diego, USA
Science Update: Today we completed 299 nmi, and a total of 1626 nmi, of the 2779 nmi voyage from Site 504 to San Diego. Estimated time of arrival is now 0600 h on 15 September 2019.
Daily Science Report for 9 September 2019
Location: Underway to San Diego, USA
Science Update: Today we completed 318 nmi, and a total of 1327 nmi, of the 2779 nmi voyage from Site 504 to San Diego. Estimated time of arrival is now 0800 h on 15 September 2019. The clocks were set back by 1 h at 0200 h.
The scientists completed the site and expedition reports.
Daily Science Report for 8 September 2019
Location: Underway to San Diego, USA
Science Update: Today we completed 306 nmi, and a total of 1009 nmi, of the 2779 nmi voyage from Site 504 to San Diego. Estimated time of arrival is now 1200 h on 15 September 2019.
Daily Science Report for 7 September 2019
Location: Underway to San Diego, USA
Science Update: Today we completed 286 nmi, and a total of 703 nmi, of the 2779 nmi voyage from Site 504 to San Diego. Estimated time of arrival is 1600 h on 15 September 2019.
Daily Science Report for 6 September 2019
Location: Underway to San Diego, USA
Science Update: Today we completed 284 nmi, and a total of 417 nmi, of the 2779 nmi voyage from Site 504 to San Diego.
Daily Science Report for 5 September 2019
Location:
Hole 504B (1°13.611′N, 83°43.818′W, water depth 3463 m)
Underway to San Diego, USA
Science Update: The rig floor crew continued to break down the drill pipe stands for storing and offloading in port. At 1200 h the lower guide horn was installed and the rig floor was secured for transit, which began at 1315 h. By midnight, we had completed the first 133 nmi of the 2779 nmi voyage from Site 504 to San Diego.
Daily Science Report for 4 September 2019
Location: Hole 504B (1°13.611′N, 83°43.818′W, water depth 3463 m)
Science Update: We continued to lower the drill string and deployed the subsea camera at 0200 h with the bit at 2730 m below rig floor (mbrf). As the camera was lowered, a shorted circuit in the camera system’s slip ring prevented it from being powered and the camera was retrieved (0305–0325 h). The milling bit was deployed to 3425 mbrf and the top drive was installed in anticipation of a successful and timely camera system repair. At 1245 h we determined that the camera could not be repaired in time to allow for reentry into Hole 504B and milling operations. The camera was lowered to depth and retrieved once more to coat the cable for long-term storage (1315–1615 h) before optical fibre splicing work continued on the slip ring. The top drive was set back and the drill pipe was retrieved with the bit clearing the rig floor at 2245 h. The rig crew began breaking down the drill pipe stands for storing and offloading in port.
Daily Science Report for 3 September 2019
Location: Hole 504B (1°13.611′N, 83°43.818′W, water depth 3463 m)
Science Update: We continued milling the packer in Hole 504B with the fourth milling bit, and by 1200 h we had advanced from 133 to 141 m below seafloor (mbsf). With ~13 h on the bit, we pulled out of the hole, set back the top drive, and cleared the seafloor at 1225 h. The milling bit cleared the rig floor at 1910 h. The bit face showed significant wear with three concentric patterns thought to be caused by the packer’s lower end cap, remains of its casing, and metal debris outside the bit.
At this point, obtaining downhole measurements or fluid samples became impossible in the remaining time, so the goal is to keep trying to open Hole 504B for potential future use. We made up the fifth milling bit with the bottom-hole assembly, this time again with the junk baskets. At 2015 h we began to lower the drill string to the seafloor, reaching 1432 m below rig floor (mbrf) by midnight.
Daily Science Report for 2 September 2019
Location: Hole 504B (1°13.611′N, 83°43.818′W, water depth 3463 m)
Science Update: We continued milling the packer in Hole 504B with the third milling bit, and by 0200 h it had advanced from 114 to 133 m below seafloor (mbsf). With ~9 h on the bit, we pulled out of the hole, set back the top drive, and cleared the seafloor at 0300 h. The bit cleared the rig floor at 0900 h. The junk baskets were disassembled, emptied, and cleaned, again yielding ~35 lb of metal debris mostly made up of steel slats.
We made up the fourth milling bit with the bottom-hole assembly, this time with additional drill collars for additional weight instead of the junk baskets. The drilling line was cut and slipped and additional rig maintenance was completed before the drill string was deployed to the seafloor. At 1850 h, with the bit at 2756 m below rig floor (mbrf), the subsea camera was deployed and Hole 504B was reentered for the fifth time at 2042 h. At 2245 h, after installing the top drive and retrieving the camera, milling in Hole 504B resumed from 133 m below seafloor (mbsf).
Daily Science Report for 1 September 2019
Location: Hole 504B (1°13.611′N, 83°43.818′W, water depth 3463 m)
Science Update: Following completion of the second milling attempt in Hole 504B yesterday, we began retrieving the drill string. The bit cleared the seafloor at 0018 h and arrived on deck at 0615 h. The junk baskets were disassembled, emptied, and cleaned, yielding ~35 lb of metal debris, mostly made up of steel baffling slats that were part of the central packer.
We made up the third milling bit with the bottom-hole assembly and began lowering it to the seafloor at 0815 h. At 1330 h, with the bit at 2586 m below rig floor (mbrf), the subsea camera was deployed and Hole 504B was reentered for the fourth time at 1537 h. At 1715 h, after installing the top drive and retrieving the camera, milling in Hole 504B resumed from 110 m below seafloor (mbsf). At midnight the bit was at 115 mbsf.