IODP Expedition 384
Engineering Testing
Daily Science Report for 24 August 2020
Location: Berth 21, Port of Kristiansand, Norway
Science Update: We completed the last 61 nmi of the 1174 nmi transit to Kristiansand. The pilot was on board at 0704 h and the first line was ashore at 0839 h, ending Expedition 384 and beginning Expedition 390P.
The failed logging winch motor is scheduled for pickup at 0800 h on 25 August.
Expedition 384 JRSO staff will complete the expedition reports and preparation of Hole U1555G core samples for Expedition 395 scientists, and continue working on laboratory maintenance and development activities until 5 September.
Daily Science Report for 23 August 2020
Location: In transit to Kristiansand, Norway
Science Update: We completed 164 nmi, for a total of 1113 nmi of the 1174 nmi transit to Kristiansand. Arrival at the pilot station in Kristiansand is scheduled for 0700 h on 24 August.
JRSO personnel kept working on Hole U1555G core sample preparation for the Expedition 395 scientists as well as on Expedition 384 reports.
Daily Science Report for 22 August 2020
Location: In transit to Kristiansand, Norway
Science Update: We completed 184 nmi, for a total of 949 of the 1174 nmi transit to Kristiansand. Expected time of arrival at the pilot station in Kristiansand is 0700 h on 24 August.
JRSO staff are preparing the expedition reports.
Daily Science Report for 21 August 2020
Location: In transit to Kristiansand, Norway
Science Update: We completed 253 nmi, for a total of 765 of the 1174 nmi transit to Kristiansand. Expected time of arrival at the pilot station in Kristiansand is 0700 h on 24 August.
JRSO staff are preparing the expedition reports.
Daily Science Report for 20 August 2020
Location: In transit to Kristiansand, Norway
Science Update: We completed 113 nmi, for a total of 512 of the 1174 nmi transit to Kristiansand. By midnight we had left the choppy seas behind us and were back to full speed (11.4 kt).
The ship’s clock was advanced by 1 h, to UTC + 2 h, at 0200–0300 h. Expected time of arrival in Kristiansand is 0700 h on 24 August.
Daily Science Report for 19 August 2020
Location: In transit to Kristiansand, Norway
Science Update: We completed 221 nmi, for a total of 399 of the 1174 nmi transit to Kristiansand. By midnight the ship’s speed was reduced to 3.7 kt due to high seas.
The ship’s clock will be advanced by 1 h, to UTC + 2 h, at 0200 h on 20 August. Expected time of arrival in Kristiansand is 23 August.
Daily Science Report for 18 August 2020
Location: In transit to Kristiansand, Norway
Science Update: The logging winch electric drive motor was disassembled and found not to be repairable on board. The ship switched from dynamic positioning to cruise mode, and we left Site U1555 at 0812 h for the transit to Kristiansand, Norway.
Daily Science Report for 17 August 2020
Location: Site U1555 (60°13.686′N, 28°30.002′W; water depth 1523 m; proposed Site REYK-13A)
Science Update: Shipboard engineers spent the day disconnecting and disassembling parts of the broken-down wireline logging winch to assess its condition.
In the Core Laboratory, curation, measurement, and sampling of the cores from Hole U1555G continued.
Daily Science Report for 16 August 2020
Location: Site U1555 (60°13.686′N, 28°30.002′W; water depth 1523 m; proposed Site REYK-13A)
Science Update: With the end of the pipe at 85.7 m driller’s depth below sea floor (DSF) in Hole U1555G, the triple combo wireline logging tool string was rigged up in preparation for logging the sediment section. At 0500 h, while the tool string was being deployed down the drill pipe, the logging line winch motor failed. The logging line was transferred over to the coring line winch and the logging tools were recovered by 1330 h. At this point, drilling and coring operations had to be suspended for safety reasons because a functioning logging winch is required in case the drill pipe gets stuck and needs to be severed. The drill string was retrieved and cleared the rig floor at 2300 h, ending operations in Hole U1555G. The bottom-hole assembly was broken down so the collars could be laid down and the rig floor secured for potential transit and/or weather.
The technical staff continued to split, curate, and image the basalt cores from Hole U1555G.
Daily Science Report for 15 August 2020
Location: Hole U1555G (60°13.685′N, 28°30.000′W; water depth 1523 m; proposed Site REYK-13A)
Science Update: We began the day ready for wireline logging in Hole U1555G, with the end of the drill pipe at 202.4 m driller’s depth below seafloor (DSF), or ~24 m below the sediment/basalt interface. The triple combo tool string was deployed from 0300 to 1000 h. This tool string measures electrical resistivity, density, porosity, magnetic susceptibility, and natural gamma radiation in the formation. The first of two logging passes with the tool string reached a maximum depth of 305.5 m wireline log depth below seafloor (WSF), where tight hole conditions were encountered.
The second tool string included the Dipole Sonic Imager and Formation MicroScanner systems and was deployed from 1000 to 1545 h. This tool string reached a maximum depth of 295.4 m WSF and encountered tight hole conditions at 270.4 m WSF.
The third tool string included the Versatile Seismic Imager. It was deployed from 1545 to 2245 h while maintaining the appropriate marine mammal and protected species observation procedures, including an initial ramp up and a suspension and repeated ramp up when whales were observed. Successful recordings were achieved at two depth stations in the open basement hole.
The hole was displaced with heavy (10.5 lb/gal) mud, and the end of pipe was raised to 85.7 m DSF in preparation for logging the sediment section.
The technical staff continued to split, curate, and image the basalt cores from Hole U1555G.
Daily Science Report for 14 August 2020
Location: Hole U1555G (60°13.685′N, 28°30.000′W; water depth 1523 m; proposed Site REYK-13A)
Science Update: We continued coring the basalt basement in Hole U1555G and completed the final interval from 266.0 to 309.5 m driller’s depth below seafloor (DSF) at 2000 h. Cores U1555G-19R through 27R advanced 43.5 m and recovered 17.6 m (41%).
In summary, we drilled in Hole U1555G without coring from the seafloor to 168.6 m DSF, advanced the first core barrel 2R from 168.6 to 178.3 m DSF and recovered 0.66 m of sediment above a 5 cm long piece of basalt, and advanced in basement to 309.5 m DSF (131.2 m basalt penetration) with Cores 3R though 27R. We recovered a total of 59.6 m of basalt (45%) in 70 h of coring operations.
The hole was swept with 50 barrels of sepiolite mud. At 2230 h the coring bit was released to the bottom of the hole. In preparation for logging, the hole was displaced with heavy mud (barite-weighted to 10.5 lb/gal), and the end of the drill pipe was raised to 202.4 m DSF (~24 m below the sediment/basalt interface).
Daily Science Report for 13 August 2020
Location: Hole U1555G (60°13.685′N, 28°30.000′W; water depth 1523 m; proposed Site REYK-13A)
Science Update: We continued coring the basalt basement in Hole U1555G from 226.9 to 266.0 m driller’s depth below seafloor (DSF). Cores U1555G-11R through 18R advanced 39.1 m and recovered 18.7 m (48%). The objective is to core ~130 m of basement, or to ~305 m DSF, and then log the hole.
The IODP JRSO staff started processing the cores in consultation with Expedition 395 scientists.
Daily Science Report for 12 August 2020
Location: Hole U1555G (60°13.685′N, 28°30.000′W; water depth 1523 m; proposed Site REYK-13A)
Science Update: After drilling ahead in Hole U1555G through the sediment section to 168.6 m driller’s depth below sea floor (DSF), we cored the basalt basement to 226.9 m DSF. Cores U1555G-2R through 10R advanced 58.3 m and recovered 24.0 m (41%). The objective is to core ~130 m of basement, or to ~300 m DSF.
We established a protocol to engage the Expedition 395 science party on shore in selecting pilot samples. We are sending daily batches of whole-round core section images with proposed splitting lines to shore for review, as well as the location of a few whole-round samples for engineering analyses. Once we receive feedback, we split the cores and image the archive section-half cut faces. These images are also sent to shore so Expedition 395 petrologists can select the locations of thin section and geochemistry samples to be taken aboard. This 24–36 h communication turnaround will be maintained as long as shipboard laboratory work can be completed in the time available on Expedition 384.
Daily Science Report for 11 August 2020
Location: Hole U1555G (60°13.685′N, 28°30.000′W; water depth 1523 m; proposed Site REYK-13A)
Science Update: We terminated RCB coring with the PDC bit at 0600 h, after retrieving Core U1555F-9R from a total depth of 184.3 m driller’s depth below sea floor (DSF). Although the cores we recovered in Hole U1555F were better trimmed than the typical RCB cores cut with our regular bits, the rate of penetration became unacceptably low. Cores U1555F-3R through 9R advanced a total of 8.1 m over a period of ~26 h with a recovery of 5.81 m (72%). We retrieved the drill string with the bit clearing the rig floor at 0935 h, ending operations in Hole U1555F.
A standard RCB coring bit was made up with the bottom-hole assembly and deployed. Coring in Hole U1555G began at 1620 h with the aim of recovering material for engineering testing as well as the science objectives of postponed Expedition 395. We drilled ahead through the sediment section to 168.6 m DSF and deployed the first core barrel. The day ended while cutting the first core at the sediment/basement interface.
Daily Science Report for 10 August 2020
Location: Hole U1555F (60°13.686′N, 28°30.021′W; water depth 1523 m; proposed Site REYK-13A)
Science Update: For the sixth drilling test of Expedition 384, we kept drilling ahead through the sediment section in Hole U1555F with a wash barrel. This test is aimed at assessing the basalt coring performance of one of the PDC coring bits that were acquired several years ago but never deployed. At 0415 h, basement was tagged with the bit at 176.3 m driller’s depth below sea floor (DSF). The wash barrel was retrieved and basement coring began. Cores U1555F-3R through 7R advanced a total of 7.4 m and recovered 5.17 m (70%). The recovery consisted of nicely cut basalt pieces up to 35 cm long. However, we retrieved the core barrel after average advances of just ~1 m because the rate of penetration was very low. At the end of the day, the bit was at 184.2 m DSF.
Daily Science Report for 9 August 2020
Location: Hole U1555F (60°13.686′N, 28°30.021′W; water depth 1523 m; proposed Site REYK-13A)
Science Update: Drilling in Hole U1555E for the fifth test, using the 12¼ inch TCI bit without a mud motor, reached the maximum bit depth of 290.6 m driller’s depth below seafloor (DSF) at 0300 h. The next two h were spent working tight hole conditions, circulating high-viscosity mud sweeps, pulling the pipe 30 m off bottom, and attempting to get back to bottom without success. We terminated drilling and retrieved the drill pipe. The bit cleared the rig floor at 1020 h, ending operations in Hole U1555E.
The next test was dedicated to the first deployment of one of the PDC coring bits that were acquired several years ago but never used. The PDC RCB bit and bottom-hole assembly were made up and deployed, and coring in Hole U1555F began at 2200 h. Core U1555F-1R was an attempt at establishing the seafloor depth; it recovered 2.5 m of sediment, which resulted in a calculated water depth of 1523 m, 7 m deeper than the PDR computed depth used so far at this site. After the recovery of this first core we drilled ahead through the sediment section for the rest of the day.
Daily Science Report for 8 August 2020
Location: Hole U1555E (60°13.679′N, 28°29.883′W; water depth 1516 m; proposed Site REYK-13A)
Science Update: Drilling for the fifth test with the same 12¼ inch TCI bit used for the second test several days ago, but without a mud motor, continued throughout the day, advancing the bit from 193.3 to 276.9 m driller’s depth below seafloor (DSF).
The technical staff prepared the laboratory for the igneous rock cores expected to be recovered within a few days. Analysis of the data collected at Site U1554 for the core orientation test is in progress, and so is the preparation of reports.
Daily Science Report for 7 August 2020
Location: Hole U1555E (60°13.678′N, 28°29.884′W; water depth 1516 m; proposed Site REYK-13A)
Science Update: Drilling for the fourth test with the 12¼ inch PDC bit and mud motor continued until 0545 h when failure of the mud motor was indicated by the loss of pressure. The depth reached with the PDC bit was therefore limited to 222.9 m driller’s depth below seafloor (DSF), a basement penetration of ~34 m. The drill string was retrieved and the bit cleared the rig floor at 1040 h, ending Hole U1555D.
The fifth drilling test aims at advancing the bit that has performed best so far to its performance limit. We altered the test plan slightly by running the TCI bit used for the second test rather than the third, brand new bit, and by doing so without a mud motor to preserve the second mud motor aboard for upcoming operations. This will provide additional information about running the TCI bit with and without a mud motor.
The TCI bit and bottom-hole assembly were made up and deployed, and drilling in Hole U1555E began at 1645 h. The top of the basement was encountered at 191.8 m DSF. At 2400 h we had reached 193.3 m DSF.
Daily Science Report for 6 August 2020
Location: Hole U1555D (60°13.680′N, 28°29.902′W; water depth 1516 m; proposed Site REYK-13A)
Science Update: Deployment of the drill string with the 12¼ inch PDC bit and mud motor for the fourth drilling test was completed and drilling in Hole U1555D began at 0245 h. The top of the basement was encountered at 0800 h, with the bit at 189.0 m driller’s depth below seafloor (DSF). The remainder of the day was spent drilling ahead and by 2400 h the bit was at 217.6 m DSF.
Daily Science Report for 5 August 2020
Location: Hole U1555D (60°13.680′N, 28°29.906′W; water depth ~1516 m; proposed Site REYK-13A)
Science Update: Drilling in Hole U1555C with the 12¼ inch TCI bit, Rhino XS hydraulically expandable reamer and mud motor, continued until 1045 h, when the underreamer had reached 20 h of operation and the bit was at 225.8 m driller’s depth below seafloor (DSF). The drill string was retrieved and cleared the rig floor at 1745 h, ending the third drilling test and operations in Hole U1555C.
From 1930 h to 2400 h, the crew made up a 12¼ inch PDC bit and mud motor, assembled the bottom-hole assembly, and began to deploy the drill string for the fourth drilling test of the expedition.
Daily Science Report for 4 August 2020
Location: Hole U1555C (60°13.682′N, 28°29.932′W; water depth 1516 m; proposed Site REYK-13A)
Science Update: For the third test, the rig floor crew continued making up the 12¼ inch TCI bit with the Rhino XS, 12¼ inch to 14½ inch hydraulically expandable reamer and the mud motor. A flow test confirmed expansion of the reamer at 45–50 strokes/min. The drill string was deployed and drilling in Hole U1555C began at 0645 h. At 1000 h, the pumping rate was increased to 60 strokes/min to expand the cutting blocks of the reamer, with the bit at 130.6 m driller’s depth below seafloor (DSF). At 1225 h we reached the top of the basement at 186.6 m DSF. At the end of the day, the bit was at 206.1 m DSF.
Daily Science Report for 3 August 2020
Location: Hole U1555C (60°13.681′N, 28°29.927′W; water depth 1516 m; proposed Site REYK-13A)
Science Update: We continued drilling in Hole U1555B with the 12¼ inch Kymera hybrid bit from 199.0 m driller’s depth below seafloor (DSF). At 1600 h and a bit depth of 210.8 m DSF, we decided to terminate drilling based on the low rate of penetration (<1 m/h) over 6 h. The drill string was retrieved and the bit cleared the rig floor at 2225 h, ending Hole U1555B operations. The Kymera hybrid bit returned intact but showed significant damage.
For the third test, the rig crew began making up a 12¼ inch TCI bit with a Rhino XS, 12¼ inch to 14½ inch hydraulically expandable reamer (Schlumberger), the mud motor, and the bottom-hole assembly.
Final measurements and observations continued in the Core Laboratory on Site U1554 cores.
Daily Science Report for 2 August 2020
Location: Hole U1555A (60°13.682′N, 28°29.944′W; water depth 1516 m; proposed Site REYK-13A)
Science Update: We continued waiting on weather until 1200 h, when the heave became consistently safe for operations to continue. Deployment of the drill string with the second test bit, a 12¼ inch Kymera hybrid bit, was completed and drilling in Hole U1555B began at 1400 h. The sediment was penetrated at the same controlled rate of ~40 m/h as was done in the first test with the TCI bit. At 2030 h we encountered the hard basement formation at 186.6 m driller’s depth below seafloor (DSF). By the end of the day we had reached 199.0 m DSF.
Routine split core measurements of the Site U1554 cores were completed except for the magnetic remanence measurements, which are carried out very methodically for the core orientation testing objective.
Daily Science Report for 1 August 2020
Location: Site U1555 (60°13.682′N, 28°29.949′W; water depth 1512 m; proposed Site REYK-13A)
Science Update: We completed the retrieval of the drill string by 0245 h. For the second bit test, a 12¼ inch hybrid bit was assembled with a mud motor and flow tested. The bottom-hole assembly was made up and the drill string was deployed to 1426 m below the rig floor by 0915 h. Wind and heave had picked up to levels unsafe for rig operations and the rest of the day was spent waiting on weather.
The IODP JRSO staff continued Site U1554 core characterization with section half and discrete sample measurements.