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November 26th 2005
D/V CHIKYU succeeds in acquiring the 1st core! Back to list
On November 26th 2005, D/V CHIKYU carried out her first coring operations using the Hydraulic Piston Coring System (HPCS) 90km northeast of the SHIMOKITA peninsula, Japan. Acquisition of the first 9.5 m core (geological sample) from the seafloor at 1,200 m water depth was successful.

This is the first sample acquired by D/V CHIKYU.



D/V CHIKYU left HACHITARO Wharf, HACHINOHE Port at 10:00 a.m., November 17th and headed for the first coring site. The temperature was 6 degree C at noon with a glorious view of snow-covered mountains. CHIKYU staff devoted their time to equipment, measurement tools and data system set-up. An abandon ship drill was carried out on November 18th, and evacuation and safety boat training was conducted.

The weather was comparatively moderate, and the vessel hardly rolled while sailing to the coring site off the SHIMOKITA peninsula.

22 Nov, Tuesday, Fine but Cloudy
10:00 a.m.

Drilling crew and Lab. Staff, including the Director-General, embarked from the last service boat before setting sail for the coring site.

15:00 p.m.

Sampling meetings were held far into the night with the Curator (Sample manager), onboard scientists and Lab. staff in order to confirm analysis methods and procedures.

19:00 p.m. D/V CHIKYU headed for the coring site.
24:00 p.m. Arrived at the coring site. The vessel began Dynamic Positioning operation.
Wind speed was 10 m/s, and wave heights were 1.0 meter on the following morning. D/V CHIKYU was able to keep her position to 5.0 meter under these conditions.
It began to rain at night and wind increased to 15m/s, with no impact on the vessel.

23 Nov, Wednesday, Fine but Cloudy
07:30 a.m. CHIKYU crew started work this morning by powering up the piperacker elevator and installing the lifting lug.
10:00 a.m. The coring bit was assembled.
13:00 p.m. The coring unit (connected core barrel and drill collar on the core bit) was lowered to a depth of 28 meters.
15:00 p.m. Hydraulic pressure was bled off and inserts were swapped into the elevator.
18:00 p.m. The coring assembly was lowered to a depth of 180 meters. Lab. staff were keeping stand by onboard.

24 Nov, Thursday, Cloudy occasionally Rain
08:00 a.m. The coring unit was lowered to 445m. Many Pacific sauries could be seen in the Moon Pool. (of course fishing is strictly prohibited). Safety helmet, safety glasses and safety shoes are required on deck, and no activity can take place without express permission of the proper manager.
15:00 p.m. Coring unit lowered to 1,180m.
Rollers on the hydraulic Roughneck (equipment used to connect/disconnect drill pipes) were adjusted
16:00 p.m. HPS (Power unit) was assembled
Coring unit reached and confirmed the seabed, at 1,215 meters depth

Drill pipe raised to 1,192m, pumping carried out to circulate sea water through drill string.

17:00 p.m. Sinker bar platforms and drillfloor seal extended in order to work aloft. Retrieved wiper seal plate

Onboard staff and land-based teams were excitedly waiting for the first core. the drill team proceeded carefully, step-by-step.

25 Nov, Friday, Fine but Cloudy
07:30 a.m. Temperatures consistently below 10 degree C. Drill crew continued activity.
Sinker bar (plummet connected to top of the inner core barrel), wire line and wiper were installed, HPS mode maintained
08:00 a.m. Investigated wireline BOP
09:00 a.m. Investigated pressure drop on Drawworks. Air Dryer worn out, #2 dryer rotated in.
14:00 p.m. Made up stand #30 to HPS. Ran Sinker Bar through HPS.
15:30 p.m. Installed Inner Core Barrel assembly.
17:00 p.m. Set up on coreline winch to lower inner barrel down to drill head

Today was the birthday of Captain Ichiyama, and a small party was held in the Mess Room during dinner.
The first coring operations are just a day away.

26 Nov, Saturday, Cloudy
06:00 a.m. Temperature 8.9 degree C, wind speed 18.5 m/s, current speed 1.4 kts south-southwest
07:00 a.m. Drilling crew confirmed and evaluated equipment status, coring operations begin.
08:00 a.m. Installed Inner Core Barrel assembly and connected sinker bar assembly.
09:00 a.m. Lowered core bit to 1,210m, ran Inner Barrel to 1,125m.
Tension on core barrel wire lost, pulled back to obtain 700 kg tension.
10:00 a.m. Closed Wireline BOP seal rams. Begin coring. Pressure up and shear pins.

Shoot the Inner Core Barrel.

10:40 a.m. Pulled up the Inner Core Barrel from drill head below seafloor, broke connection.
Announced by paging from Drill Floor, "Congratulation, first core on deck!"

Everyone cheered and congratulated each other.
First sample recovery was 105% (due to expansion of core material).
  Core-liner was transported to Core Cutting Area using conveyor. Director-General Taira shook his fists again and again - a victory dance!
  Sediment smelled strongly of chemicals, and the core expanded out the bottom of the core, many small holes were drilled into the core liner to degas and decrease internal pressure, an automatic Mud-Noodle maker.

After degassing, the core-liner was measured and cut into 1.5-meter-long sections from 9.0 meters along the core, and these sections were transported to the Core Processing Deck.

  The cores taken into Core Proc. Deck were assigned a unique ID. After confirmation of ID, the cores were immediately analyzed by X-CT. X-CT images were displayed in the Composite Log Viewer (CLV), one of components of J-CORES, and show the presence of show several thin, high-density layers, probably ash layers. It was very good location to install the conductor pipe for the riser drilling operation in next year.
  After getting the first core, 5 more cores were collected. Everyone, from drill crew to laboratory staff to galley crew worked late. Results from the first coring operations were satisfactory in terms of core recovery, in terms of vessel and equipment operations, and in terms of crew performance.


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