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The Blow-Out-Preventer (BOP) for the Chikyu riser drillingAugust 8, 2012

One of the major characteristics of the Chikyu is the riser-drilling system. The blow-out-preventer (BOP) plays an important functional role in the riser-drilling operation, which has functions that controls the pump pressure of circulation drilling mud, monitors/controls the borehole pressure, and prevents the potential explosion of deep natural gas or fluids. The weight of BOP is approximately 380 tons and the height is 14.5 meter (see the photo). The BOP is connected with the multiple riser pipes, which is also very large; a riser pipe is 27 meters in length and 50 cm in diameter. The riser pipe will be connected each one by one on the drill floor, landing the BOP on the well head at 1180 meters in water depth. If we set up the all BOP and riser pipes down to our target water depth, the total weight will be over 1000 tons!! Chikyu is big enough and enables to do it.

The blow-out-preventer (BOP) for the riser drilling is ready to go down from the moon pool on the Chikyu to the deep seabed.

After the departure from the port of Hachinohe, the drilling team on the Chikyu has been working very hard for the preparation of the BOP installation and running, for which all the safety and regulation tests such as pressure and control function are carried out on the ship. The preparation is crucial for all the planned operations. Because it is difficult to be done in the deep-sea, it needs to be completely done on the ship before we start drilling. Today, we have finally completed the preparations and pressure test and now I see the BOP connected to the bottom riser pipe is placed in the moon pool :-)

Due to the preparation, the current status is approximately 6 days-behind of the original operational plan. However, we will modify the drilling program by directly using 17-1/2 inch drill bit instead of 10-5/8 inch bit (see: operation sequences at, which will make the drilling speed much faster and recover several days.

Shipboard scientists are now almost ready and very much looking forward to having the samples on board. During the initial phase of drilling down to 1225 meter in depth, on-line/on-time geochemical analyses of the circulating mud-gas (natural gas) in the newly developed mud-gas geochemistry lab, as well as sedimentological, fossil-based paleontological, (bio-) geochemical and microbiological analyses of the drilling fluids and cuttings during the riser drilling, will be carried out. Most of these related to the riser drilling are in fact the first attempt in the scientific ocean drilling that has a half-century of the history.

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Scientists onboard Chikyu by helicopterJuly 31, 2012

The shipboard scientists of Expedition 337 from world nations finally met together in Hachinohe. We enjoyed extremely fresh local seafood and some nice Japanese beer/sake last night, and talked many things about the future dream or family. Chikyu is a complete "dry" ship, so we are NOT allowed to drink alcohols on Chikyu for 2 months... we thank the warm hospitality of Hachinohe.

The weather on July 31 is fine, almost perfect for the helicopter flight. The helicopter boarding is a kind of exciting events during this expedition since it will be the first time for many shipboard scientists. It seems that many scientists are surprised by the bigness of Chikyu, but more surprises will show up from now on.

On the vessel, preparations for the riser drilling are generally going smoothly, the drilling team have already retrieved the borehole cap and set some transponders. Scientists will have a kick-off meeting today and start preparing many things for the first core sample on deck.

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DepartureJuly 26, 2012

The scientific deep sea drilling vessel Chikyu has departed from the port of Hachinohe, now heading to IODP Site (formally C9001) that is approximately 80 km distant from Hachinohe. Most shipboard scientists of Expedition 337 will be onboard on July 31 by the helicopter transportation. The drilling team onboard has already started many preparations for the riser-drilling, including the blow-out-preventer (BOP), ROV, transponders and riser pipes. Lab technical staff are also busy for preparing analytical stuffs.

Co-chief scientists, expedition project manager (EPM) and curators are working on many sample requests from both shipboard and shore-based scientists and planning the sampling schemes and core flows in the lab on Chikyu. I very much look forward to being onboard Chikyu with our scientific team members in a few days!

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