3 July 2004

SCIENCE AND SHIP LIFE ACTIVITIES

We are nearing the point of putting the 16-inch casing in the hole. Next, we will be drilling a smaller hole and putting 10 3/4-inch casing, and finally… we will be ready for coring. The scientists and technicians almost have their areas ready to receive core. There is a little more time for relaxation. I have included some pictures showing what people are doing to unwind after a hard day working, and some of the science activities occurring in the labs.

Here is a partial update for today given by the Expedition Project Manager/IODP-USIO Staff Scientist Adam Klaus (USA):

“We have been assembling 16-inch casing most of the day. The casing is stored in the casing hold (a very large room underneath the pipe racker - about the size of a doubles squash court). Each piece of casing was measured before it was loaded on the ship and assigned a number - both of which are written on the outside of the piece of casing. This way we can determine which pieces to use to achieve a specific length of casing.
First, the casing has to be moved in the hold to beneath the large overhead doors to the hold. Then we have to lift it out and lay it on the center of the pipe racker that shifts it forward to the rig floor where it can be lifted up vertically and screwed together to other pieces.

Before they could start handling the casing on the rig floor we had to assemble all the tools required to be able to handle and screw the casing pieces together. The first thing we did was pick up a “cement shoe.” This is a metal piece that goes on the bottom of the casing which allows us to pump cement through the bottom of the casing without it flowing back into the casing. The cement shoe can be drilled out (see below). Then we started assembling the chosen pieces of 16-inch casing. Each piece is screwed to the previous one and welded to make sure it won't come apart. While assembling the casing, we have to stop periodically to fill the casing with water so that it won't collapse due to the water pressure (remember the cement shoe at the bottom has a one-way valve so water can't fill naturally from the bottom as it does with open casing).

To the top piece of casing we attach the casing hanger, which we will latch inside the 20-inch casing hanger inside the reentry cone.

Then we attach the casing running tool to the top of casing hanger. As we will be cementing the casing, this time we have a special tool just below the casing running tool. I forget the name…. SSR?....but I'll find out for you. We will lower the casing string to the seafloor, reenter the hole (sometime after midnight) and hopefully lower the casing with no problem until just a few meters before the casing hanger lands in the cone. At that time we will attach the cementing manifold to the top of the drill string. This allows us to introduce cement into the drill pipe while also having the ability to pump seawater. Once the manifold is in place, we will lower and land the casing string in the hole (keep your fingers crossed that it goes all the way in!). At this point, we will pump the desired amount of cement into the pipe with a “dart” just behind the cement. The dart and cement will be pumped down the pipe. The dart cleans the cement out of the pipe as it goes. When the dart passes through the “SSR??” just below the casing running tool, it causes a plug to release that follows the cement down the casing string - also cleaning cement out of the casing as it goes. The cement exits the through the cement shoe at the bottom of the casing and “u-tubes” back up the outside of the casing. When the dart and plug reach the casing shoe, it causes an increase in pressure in the drill pipe, so the driller knows that the cement has been placed where we want it. We can then release the casing running tool and retrieve the drill string.

Our next step will be to use a 14-1/2-inch tricone drill bit to drill out the dart/plug and cement shoe (which although strong, they are drillable), the cement at the bottom of the hole, and then continue into basaltic basement. This bit will be used to open up the hole into which we will install the 10-3/4-inch casing! Enough for now! Good night!”

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