16 July 2004

CASING SUCCESS!!! and HELICOPTER RIDE

FINALLY!!! We were able to set the 10 3/4-inch casing. This doesn’t guarantee that we will get core samples, but we are a whole lot closer. Many people are a lot more relaxed with this news.

A helicopter came from Astoria, Oregon (USA) to the JOIDES Resolution today to bring in some important supplies for the scientists. The IODP staff arranged for Bill Crawford, Expedition Image Specialist (USA), and myself, Jonathan Rice, Teacher at Sea (USA), to fly on the helicopter to take pictures of the JOIDES Resolution from the air. What an excellent day!!!

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

We finally were able to install the 10 3/4-inch casing (yeah!). We cemented it in place and unlatched the casing running tool. The depth at which the casing hanger landed in the cone was a few meters deeper than we had originally installed it- so it is possible the cone has sunk into the seafloor a bit. I believe they used the end of the casing running tool to check the seafloor depth just after releasing- we'll have to get the exact depths tomorrow when Mike wakes up. The reason this is important is that once the CORK is installed, the valves and other critical sampling gear on the CORK head are just a little bit above the top of the reentry cone. If the cone has sunk, sediment may hinder access to these. Also, as we core deep into basement, the cuttings will continue to pile higher, potentially making the problem worse. We will likely have to do some careful depth checking with the bit when we return here after finishing Hole 1301A. The engineers are also evaluating whatever other options there may be.

While retrieving the drill string, we have been moving the ship 1 km to Hole 1026B in dynamic positioning (DP) mode cruising at ~0.75 nmi/hr (we can go a bit faster in DP mode, but we'd have to raise the DP system hydrophones). We are already over Hole 1026B (~2030)! We had to pause bringing back the drill string to "slip-and-cut" the drill line...

DRILLER's SPEAK: "slip-and-cut" simply means that we "slipped" or pulled ~115 ft off of the drill line and "cut" it off. The drill line is the very thick cable that raises and lowers the entire drill string - it can bear a LOT of weight (I think about 1,000,000 pounds or so). As this piece of cable goes back and forth repeatedly over a sheave at the top of the derrick, it is important to slip and cut the drill line periodically so that it doesn't get too worn in any one place and become weak. This is a preventative maintenance that must be done every ~4000 ton-miles (I really love that unit!!- ton-miles).

So, anyway... Once the casing running tool is back on board (should be pretty soon), we'll assemble a special fishing BHA to try to remove the mini-cone that is sitting on top of the Hole 1026B CORK. This will consist of a special piece of pipe at the bottom of the drill string that is completely closed at the bottom and has a hole drilled in one side. By pumping seawater through it and rotating the drill string, we can "steer" the pipe around down at the seafloor. Now that we can move it around, we need a way to snag the mini-cone. As I speak, the welder is down near the moonpool fabricating a V-shaped fork that will be pressed onto the CORK with the CORK between the prongs. When this is raised, it is intended to pull the cone off. This should be happening very early in the morning (about the time I get up! so some of you may miss this).

Once we are finished, we'll return to Hole 1301A, drill out the cement, check the open hole for any fill, conduct a packer hydrologic test, and then CORK the hole. Then we'll return to Hole 1301B, drill out cement, and RCB core. ESTIMATED CORE-ON-DECK COUNTDOWN: ~6 days (?)

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