5 weeks 2 days
Retrieving the CORK
Submitted by Adam Klaus on Sat, 09/24/2011 - 09:30
Hole 395A was first drilled in 1975, and on Friday, we successfully retrieved the CORK observatory that was installed in 1997 on ODP Leg 174B (14 years ago). Here’s a look at part of that process.
First, the drill floor guys picked up the CORK pulling tool and started preparing to lower it to the seafloor. They then picked up some drill collars (very thick-walled, heavy, orange pipe)—these make lots of noise as they pull them up from where they are stored on the main deck to the rig floor. The heavy drill collars at the bottom of the drill string will keep it in tension (it is weak in compression = bad!).
Once the CORK pulling tool and drill collars were lowered through the moonpool, we started adding stands of drill pipe (a stand is 3 joints of drill pipe and is 30 m long). The first time we pick up the stands of drill pipe, it takes a bit longer than normal—they have to “strap and rabbit” the drill pipe [“strap” = measure the length of every piece of pipe; “rabbit” = pass a tool through the inside of each piece of pipe to make sure there’s nothing blocking it]. The stands are added one after another until the pipe reaches the ocean floor, which is at about 4490m. Since each stand is 30m long, that’s about 150 stands of pipe that have to be screwed together! Watch the video below to see the guys fitting the stands together…a process we call “Tripping Pipe.”