Behind the Science – Adam’s chronicle: searching for the reentry cone

JOIDES Resolution is on the site for Hole U1499B. We want to reach the basement but we know from Hole U1499A that we would have to pass through some sediments. So we put a casing (see previous post) for stabilizing the material around the drilling system.  Afterward we put a reentry cone in this hole for several reasons, but basically because we want to find the hole again after having disconnected the string of pipes.

But it is not always easy to find the reentry cone in the sea floor. Let’s read what just happened from the words of our Expedition Project Manager, Adam Klaus.

Unfortunately working at sea always is interesting – although sometimes challenging! The camera was down and we started searching for the Hole 1499B reentry cone at around 0200 this morning. When I woke up and turned on the monitor in my room, all I saw was the end of the bit above the seafloor. I turned the channel to the rig floor – pipe not rotating…..hmmmmmm, not what I expected to see.

Most of the time it takes from 5 to 3o minutes to find and reenter a hole -but not always! When they couldn’t immediately locate the reentry funnel, the DP operators (Dynamic Positioning) started an expanding 5 m spiral grid search. When I got up at around 0515, that search was done and they started filling it in with diagonal lines… Still no luck. I saw Steve get up – nervous again…. Then they raised the camera  frame and used the pan/tilt to look farther out and eventually we saw the reentry funnel (phew…). Then a bit later the DP operators were able to get the bit over it and the driller lowered the bit into the hole (YEAH!). It does appear that the funnel has settled a little bit into the cuttings mound or uppermost seafloor but is also plainly visible – so everything should be fine for continued RCB/logging operations in this hole!

I won’t go into the various bad things that have happened in the past – if you want to know about those painful experiences , you are welcome to ask. However, just be happy it’s working out for us!