Follow Dr. Katrina Edwards, as she explores the microbial life at the bottom of the Atlantic Ocean
I have good and bad news to report today about our operations over the past few days. Our CORK installation operations overall went extremely well – new components that we were using for these installations like fiberglass casing worked great. We wanted to use fiberglass instead of steel because it is less bio-reactive and should perturb our system less than rusty old steel pipe. And otherwise operations went, well, great.
There were several days of practically no sleep in there for me as operations go 24 hr/day continuously and I didn’t want to miss a minute. We finally got to the end of our installations when things went horribly awry. We had installed the top of the CORK assembly – the CORK top plug and well head unit, and went to install the final component of the system – the landing platform where a submersible or remotely operated vehicle (ROV) from a ship can land and perform the various operations that we plan on doing annually during visits over the next few years. Things like pumping of fluids, exchanging out experiments that are installed at the well-head. As the landing platform lowered, it got somewhat hung up on the CORK head but then finally shook loose and seated in place. Then comes time for the final operation, releasing the tool that brought the whole assembly to the seafloor – the instrument string and well head – and returning to the ship.
This is when things went wrong. We could not seem to release from the well head. Basically it involves a relatively simple maneuver of gently pressing down on the tool and twisting 90°. We tried and tried for some time and then suddenly, it appeared to release. However, when we sent the camera down to inspect, we could see that apparently the entire CORK head broke off and was still sitting in the tool. This was horribly devastating to the science party, the drillers, everybody.
What we did not know is if the instrument string that hung in the hole below the head was still there, or if it was attached to the CORK head. We began to retrieve our tool, waiting an excruciating 8 hours before we could learn anything more. When the CORK head finally came to the surface we could see that in fact there was not an instrument string attached, and that it apparently is still in the hole! We could also see that the CORK head was pretty bashed up. The umbilical lines that pipe from the subseafloor to the CORK head were broken and pointing every which way, the entire CORK body was bent – apparently a compression failure – and a region just below the well head is where the shearing took place.
So, the bad news is probably self evident from this description, but there is a silver lining to this story – the instrument string is still in what we think is a sealed (for the most part) hole. Our engineers think we have high likelihood of potentially retrieving these instruments in a few years, and plans are already underway to do this. It will of course be a more complicated procedure, to fish out our instruments from the hole using some tool that has yet to be designed by comparison to simply lifting them using the CORK head, but it is doable and that gives us some hope.
Meanwhile, if that was not enough, tropical storm Phillipe began to descend on us and we had to pretty much immediately leave the area after retrieving the CORK head to get out of the path of the storm. We are now on our way back to site, where we will immediately begin to drill for our 2 remaining holes.
The roller coaster ride continues – hoping for a bit more peaceful operations during our next steps!