Follow Dr. Katrina Edwards, as she explores the microbial life at the bottom of the Atlantic Ocean
Today we have another guest blog from Geoff Wheat (Univ. Alaska, Fairbanks)
There are 120 people aboard the JOIDES Resolution (JR) from more than a dozen countries. Some are on the ship because of the salary, some to get away from the rigors of the oil industry, some to see the world, experiencing new ports every two months and some to participate in scientific endeavors. There are as many reasons as the number of people. My reason for being here is satisfy the multi-year planning process to deploy a number of samplers and experiments within three oceanic boreholes to assess the extent of ongoing crustal alteration, constrain hydrologic properties of the crust, and assist with several in situ microbiological experiments.
This melting pot of humanity aboard the JR brings together a range of skills, all necessary for the success of the expedition. This expedition is my fifth on this ship and I’m still amazed at the capabilities offered by the crew and technical staff. There is a machine shop onboard and the ship always seem to carry the appropriate materials needed to fabricate whatever needs to be made to complete scientific objectives. What I’m really amazed with is the engineering and technical experience that makes the impossible a reality in the middle of the ocean. Over the years there have been many such examples, but I want to highlight an example from this expedition.
Earlier in the expedition we were drilling the “deep” hole into which we would place an observatory. We wanted to get below the permeable upper basement (>450 m below the sediment-basalt interface). The borehole was designed with three-nested steel casing systems. Two of these systems were deployed when the drill bit failed, leaving several pieces of the bit in the hole, effectively “junking” the hole. We had two choices; try to fish the pieces out of the hole with no guarantee of success or start all over with additional materials that we brought to satisfy several contingency schemes. Once the decision was made to start a new hole, we initiated discussions for using the “junked” hole as a possible borehole observatory.
We discussed the possibility of designing a wellhead that could be deployed by a remotely operated vehicle (ROV) during the follow-up cruise in April. We would populate the borehole with samplers and experiments that remained from this expedition. Our shipboard discussions quickly incorporated operational and engineering experts at Woods Hole Oceanographic Institution and the Monterey Bay Aquarium Research Institute. As a plan solidified, we became more confident that such a deployment was feasible and practical even with a shipping date of early February.
The plan was predicated on deploying an ROV platform. Typically this activity relies on the structure of the wellhead to release the platform from the wireline used to lower it in place. The lack of a wellhead required a new solution. Several renditions were bantered about among operational, engineering, technical, and scientific personnel. When a plan was settled on, the ships crew and an engineer began the process of modifying the platform. Within a day all of the pieces were fabricated and welded in place, meanwhile operations on the rig floor continued as they always do, making the most of the rig. The ultimate plan was to reenter the borehole with the drillstring, revise the ROV platform and bolt and weld it around the drill string, free-fall the platform and chase it with an underwater camera to make sure it did not get “hung up” and landed as anticipated. The platform landed as intended, maybe a little off center, and the drill string was removed.
We now have a cased borehole that is open to basaltic crust below that is ready for the installation of a novel wellhead. Preliminary designs for the wellhead have been sent to a machine shop in Houston and other pieces are being gathered for the deployment in April. This success story, turning a “junked” hole into a usable scientific platform was possible only because many people with a range of expertise, experience, and background worked together for a common goal. Too bad our politicians in Washington can’t similarly come together for the common good. It would be prudent if Congress acted like the international community aboard the JR. Nevertheless, we’ll see how the deployment goes in April, but I for one am confident that it will be a success.