BP Gulf Oil Leak Well-Head Repair … an anthology II

So … last night we left off at the point where BP was removing the flange bolts using a hydraulic socket wrench.

View of the hydraulic socket tool on one of the flange bolts

Notice the bolt to the right of the one with the wrench (not the larger object directly adjacent to the bolt the socket is on … I believe that is an alignment pin, but certainly not a bolt head. I’m referring to the second object to the right of the bolt that the socket is on). It appears the flat surfaces have at some point been damaged. The image below provides a better view:

Bolt on the right shows damage to a couple of its hex surfaces

Not to worry! Just go to your trusty tool box and bring out the Dremal rotary tool … an industrial strength Dremal if I do say so!

Industrial strength Dremal rotary tool being used to grind burrs off of hex bolt in image on the left (click on image to see an enlarged version)

Below is a second view of the grinder seen from both ROV cameras:

Grinder seen from both ROVs (click image to enlarge)

The next image shows the hydraulic socket wrench loosening the now-cleaned bolt:

Socket on bolt that had the burs removed with grinder

Same view as the last, but from both ROVs (note the polished surface … as a the result of grinding, of the bolt below the socket in the image from ROV 1):

Damaged bolt removal seen from both ROVs (click image to enlarge)

ROV 1 now begins to remove all the loosened bolts:

ROV 1 using one of its mechanical arms and "hand" begins to remove the loosened bolts

The “hand” at the end of the arm is positioned directly above each bolt and then rotates counter-clockwise, unscrewing each bolt.

Bolt almost removed from flange

I was surprised that as each bolt was removed, the ROV would back away from the stack and move to a shelf located somewhere lower on the stack and drop each bolt on the shelf, rather than just drop the bolts to the ocean floor. Keep your work space tidy!!

Meanwhile, in the next image ROV 2 breaks out the trusty rotary wire brush and begins cleaning the surface of the outer flange:

Rotary wire brush cleaning the outer flange surface

It is pure speculation on my part, but I suspect that the Flange Overshot Removal Tool (FOLT), designed to remove the damaged flange, is designed with relatively close tolerances. BP cleaned the outside of the flange to make sure there are no large burrs or other obstacles on the flange that could inhibit the placement of the FOLT, shown below:

Flange Overshot Removal Tool ... used to remove the flange

Wire brushing continues to clean the entire outer surface of the flange:

View of wire-brushing operation from both ROVs (click image to enlarge)

I mentioned the “tool box: earlier. Below is a shot of one of those tool boxes:

Tool box

Note all the different colored rope loops with different tape markings; a very simple and clever way of identifying different tools IMHO. I’s say these guys may have done this type of thing once or twice before Below is a second view of the same tool box:

Another view of one of the tool boxes

At this point it’s almost midnight Saturday evening in the Gulf and the activity that I can see via the various ROV cameras is slowing down, so I decide to call it a day and go to bed. As it turned out, BP was apparently able to remove the flange around 12:30 or 12:45, so I missed that operation completely.

In the next post I’ll pick up the operation that began the next morning to install the Flange Transition Spool, seen in the image below:

Flange Transition Spool being tested

Related posts:

1. BP Gulf Oil Leak Well-Head Repair … an anthology III
2. BP Gulf Oil Leak Well-Head Repair … an anthology
3. BP Gulf Oil Leak Well-Head Repair … an anthology part IV – UPDATED
4. BP Gulf Oil Leak Well-Head Repair … an anthology part V – UPDATED