William Larsen

GULF OIL SPILL; DON'T SPILL THE OIL

This Gulf Oil spill is really making me upset on several fronts. First the technical aspects are criminal. A company decides to drill for oil in 5,000 feet of ocean. On land, the question asked is what is done to contain spills or blow outs, fires, etc. At sea, what were the potential problems? As an engineer, I know that submarines do not go below 2,000 feet or if they do not much more, definitely not 5,000 feet. There are small submersibles that go that deep.

Question one is how do they put equipment on the sea floor? Do they weld under water? Do they use fasteners under water? Do they just use mechanical fit ups to make seals? How on earth do they lay miles of pipe down 5,000 feet?

Looking at the blowout preventer and the associated pipe, it seems to be on top of the sea bed. Clearly they did not lower this as a single unit.

Three companies are involved BP, Transocean and Halliburton. Deepwater Horizon is a floating drilling platform owned by Transocean. Halliburton was the brains behind the drilling and provided the necessary expertise. British Petroleum leased a floating oil rig. BP hired Halliburton to drill the well. BP held the lease for the section of ocean floor.

One employee alleges that rubber was found in core samples after a test of the emergency blowout preventer. During the test an operator error caused a section of pipe to be extracted through the rubber sealed blowout preventer. The rubber found in the core sample was disregarded by others.

Not knowing much about drilling, but have experience with pumps, I wonder why we have such a problem.

THE PROBLEM:
Broken 21 inch diameter pipe located 5,000 feet below the ocean surface on the sea floor. It appears to be jagged and not vertical. The oil seems to be exiting the pipe and makes a directional change upwards. The oil is under pressure which causes the oil to seek an outlet (broken pipe).

ATTEMPTED SOLUTIONS:
BP has tried pumping mud into the blow out preventer. From all the diagrams I have seen, the inside piping is smooth and straight. I find that pumping mud into this unit with an unblocked exit un promising at best. The mud may prevent the oil from escaping, but as soon as the mud is consumed, the oil will no longer be blocked by the mud.

BP then tried a junk shot with the intention of blocking, stopping up the exit. Again they used gulf balls and other objects. What I find interesting is all the objects seemed to be round which means they would not tend to lodge against each other and form a mechanical blockage. Furthermore, since the outlet is open and the oil has created a good lubricant on the inside of the pipe walls, I would think the chances of a frictional interference slim.

MY TOUGHTS:
My first thought was to lower 5,000 feet of large diameter culvert down over the exit. It would be difficult to pump oil up a hose, pipe or tube and keep it located close to the exiting oil let alone collecting the majority of the oil. The concept was to contain the oil and channel it under low pressure in respects to the sea water pressure up to the surface where it could be pumped into ships. Clearly the oil is leaking. Clearly the oil is rising. Clearly the oil goes with the current. Therefore, why fight the buoyancy aspect of the oil? Clearly the methane in the oil when it contacts sea water is causing a chemical reaction and freezes creating ice. How much ice? How large a chunks are we talking about? A diameter large enough could channel the oil to the surface, at least containing it to a smaller area.

My second thought was try and plug the outlet. The pipe is open and oil is gushing out. The diameter is 21 inches or 346 sq inches. If you were to attempt to block the exit, how close could you get to the outlet before the pressure would keep you from getting any closer? Maybe you could get within six inches of the outlet with a flat plate? This would not stop the flow, but it may allow the junk shot to work by creating a choke point of six inches not the 21 inch diameter outlet. A better idea would be to not block the outlet with a solid, but to put a titanium net, mesh, screen, lattice work or, grate at the outlet and then use the junk shot. The junk shot would have to be pieces larger than the mesh, grate or what ever at the outlet in order to capture/trap it. This would then begin to block the outlet. Clearly as the oil is blocked the pressure inside the pipe would rise. Design parameters of the pipe would have used total blockage using the blowout preventer and there should be no risk of a pipe rupture.

My third thought was to use under water robotics to saw a clean edge on the outlet of the pipe. Clamp/weld/bolt a coupling to the outside of the pipe with a new blow out preventer open. This would be needed so that the oil would not dislodge the blow out preventer from being secured to the broken pipe. Once secured, close the new blow out preventer.

If no one who is in the business of drilling for oil 5,000 feet down has thought about these and come up with reasons why these would not work, then these people need to find a new line of work. I am not an expert in oil drilling, but I have a lot of experience in fluid flow. I know how hard it is to block a raging torrent of water. The only way I found to control this type of situation was to build two bastions on either side and lower a gate between them. You can build the supports outside the confines of the flow and once secured, can lower the gate. To me the oil spew is a similar problem.

Who is at fault in my opinion is all three. I think all three companies will cease to exist. This oil spill will cost the sum total of BP’s assets. BP is larger than Transocean and Halliburton combined. If you wanted to make money, selling these companies short might make you very wealthy.

posted by William Larsen @ 4:52 PM