On the evening of April 29, the first oil from the
British Petroleum Horizon disaster started washing ashore near the mouth of the Missippi River. This oil spill is threatening to eclipse even the Exxon Valdez in the magnitude of environmental destruction. The following text is adapted from an e-mail that was sent to me documenting the demise of the the BP Horizon drilling platform:
On the night of April 20, the BP Deepwater Horizon semisubmersible drilling rig caught fire in the Gulf of Texico (oops, Mexico) off the coast of Louisiana. The rig burned for two days and then sank in 5,000 ft of water. An estimated 5,000 barrels of oil per day are spewing into the Gulf and eleven workers remain missing and are presumed dead. The rig was owned by
Transocean, the world’s largest offshore drilling contractor and was contracted through the year 2013 to BP. BP was working on their
Macondo exploration well approximately 41 miles offshore Louisiana on Mississippi Canyon block 252 when the fire broke out. The dry lease of the rig cost BP about $500,000 per day and the full drilling spread, including helicopters, support vessels, and other services, increased the estimated daily operational costs to close to $1,000,000. The rig cost about $350 million to build in 2001 and, according to a recent
Wall Street Journal article, has an estimated replacement cost of $560 million today.
This rig represented the cutting edge of drilling technology. It was a floating semisubmersible rig, capable of working in up to 10,000 ft water depth. This type of rig is not moored; It does not use anchors because it would be too costly and too heavy to suspend this mooring load from the floating structure. Rather, a triply-redundant computer system uses satellite positioning to control powerful thrusters that keep the rig on station within a few feet of its intended location, at all times. This is called Dynamic Positioning.
The rig had apparently just finished cementing steel casing in place at depths exceeding 18,000 ft. The next operation was to suspend the well so that the rig could move to its next drilling location, the idea being that a rig would return to this well later in order to complete the work necessary to bring the well into production. It is thought that somehow formation fluids – oil /gas – got into the wellbore and were undetected until it was too late to take action. With a floating drilling rig setup, because it moves with the waves, currents, and winds, all of the main pressure control equipment sits on the seabed – the uppermost unmoving point in the well. This pressure control equipment – the Blowout Preventers, or ‘BOP’s” as they’re called, are controlled with redundant systems from the rig. In the event of a serious emergency, there are multiple Panic Buttons to hit, and even fail-safe Deadman systems that should be automatically engaged when something of this proportion breaks out. None of them were aparently activated, suggesting that the blowout was especially swift to escalate at the surface.
The flames were visible up to about 35 miles away. Not the glow – the flames. They were 200 – 300 ft high. All of this will be investigated and it will be some months before all of the particulars are known. For now, it is enough to say that this marvel of modern technology, which had been operating with an excellent safety record, has burned up and sunk taking souls with it. The well still is apparently flowing oil, which is appearing at the surface as a slick. They have been working with remotely operated vehicles, or ROV’s which are essentially tethered miniature submarines with manipulator arms and other equipment that can perform work underwater while the operator sits on a vessel. These are what were used to explore the Titanic, among other things. Every floating rig has one on board and they are in constant use. In this case, they are deploying ROV’s from dedicated service vessels. They have been trying to close the well in using a specialized port on the BOP’s and a pumping arrangement on their ROV’s. They have been unsuccessful so far.
Specialized pollution control vessels have been scrambled to start working the spill, skimming the oil up. In the coming weeks they will move in at least one other rig to drill a fresh well that will intersect the blowing one at its pay zone. They will use technology that is capable of drilling from a floating rig, over 3 miles deep to an exact specific point in the earth – with a target radius of just a few feet plus or minus. Once they intersect their target, a heavy fluid will be pumped that exceeds the formation’s pressure, thus causing the flow to cease and rendering the well safe at last. It will take at least a couple of months to get this done, bringing all available technology to bear.
The situation is quickly becoming an ecological disaster and there is no apparent quick fix to stop the leak. The most optimistic hope is that it could somehow bridge off downhole but many experts are predicting several months of unabated flow and with hurricane season fast approaching the full scope of the disaster is only now becoming appallingly clear. Maybe it is not such a good idea to drill for oil so close to our valuable beaches and fisheries.
The photos that follow show the progression of events over the 36 hours from catching fire to sinking.

The Oil Begins to Spread Soon After the Sinking on April 22 (Ironically, this was Earth Day)