Oil + Water
Eleven dead. More than four months to plug the well completely. Five million barrels of oil polluting the ocean. Oil industry expert and geophysicist Roger N. Anderson talks to Columbia Magazine about the technical aspects of the Gulf of Mexico disaster.Interview by Michael B. Shavelson Published Fall 2010
COLUMBIA MAGAZINE: Why is there so much oil under the Gulf of Mexico?
ROGER N. ANDERSON: The Mississippi and the other great rivers that carry sediment from the Rocky Mountains have been dumping rich organic mud into the Gulf for millions of years. The Gulf, which is really a big hole, was made 60 to 80 million years ago by plate tectonics and the initial rifting of the Yucatán and Cuba off North America as the continents responded to the big collision that made the Rocky Mountains.
COLUMBIA: It sounds as though the Gulf is a 580,000-square-mile compost heap.
ANDERSON: But without the abundance of oxygen in the sea bottom. The Gulf is a place where water circulates with difficulty, and that prevents the oxidation of organic material as it spills into this ocean basin. If the material oxidizes, it loses its organic energy — oxygen combines with hydrogen and carbon — and the game is over. No oil or gas.
COLUMBIA: Summarize what happened on BP’s Deepwater Horizon this past spring.
ANDERSON: BP started drilling the Macondo well on February 15 about 40 miles off the southeastern coast of Louisiana. This was an exploratory well; the rig was in 5000 feet of water and was drilling through a further 18,000 feet of seabed. By March the rig was in serious trouble. It was taking what are called kicks — blobs of natural gas forcing their way up the drill pipe and burping onto the rig floor. Those kicks were coming every few days. It’s the energy from the buoyant mass of oil and gas trying to vent to the surface. (Although kicks are unwanted on the surface, they can be a good sign in the oil business, because the bigger these pressure pulses, the larger the oil and gas reservoir.)
COLUMBIA: How should crews have reacted to the kicks?
ANDERSON: Primarily by keeping the pipe filled with heavy drilling mud, which is a special mixture of heavy clays that is much denser than seawater. A gallon of water weighs about 8.9 pounds. A gallon of this drilling mud weighs up to 22 pounds.
COLUMBIA: The high density of the mud keeps the natural gas and oil down in the reservoir
ANDERSON: Right, but the mud is expensive, and it appears that BP was trying to save money. They were also rushing to finish the well, which had been fighting them the whole time, making them weeks behind schedule. The people on the rig called it the “Well from Hell.” On the morning of April 20, the crew from Transocean (the owner of the rig), over the strong objections of their own drilling superintendent, was ordered by BP to take the heavy drilling mud out of the drill pipe and replace it with seawater. That was the triggering event that allowed the gas and oil to blow out onto the Deepwater Horizon rig floor — then a random spark ignited a tremendous explosion. The rig sank, allowing the free release of the pressure and the energy of all that oil and gas into the ocean. The rest is history.
COLUMBIA: We are all now familiar with the term blowout preventer or BOP. What is it, and what went wrong?
ANDERSON: The blowout preventer is a powerful hydraulic device that clamps the riser pipe shut in case of just such an uncontrolled kick. It is the thing that saves you when everything else has failed — thus the name. The blowout preventer had been giving Transocean trouble for a month before the explosion because of hydraulic leaks and electronics problems. The key to any hydraulic system is that if it leaks, it doesn’t have the power of compression that it needs to function properly. Now that the Deepwater Horizon’s BOP has been returned to the surface for autopsy, we will learn just what was leaking, and where.
Another problem was that the blowout preventer was apparently too small. As BP and the deepwater oil industry in general migrated to deeper and deeper water to find new oil and gas, they had to use stronger and stronger drill pipe and casing, and the BOP was no longer sufficiently strong to slam shut in this emergency.
COLUMBIA: Was this a matter of loose oversight? If the Deepwater Horizon had been under another country’s jurisdiction, might this disaster have been prevented?
ANDERSON: Those kicks would have been a giant red flag anywhere else in the world.If this well had been drilled in the North Sea, for example, the British government would have shut it down a month before the blowout. And they would have had hearings on what to do about it. The government probably would have replaced the blowout preventer with a bigger one and let them keep drilling.
In the North Sea on July 6, 1988, there was a gigantic explosion on an Occidental Petroleum production platform called the Piper Alpha. That tragedy killed 167 people. As a Stanford University report on the incident later said, “It was caused by a massive fire, which was not the result of an unpredictable ‘act of God’ but of an accumulation of errors and questionable decisions.”
The report attributed the blame to the organization, its structure, procedures, and culture. There were flaws in the design, along with insufficient redundancies, and “misguided priorities in the management of the tradeoff between productivity and safety.”
Because of the disaster, laws and regulations were passed in the United Kingdom to increase the oversight, strength, and security of oil platforms.
COLUMBIA: In the United States, the regulatory agency responsible for well safety was the Minerals Management Service. Why was the MMS ineffective?
ANDERSON: The MMS was part of the Department of the Interior. Its job for the last 30 years had been to increase revenue by pushing for more and more oil and gas production. Oil and gas production make up a large percentage of the government’s revenue. That and the IRS are the two big moneymakers that feed everything from our military to Medicare. Even six months of the deepwater drilling moratorium enacted by the Obama administration will have an impact on our deficit in a couple of years. In June, the MMS was renamed the Bureau of Ocean Energy Management, Regulation, and Enforcement.