Facts are fun part two: Repost. The Deepwater Horizon, a state-of-the-art, dynamically positioned floating semi-submersible drilling platform that costs BP $502,000 a day to run, was close to finishing drilling a series of exploratory wells in 5000 feet of water and was about to be moved. A report obtained from a drilling industry analyst who asked to remain anonymous due to a pending investigation, shows that the rig workers had recently set and cemented a casing and were in the process of displacing the riser (a pipe that encloses the drill string from the platform to the sea bottom) with seawater and setting a surface plug when the well blew out.
The report reads, "the incident appears as if it was either the product of gas migration through the cement sheath as it was setting or that the act of displacing the riser to seawater reduced the hydrostatic head enough that it caused the well to start flowing though cement that was not yet hard. With casing in the ground, these two possible explanations seem by far the most likely, although its impossible at this point not to rule out some other cause or contributing factor such as a blowout preventer or a casing integrity issue."
"Blowouts happen four to five times a years," says Bill Markus, vice president of response at the legendary Texas firm of Boots & Coots, "down from 11 to 15 in 2000." Boots & Coots is not working on the Deepwater incident and Markus cautions that he has no specific knowledge of what happened or if it was even a blowout.
The work BP is doing in the Gulf of Mexico is part of a flurry of drilling in what's known as deep and ultra-deep water—from 5000 to 10,000 feet of water, and up to another 30,000 feet underground—which is riskier and far more complex than drilling in shallow water or on land. The deeper the well, the higher the temperature and pressure of the fluids or gas, and as those fluids rise, they expand ever faster. In what's known as high-pressure, high-temperature drilling, even small gas bubbles become enormous as they travel toward the surface. "That's the inherent danger of drilling deeper," says Markus. "You have small gas influxes all the time, but in ultra deep they become radical."
In addition, the farther offshore, the more complex every piece of the logistical puzzle becomes, especially when an unexpected tragedy strikes. Fires on any drilling rig are rare, but when they happen, especially offshore, they can be very dangerous.
No oil company wants to have a blowout and these companies spend vast sums of money and expertise to ensure that they never happen. But happen they do, and Markus says that while most insurance companies always attribute them to human error, in reality no two are the same. "If this was a blowout," he says, "it's the first deep-water one in the Gulf of Mexico that I can think of. And for that to happen requires the perfect storm of scenarios."