Whenever a hurricane is moving through the Gulf of Mexico, there’s a worry that may not be foremost on everyone’s minds. It’s about the oil platforms.
According to The Atlantic magazine, 17 percent of U.S. oil production relies on offshore drilling in the Gulf. Under normal conditions, it’s a benign environment. The water never freezes there, and temperatures remain moderate.
Most of the drill rigs and platforms are clustered in an arc spanning the shallow waters from Texas to Florida. The depths there typically range between 100 and 500 feet, which makes it possible for a platform to be sitting solidly on the seafloor.
Things get more difficult at greater depths. About 200 miles south of New Orleans, the continental shelf drops rapidly to 10,000 feet depth.
Deep-water platforms are designed to float. They are not held in place by anchors. Piles embedded in the ocean bottom hold steel tethers reaching upward to the floating structure. The heights of such installations can be monstrous.
Magnolia Platform in the Gulf, for example, has a “tension leg platform” design with a total height of almost 4,700 feet. In September 2016, it was outranked by Stones, a Shell Co. operation, which reaches down an incredible 9,500 feet.
Just like icebergs, oil platforms show only a tiny amount of their height above the ocean surface. They look like they are standing on water, but in reality their bodies extend far below the waves.
The difficulty of offshore drilling becomes understandable by visualizing it in the horizontal.
Magnolia’s wells extend some 17,000 feet into the bedrock, or 3.25 miles. Imagine a drill bit a few inches in diameter, laid on the ground at the square in Gainesville, running the entire length of Spring Street, turning onto Jesse Jewell at Northeast Georgia Medical Center and following that highway all the way to the Rabbittown Café.
At the cutting edge of technology, accidents happen. The latest spill occurred on Oct. 14, releasing roughly 9,000 barrels of crude oil into the Gulf 40 miles from the Louisiana coast. The Deepwater Horizon explosion spilled 3 million barrels in 2010.
It’s a saving grace that marine bacteria use crude oil as food, and can consume it given enough time. The big problem with crude oil spills is pollution of the shorelines and the impact it has on marine mammals and birds.
Rudi Kiefer, Ph.D., is a professor of physical science and director of sustainability at Brenau University. His column appears Sundays and at gainesvilletimes.com.