Tuesday, April 27, 2010

After an explosion aboard an oil rig four days ago, an oil spill caused by the sinking of the rig has expanded to cover an area of around 600 square miles (1550 square kilometers), and efforts to shut off the leak have thus far been unsuccessful.

Officials have begun to use robotic submersible vehicles to stop the leak. The efforts began yesterday, although it could be as late as tomorrow before they are completed. The vehicles will attempt to engage a device called a blowout preventer, which can seal the well shut to prevent sudden releases of pressure within the well, like the one that may have caused the rig to explode. According to BP, the company that operated the well, the attempt was the first of its kind in the world.

The leaks are on a pipe from the ocean floor called a riser. They are currently estimated to be releasing around 42,000 gallons of oil a day into the Gulf of Mexico, and the oil slick on the surface of the ocean is estimated to cover an area about 48 by 39 miles at its widest points. Officials say oil is not expected to reach land until at least Thursday, and would remain at least 30 miles from land through Tuesday. The impact of the spill on wildlife is currently unknown; there have been no reports of animal casualties, though whales were seen in the vicinity of the spill yesterday.

According to officials, there are two other possible ways to contain the oil spill if the attempt to seal the well is unsuccessful. One option would be to install a large dome over the leak and send the collected oil to the surface, where it would be collected by ships. This has been done before, although only in shallow water. The second option is to drill an entirely new well that would intersect the original, although this could take months to complete.