Deepwater Horizon Cofferdam Hits Snag

The four-story containment box that BP put over the Deepwater Horizon rig had never traveled such depths before. Well, those cold, icy depths caused a problem. Ice-like methane crystals formed in the tank making it impossible to funnel the oil to a nearby tanker. BP is working on a smaller box that may be ready by mid-week. The company is hoping the smaller box will be less likely to encounter icy problems.

Latest Oil Spill Cleanup Projects and Possibilities

BP carries on with finding ways to make the tank work as well as other ways to deal with the leak. But all of them haven't been done in 5,000 feet in dark waters at frigid temperatures.

Another option under review is cutting the riser pipe and then using a larger pipe to drive the leaked oil to the surface onto a ship. However, cutting the pipe will increase the flow. BP is also exploring the "junk shot" in which crews shoot mud and concrete into the failed blowout preventer. Crews -- over 10,000 people involved in the whole process -- continue to drill relief wells. The cost of cleanup has surpassed $350 million.

Aerial and surface operations keep on spraying dispersants and skimming. Helicopters may drop sandbags in five areas in four miles of the coastline to block the spill that has reached beaches in Louisiana.

Alabama officials have installed oil-blocking booms to create a lock system across the four-mile bay's mouth to put up a wall. This busy seaport will have ships entering the first gate where it will be scrubbed and then exit the second gate.

Cause of Explosion

The explosion occurring on April 20 that killed 11 workers may have resulted from a methane gas bubble that burst through a cement seal, which pushed seawater in the riser and then the blowout preventer failing. The methane bubble expanded and picked up speed.

Furthermore, an Associated Press investigation found that blowout preventers have failed at least 14 times in other wells since federal regulators eased up testing requirements. Blowout preventers are cutoff valves that protect the tip of the wells as the last step in the line of defense.

The U.S. Coast Guard and U.S. Minerals Management Service plan to start investigating the cause on May 11. To date, about 3.5 million gallons of oil has spilled. If the pace continues, it could surpass the Exxon Valdez 11-million-gallon spill by June.