How the leak happened…
On April 20, the Deepwater Horizon, a drilling rig 50 miles off the coast of Louisiana in the Gulf of Mexico, exploded into flames. Two days later the rig sank, causing the 5,000 foot pipe that connected the wellhead to the drilling platform to bend. On April 24, robotic devices discovered two leaks in the bent pipe, nearly a mile below the ocean surface.
Methods That Have Been Tried to Stop the Leaking Oil
May 31 -> Another attempt to cap the well. This is still in progress.
May 26 -> Top Kill and Junk Shot. Try to stop the oil by pumping heavy drilling liquids and injecting objects like golf balls to clog the blowout preventer. This method was abandoned after several attempted.
May 16 -> Attaching a tube. Used to siphoned off a portion of the leak to a drill ship on the surface. Just a fraction of what is leaking out is siphoned off. This has been stopped when BP was trying other methods of stopping the leak.
May 7 -> Lowering a containment dome. A 4 story containment dome was build in an attempt to contain and direct the oil to a tanker on the surface. The main opening was clogged by an icy mix of gas and water.
May 2 -> Drilling relief wells. 2 news drilling points have started, and are now (May 31) half way to the target. BP will use this new wells to try to stop the leak. This might take another month.
April 30 -> Chemical dispersant. BP used a more toxic chemical dispersant until E.P.A. directed them to change. The full environment impact is unknown, but oil on the surface will be less visible.
April 25 -> Repairing the blowout preventer. But the blowout preventer failed to activate
With this kind of environmental impact, I believe BP should stop trying to use ideas which will still enable them to have access to the oil and try something more drastic to stop the leak. That’s my take.