Officials used “dispersants” to break up the oil. But some experts think that those chemicals caused much of the oil to remain below the water’s surface, out of reach of standard cleanup techniques. The first attempt to place a “dome” over the well failed because of a well-known problem called hydrate crystals. The government and BP repeatedly under-estimated the oil’s flow, and BP was not ready to capture all of the oil being siphoned up from the well.

In all, it appears that the mistakes have made it harder to fight what President Obama has called a “war” on the oil…

“I would give them a C-plus or B-minus, especially at the beginning. I think it’s getting better now. I think they fell into the trap of following standard steps — the usual procedure you would follow to deal with a situation like this — and the situation was not quite usual,” said Tadeusz Patzek, a professor of petroleum engineering at the University of Texas. “They used up precious time doing things that were not successful.”