FWIW, here's a much more technical article about the techniques used in the creation of the Deepwater well. Lots of inside-baseball comments from petroleum engineers, actually quite interesting.

The BP well "is not a design we would use," said one veteran deep-water engineer who would comment only if not identified because of his high-profile company's prohibition on speaking publicly about the April 20 explosion aboard the Deepwater Horizon or the oil spill that started when the drilling rig sank two days later.

He estimated that the liner design, used nearly all the time by his company, is more reliable and safer than a casing design by a factor of "tenfold."

But that engineer and several others said that had BP used a liner and casing, it would have taken nearly a week longer for the company to finish the well — with rig costs running at $533,000 a day and additional personnel and equipment costs that might have run the tab up to $1 million daily.