On Wed, 16 Jun 2010 18:18:45 -0500, Jim wrote:


4. Deep offshore drilling can be made safe with correct procedures. One
way is to require an initial 100' cemented caisson with double failsafe
shutoffs instead of a single blowout preventer on the seabed. Drilling
then proceeds through the caisson. Oh, that adds $20-40 million to the
well cost? Big deal.

Standard procedure when spudding in a new hole. IIRC, you drill several
hundred feet, set casing, and cement it in. That "single blowout
preventer" is a bit of a misnomer. The BOP has three rams, a shear, an
annular, and another ram I forget the name of. BOPs, properly sized and
maintained, work. They are not meant for abandonment of the hole, but in
a pinch ... There real purpose is be able to seal the whole, while
weighting up the mud, circulating on choke, and regaining control of the
well.

I think you will find when the investigation is complete, BP made some
decisions based on economics, that were rather short sighted. One, they
continued operation with a damaged annular ram. Two, switching the mud
for seawater, was, I believe, the direct cause. 5,000 feet of properly
weighted mud may have kept the gas incursion from ever happening. Using
seawater was reckless.