Sedco 706: leak nothing to do with Transocean
The leak, about 160 kilometers (100 miles) off the coast of Brazil's Rio de Janeiro state. was the result of an underestimate of pressure in the offshore oil reservoir that was the target of their drilling and an overestimate of the strength of undersea rock.
As a result, high pressure oil was able to leak into the well bore hole. While the well was immediately shut off, the pressure from the so-called "kick" caused the bore-hole wall to crack and oil to seep through crevices and porous rock to the seafloor and then up into the ocean.
Chevron owns 52 percent of Frade, which is producing about 79,000 barrels of oil and natural gas equivalent a day, and is the fields operator. Petrobras owns 30 percent and a Japanese Group known as Frade Japan owns 18 percent.
The well, which is being abandoned, was drilled by Transocean from their Sedco 706 rig. Buck said the problems at the well "had nothing to do with Transocean."