The Uncharted Depths  

Bloomberg has an interesting report on some of the technical challenges facing Petrobras as it tries to develop new fields offshore Brazil.

Brazil's plan to become one of the world's biggest oil exporters hinges on exploiting crude 6 miles below the ocean surface in deposits so hot they can melt the metal used to carry uranium to nuclear plants.

Tapping what may be the biggest oil finds in the Western Hemisphere in three decades will require equipment that can withstand 18,000 pounds per square inch of pressure, enough to crush a pickup truck, pipes that can carry oil at temperatures above 500 degrees Fahrenheit (260 Celsius) and drill bits that can penetrate layers of salt more than one mile thick.

Petroleo Brasileiro SA, the state-controlled oil company, is betting on the Tupi and Carioca fields to become one of the world's seven biggest crude exporters. Until the tools needed to exploit the reservoirs are invented, the crude will remain locked under the sea, said Matt Cline, a U.S. Energy Department economist.

``This is a very, very technically challenging environment where no one's ever done this,'' Cline, who tracks the Latin American oil industry, said in a telephone interview from Washington. ``These discoveries are in very deep water, and once you get to the seabed they are very deep under the floor, with a layer of salt that is definitely a difficult barrier.''

Brazil's oil will be harder to develop than the Gulf of Mexico, where the deepest wells are now in production, Cline said. Exxon Mobil Corp. and Chevron Corp., the two biggest U.S. oil companies, saw diamond-crusted drill bits disintegrate and steel pipes crumple when they attempted to tap deposits beneath the Gulf's seafloor two years ago.

Pumping oil from the Brazilian finds, parts of which are 32,000 feet (10,000 meters) below the ocean's surface, will require boring almost twice as far down as the world's deepest producing offshore well. ...

The ocean-depth record for production was set last year by Anadarko Petroleum Corp. The company is extracting natural gas from beneath 8,960 feet of water in the Gulf of Mexico, where pressure measures 3,069 pounds per square inch, squeezing joints and tearing at seals.

``What we do at that water depth in the ocean is similar to NASA's space program, but they get to do it without any pressure trying to attack them,'' Kevin Renfro, production engineering manager at Woodlands, Texas-based Anadarko, said in a November interview.

Petrobras hasn't said how much it spent to sink wells at Tupi and Carioca. Similar drilling by Exxon and Chevron Corp. in the Gulf of Mexico cost $180 million to $200 million for each well.

``A big find might not be a good find if it costs so much to develop that it's not commercially viable,'' S&P's Vital said. ``We don't have any idea at all yet of all the costs that are going to be involved. Those costs are going to set the floor for oil prices.''