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 obstacles will discourage development unless crude prices stay high, said Tina Vital, an analyst at Standard & Poor's in New York. U.S. oil futures, which reached a record at $119.93 a barrel in after-hours electronic trading yesterday, have jumped 81 percent in the past year.
Engineers will have to overcome temperatures that range from near freezing above the ocean floor to temperatures that can melt bismuth, used for transporting uranium rods and for shotgun shells. Layers of salt will also increase the challenge because the crystals absorb seismic waves used to pinpoint oil deposits.
``The seismic issue is important because if you don't identify the location of the oil properly, you're going to waste a lot of money when you drill the hole in the wrong spot,'' said Vital, a former Exxon engineer.
Brazil pumped 2.13 million barrels of oil a day in the last three months of 2007, more than OPEC members Angola, Libya and Algeria.
Tupi, 155 miles (250 kilometers) off Brazil's coast, may begin production by 2012, according to consulting firm Strategic Forecasting in Austin, Texas. The field may have 8 billion barrels of recoverable oil.
No start date has been set for Carioca, which Petroleo Brasileiro said will take at least three months to evaluate. A Brazilian regulator said this month the reservoir may have 33 billion barrels.
If confirmed by further drilling, the reserves will be triple the size of Alaska's Prudhoe Bay, the largest U.S. field.
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.
Saturday, May 3, 2008
Technological Barriers To Carioca Field
Brazil Oil Trapped by 500-Degree Heat, Salt Barrier