The Age of Extreme Offshore Oil Is Just Beginning

 

The oil rig FPSO BW Cidade de São Vicente operating thte Tupi Extended Wall Test

Petrobras News Agency

Marcos Bueno de Moraes still recalls those tense days of drilling. Geophysicists at his firm, the Brazilian oil company Petrobras, had used a novel 3-D seismic technology to probe for oil trapped underneath the seafloor, 180 miles off the coast of southeastern Brazil. It was the mid-2000s, oil prices were just beginning to recover after dragging bottom for more than a decade, and cost cutting was still gospel in the petroleum industry. But with preliminary soundings pointing to a massive cache of crude, the corporate brass overruled the bean counters and took their biggest gamble yet: prospecting four and a half miles beneath the surface of the Atlantic.
From his desk in the company’s concrete-block office tower in downtown Rio de Janeiro, Bueno, an exploration geophysicist, was tasked with interpreting seismic data streaming in from a battleship-gray exploration vessel moored in the open seas, more than an hour’s helicopter flight away. There, discovery crews working day and night had lowered a drill rig through 7,200 feet of water and were trying to break through another one, two, maybe three miles of sand, rock, and a massive crust of prehistoric rock salt to what might—or might not—be a major deposit of “pre-salt” oil below.
Although the potential payoff was huge, the risks were enormous too. In the wake of the BP blowout in the Gulf of Mexico, we now know just how enormous, but even then the perils of going after oil in ultradeep water were no secret to prospectors. Water pressure at those depths is more than 200 times that of the atmosphere at the surface, and no one knew what all the heat, gas, and salt below the seafloor might do to the drilling equipment. “If the pressure was too great and the right precautions not taken, the well could have blown and even set the drill platform on fire,” Bueno recalls. After more than a year of drilling, they had hit nothing. “I remember it was on a Friday that we had to decide: Do we scrap the whole experiment or keep going?