Geophysics

Sunlight filters through the stained-glass windows as Francisco Ortigosa wanders around the Torre Girona chapel, his eyes taking in all the details. And what details they are: there are the thick beige stone walls, the Romanesque arches, the ornately carved wooden doors, and the sleek black cabinets housing the massively parallel supercomputer.

Yep, this is no ordinary chapel. Situated on the campus of the Technical University of Catalonia, in Barcelona, Spain, this chapel has been converted into the world’s most beautiful server room. It houses MareNostrum, the third most powerful supercomputer in Europe. The place is still inspiring, but these days visitors like Ortigosa come here for enlightenment not on spiritual matters but rather on the leading edge of high-performance computing.

Ortigosa is the director of geophysics at Repsol YPF, the Spanish oil giant. He heads an ­ambitious—and potentially stunningly ­lucrative—geophysical supercomputing initiative dubbed the Kaleidoscope Project. The goal of the project is to develop an entirely new class of seismic-imaging codes—the computer algorithms that transform raw seismic data into useful, detail-rich images of the Earth, kilometers below its surface. Ortigosa hopes those images will reveal oil and gas reservoirs that current codes can’t uncover.

Kaleidoscope will more fully unleash the power of supercomputers like MareNostrum, which was built by IBM and has 2560 computing nodes and a peak performance of 94.21 ­trillion ­floating-point operations per second (teraflops). Today’s most advanced seismic codes create color-coded three-dimensional maps of the ­subsurface realm by solving a mathematical construct known as the one-way wave equation, which describes seismic waves traveling in just one direction. But Kaleidoscope codes will solve the two-way wave equation, greatly improving the level of detail by taking into account waves propagating in multiple directions.

Repsol, based in Madrid, plans to use the new technology to locate hydrocarbons buried kilometers below the seafloor in the Gulf of Mexico—and below more than 2500 meters of ocean. That’s what oil companies call ultradeep water, and it’s the new frontier in petroleum exploration. Codes based on the one-way wave equation can’t accurately image the thick bodies of salt that typically trap hydrocarbons so far down. Repsol’s ­geophysicists are confident that two-way wave equation codes will overcome this limitation, allowing them to search for oil under 10 kilometers of sediment and hard rock where the salt bodies and underlying oil hide.

”Seismic imaging today uses lots of approximations,” Ortigosa says. ”Our codes will create a closer representation of the actual physics of the Earth. We’re not taking shortcuts.”

To carry out its plan, Repsol recruited two partners: 3DGeo, a seismic software firm headquartered in Santa Clara, Calif., and the Barcelona Supercomputing Center (BSC), which operates MareNostrum. The American geophysicists are developing the codes to solve the two-way wave equation, and the Spanish computer scientists are figuring out how to run the codes efficiently on supercomputers—MareNostrum in the immediate future and later on a BSC system based on the Cell processor, the powerful number-crunching chip developed jointly by IBM, Sony, and Toshiba.

Geophysicists have been chasing the holy grail of the two-way wave equation for years. The problem is that to even think about solving it required more than 10 times the computing power and around 100 times the data storage capacity than was typical of available supercomputers. But more recently, rising processing power and oil prices have conspired to at last put the solution within reach.

And it’s happening not a moment too soon. In the Gulf of Mexico, for example, most of the hydrocarbon reserves in the rela­tively shallow shelf waters have been drained. The easy oil is gone. But in deep waters there’s plenty left: at least 56 billion barrels of oil equivalent—a measure that includes oil and natural gas—which at US $90 a barrel would fetch about $5 trillion and meet the entire U.S. demand for oil and gas for five years. The catch is that finding oil at such depths is extremely challenging and hugely expensive.