In Chevron’s 50- story complex in town Houston, geophysicists are smelling out the coming generation of underwater canvas wells. To do so they are pushing the borders of imaging technology to peer beneath country miles of water, gemstone, and swab layers thousands of bases thick– each in the expedients of chancing billions of barrels of canvas trapped below.
Chevron has 100 prospective drilling spots in the Gulf of Mexico, but its loftiest expedients for a resumption of underwater drilling lay in an area called the Lower Tertiary Wilcox trend, near where the international shelf drops off into deep water. It may be home to 12 billion barrels of the canvas, says James Cearley, Chevron’s disquisition director. This isn’t fluently penetrating canvas, however.” Underwater wells bring$ 100 million each to drill, so Chevron invests in lots of seismic data to alleviate the threat of a dry hole,” says Cearley.
In Houston Chevron’s geologists literally sit on top of 8 petabytes of seismic data –enough to fill DVDs– housed in two bottoms of computer waiters. Each day they collect roughly 5 terabytes of new data. The square country miles of 3-D definitions the geologists have sutured together constitute one of the most comprehensive models of the geology of the Gulf of Mexico.
Seismology for canvas disquisition differs from earthquake seismology, which measures naturally generated seismic swells. To hunt for canvas, specialized seismic companies shoot blaring sonic thunderclaps down into the gemstone. Use detectors to gather the reflected energy; Chevron also has its computers parse out what lies beneath. Each material has a unique”seismic haste,” which helps determine the difference between gemstone and canvas. Imaging ways are so good that geologists can compare standing inside a gemstone conformation to look for the spots most likely to hold the canvas.
Imaging through gemstone is one thing. But seismic data get climbed when it bounces out layers of swab deep under the seabed. To begin gaping through the swab, Chevron in the early 1990s stationed a$ 1 million Cray supercomputer to reuse gulf seismic data in three confines. Inspired, the company began madly leasing underwater disquisition blocks from the theU.S. Government. There, hiding under a subcaste of swabs as thick as bases, Chevron planted the Tahiti field. Which now produces barrels per day from budgets bases deep.
This time Chevron retired its last supercomputer and replaced it with$ of gear on every desktop. What would have taken three months to render on a Cray in 1993 now takes two hours or lower on a PC, says Barney Issen.
Chevron’s elderly geophysicist is in charge of interpreting seismic data. To crunch heavy loads, Chevron networks its computers into Linux- grounded clusters with hundreds of processors operating in parallel. They use high-speed plates cards to run a customized picture platform called God, erected by software maker Paradigm.
These days a lot of Chevron’s combined brain. Computer power is tuned to peer into the gulf’s promising Lower Tertiary Wilcox trend. For decades geologists have discovered bountiful canvas and gas onshore in the Wilcox zone. In the deep water, large swaths of Wilcox deposition drooped over the side of the international shelf. Were swallowed by a subcaste of swabs that dates back to when the American mainlands pulled down from Europe and Africa. In 2005, Chevron discovered canvas in the subsalt Jack 2 well. The coastal Wilcox surfaced as a giant new resource. Chevron plans to invest$7.5 billion to develop Jack.
“When I started, geologists were considered heretics for featuring that there could be swab tents with force- quality gemstone beneath them,” says Issen, 54. Now they understand that as deposition builds up on top of the swab, it pushes the swab out of the way. Like a downside-down lava beacon, in time the deposition sinks under the swab.
Think of the swab subcaste as one of those glass blocks used to make restroom walls. It lets light and color through, but you can not make out any detail. Still, if you can figure out the angles ( geomorphology) on the front and reverse of the glass. You can write computer algorithms to correct them. With the right algorithms backed by enough computing power. The swab subcaste can be converted from a shelter into a lens. Issen shows a 3-D protuberance of a prospective well called Buckskin.
A grandiloquent blob of aged deposition recessions underneath the swab subcaste. A” bump” in the gemstone is a reflective sign that canvas is trapped beneath.”You do not get to see that it’s a bump until you’ve sorted out all this stuff (the swab) above it,” explains Issa. Last time Chevron blazoned that test wells drilled bases deep into Buckskin plant canvas- bearing beach 300 bases thick.
Seeing through swab hasn’t yet been perfected.” Occasionally what we allowed we were looking at was not there at each,” says Cearley. Indeed so Chevron is perfecting its emotional 3-D seismic model of the gulf all the time. The rearmost development allows geophysicists to tweak algorithms on the cover– in effect. Adding a little further swab then or further sandstone there to see if it helps to smooth out the image.
Chevron is working with public labs like Lawrence Livermore, applying advances made in nuclear munitions simulation to the seismic pictures. Seismic specialists like CGGVeritas and Schlumberger’s WesternGeco are coming up with new ways to bounce sound swells off jewels. Says Chevron’s geosciences director Mark Koelmel, “We are going to have to come up with better ways to parse the data. Because we are going to have a lot of further data.”
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