Science may be on the verge of launching a new oil rush.
For 30 years, petroleum geologists have known that ancient meteorite craters trapped oil reserves. Now a Texas researcher says many more craters exist than were suspected and that discovering them by high-tech means such as satellite imagery should unearth many new oil, gas and mineral deposits.Dave B. Buthman of the company Unocal, based in Sugar Land, Texas, spoke Monday afternoon during the annual meeting of the American Association of Petroleum Geologists in the Salt Palace. The group is meeting through Wednesday. It claims to be the world's largest geological science organization with more than 31,000 members in 110 countries.
According to the association's communications director, Larry M. Nation, about 6,000 geologists and other experts are attending. The Salt Palace Exhibition Hall is packed with displays, and on the building's upper floor the U.S. Postal Service has been selling special commemorative envelopes to mark the occasion.
According to Buthman, weathered impact craters from the strikes of meteorites or asteroids are known to produce oil and gas at such far-flung sites as Red Wing Creek Field, N.D.; Viewfield Field in Saskatchewan, Canada; the Avak Structure and Barrow Gas Field, Alaska; and fields in Michigan, Oklahoma and India.
Production from these "astroblemes," the technical name for the craters, is estimated at more than 2.3 billion barrels of oil, he said.
But that is only the first drips of a potential gusher, according to Buthman. Eventually, production from other known craters, about two dozen altogether, could amount to 43 billion barrels, he said.
The famous Chicxulub crater in Mexico's Yucatan Peninsula and an adjacent part of the Gulf of Mexico is thought to harbor 23 billion barrels. Chicxulub, discovered within the past 20 years, is thought to be the remains of the crater formed by the impact of the asteroid that killed off the dinosaurs 65 million years ago.
And the potential bonanza doesn't stop there, he said. Buthman believes Earth is peppered with thousands of craters that have been obliterated over time through erosion by wind, waves and the deposit of sediments. Many of them may hold reservoirs of oil, gas or minerals, he said.
Next year, a suspected crater in Oklahoma will be explored to see if oil fields turn up where Buthman thinks they may be: in the central peak of the crater and within the higher rims of the circular sides.
Craters form basins that eventually fill with oil-impregnated sediments. The oil tends to rise through geological features, migrating upward in the central peak and the crater rims, where it may remain trapped.
In some regions, gold, diamonds and other minerals may be associated with prehistoric craters. "The impact fractures the Earth and allows super-heated waters to deliver hydro-thermal ores to the surface," he said. The minerals also become trapped in the crater's basin, resulting in ore deposits.
Diamonds can be formed by the force of the impact on carbon.
Judging by heavily cratered bodies like the moon, Mars and Mercury, this planet also was struck innumerable times by meteorites, he said. Their outer traces have been obliterated, but the structures may lurk beneath ocean sediments or deep underground.
"I think there's 30,000 to 50,000 that are significant size," he said. For a typical region of ten miles by ten miles, "you should expect at least one crater."
Geologists only have to discover the structures through remote sensing, magnetometers, seismic surveys, drilling and computer mapping. Then they can calculate where oil reserves may have migrated or where minerals could be mined.
Today only about 400 impact structures are known on Earth, but they "will one day number in the thousands," Buthman predicted.
How much oil can be discovered that way? That's anybody's guess, he said.