Good to the Last Drop

By Wendy Williams

Last year a Canadian company found as much as a trillion cubic feet of natural gas in a California field long considered past its prime. In Texas's nearly defunct Giddings oil field, reentry wells have yielded an unexpected bonanza of hundreds of thousands of barrels of oil and hundreds of millions of cubic feet of natural gas. Off Louisiana, in the Gulf of Mexico, oil and gas reserves previously hidden by layers of salt are yielding high profits. In Bakersfield, California, an abandoned oil field "has produced more than a million barrels of oil once thought unrecoverable," according to a press release from the U.S. Department of Energy (DOE).

In recent years the oil and gas industry has experienced a massive technological revolution. In public, spokespeople claim that these improvements allow environmentally sensitive oil exploration, which justifies their use in places like the Arctic National Wildlife Refuge. However, they're less likely to point out that the innovations have also vastly increased the amounts of oil retrieved from already opened fields.

While this is true of natural gas, it's particularly true of oil. About 10 percent of all oil reserves ever found in the United States have been found in the past decade, and of those, about 90 percent are in old fields, according to the DOE. "There's a phenomenal reserve growth going on now," says William L. Fisher, an internationally respected geologist at the University of Texas at Austin. "We're going back into old fields and finding that they were more complicated than was previously thought. The saying is now: 'Oil is where you already found it.'"

The key is computerized underground imaging technology, which allows geologists to see the earth's interior more accurately. Think of it this way: Computer visualization is to the old seismology technology as an MRI is to the century-old X-ray technology. Today's oil-company geologists are a bit like laser surgeons, using computers to operate their underground drills in global oil fields from the comfort of their Texas offices. Watching the drill bit on the computer screen, the geologist can instruct an operator to shift one way or the other, perhaps by only a few inches, and hit oil that might otherwise have been missed.

The rewards can be high. Of the Bakersfield breakthrough, the DOE press release says: "In the last five years, the million barrels of 'new' oil that has flowed from the field is more than half as much oil as the property produced in all of its first 80 years of operation. Project sponsors predict that the advanced technologies ultimately will result in more than 4 million barrels of oil being produced--all from a 40-acre property once thought to be dead."

Many expect the benefits to last well into the 21st century. The Texas-based Newfield Exploration Company buys old oil and natural gas fields from large corporations and applies the new exploration technologies to locate leftover oil and gas. There are enough of these abandoned fields, says company spokesperson Stephen Campbell, that half of Newfield's oil and natural gas reserves are in old fields.

Nevertheless, the urge to discover a major new field continues unabated, even though the amount of oil the United States will need in the future is a matter of considerable debate. Harvard energy expert John P. Holdren published an essay entitled "Searching for a National Energy Policy" in the spring 2001 Issues in Science and Technology. He wrote, "For most of the last 30 years, oil's share of U.S. energy supply slowly declined . . . falling from 43.5 percent in 1970 to 38.8 percent in 2000." Ultimately, he concluded, "the answers will be found in improved technologies . . . not in the Arctic National Wildlife Refuge."