Anita Dodd sold almost a million dollars' worth of beads last year, and she'll probably do better this year. But you won't find her product at the jewelry counter.

Dodd's beads are on the price lists of the world's largest distributors of oil-well drilling fluids, such as Milchem and Magcobar. Made of heattreated glass, each bead measures less than 3/10,000 of an inch in diameter. The beads are mixed with the drilling fluid that is pumped into an oil well, then poured between the pipe and exterior casing, where they act like tiny ball bearings to keep the pipe turning smoothly.

To overcome the neghtmare of stuck pipes, which can shut down an entire rig, drillers have tried as lubricants everything from plastic beads to an oil-based spotting fluid, both of which continue to be used with limited success. One day Dodd, then an oil-field chemicals saleswoman, took a request from one of her customers for glass beads. "He meant plastic, but said glass, and I took him at his word," Dodd says. When she couldn't find the product in any sales catalog, she invented it.

A glass maker produced the first small batch of beads, which Dodd patented, and then tested with a drilling engineer. The glass beads worked effectively, especially on difficult wells, which are drilled at angles. And, unlike other products, the beads stayed round under high pressure and temperatures.

Dodd, 36, formed Dodd International Inc. in Houston in 1976 and is the chief executive and principal shareholder. She splits her time between long-distance conferences with her distributors and "muddy-boot" visits to remote drilling rigs.

Breaking into the male-dominated "oil patch" as a saleswoman was surprisingly easy. "First [the men] were curious," says Dodd, who has a limited college and technical background. "Then they would find something I didn't know and start explaining it to me." Along the way she acquired the necessary "field smarts."

"It's funny," says Dodd. "I was brought up in Louisiana's Cajun country, and I never really expected to be anything but a housewife. Things just happened to me."