Billionaire wildcatter Harold Hamm, a founding father of the U.S. shale boom whose personal fortune has fallen by more than half in the past three months, said U.S. drilling will slow as producers cut back amid falling oil prices.

Declining activity from Texas to North Dakota won’t be as harmful to the industry as some have feared, the chairman and chief executive officer of Continental Resources Inc. said. OPEC’s refusal to curb output last week bodes well for U.S. producers that can outlast countries in the cartel, which depend on higher oil prices.

“Will this industry slow down? Certainly,” Hamm said yesterday in a telephone interview. “Nobody’s going to go out there and drill areas, exploration areas and other areas, at a loss. They’ll pull back and won’t drill it until the price recovers. That’s the way it ought to be.”

Investors have been spooked as oil has declined to a five-year low. The downturn comes after prices above $100 a barrel sparked a boom in output from U.S. shale formations that helped create a glut of supply.

Hamm’s wealth, which is largely tied to the fate of Oklahoma City-based Continental, has fallen by more than $12 billion in three months, according to the Bloomberg Billionaires Index.

Bouncing Back

Hamm, who helped discover the potential of North Dakota’s Bakken formation, predicted a swift recovery in oil prices, which have declined more than 36 percent since June as Saudi Arabia and its allies in the Organization of Petroleum Exporting Countries refused to cut production last week to help re-balance the market.

The company said last month it’s sold nearly all its hedges through 2016, in a bet on a recovery in prices. West Texas Intermediate, the U.S. benchmark, fell below $65 a barrel yesterday before settling up 4.3 percent to $69.

Drillers from Texas to North Dakota are pumping the most in three decades, with many betting they can outlast Venezuela, Iran and other nations that need higher oil prices to fund government budgets.

The price drop has come about more because of “rhetoric” from Saudi Arabia than fundamentals of supply and demand, Hamm said. While prices are low, shale producers have the upper hand, he said.