Chevron Corporation, the second-largest U.S. oil company, announced Wednesday that its board had approved a $15 billion share buyback program over the next three years, the latest in a series of huge repurchases by oil companies. Chevron said its new repurchase program was equal to the three $5 billion buybacks that were completed in 2005, 2006, and 2007. Oil companies have been buying up massive amounts of their own stock on the market to pass the record profits from soaring energy prices back to shareholders. “We believe it is appropriate to continue to return cash to our stockholders through share repurchases,” said Chevron chief executive Dave O'Reilly. “Our continuing strong cash flows have enabled us to fund a significant capital program budgeted at almost $20 billion in 2007, increase dividends to our stockholders, repurchase our shares in the market, and reduce the company's debt.” Chevron's buyback matches the $15 billion program that ConocoPhillips announced in July. Chevron has been buying about $1.1 billion of its shares from the market per quarter, well below industry leader Exxon Mobil's top mark of $9.2 billion in the fourth quarter of 2006. Crude-oil prices reached a record high of $83.90 a barrel last Thursday, fueled by the U.S. interest-rate cuts, the weakening U.S. dollar, and fears of supply disruptions from storms in the Gulf of Mexico.