Exxon Mobil Corp. has made one of the largest oil and gas finds in the Gulf of Mexico in a decade, the company announced today. The oil major said it made two oil discoveries and a natural gas discovery in its Keathley Canyon blocks, including an oil discovery in the company’s first exploration well since last year’s moratorium on deep-water drilling. Exxon expects the combined finds to yield more than 700 million barrels of oil equivalent. More than 85 percent would be oil, the company said. Drilling early in 2010 turned up oil and natural gas at the well 250...