Chevron and Exxon have spent lavishly to boost their oil and gas output, but production has been dropping and profits have been muted. Chevron Corp. said its first-quarter global oil and gas production is expected to drop from the year-ago quarter, as poor weather led to downtime in the U.S., Canada and other regions. Chevron, the second-largest U.S. oil company in market value after , forecast first-quarter earnings to be lower than the fourth quarter, hurt by foreign-currency fluctuations and asset impairments and other charges. The company said global oil-equivalent production in January and February totaled 2.58 million barrels a day, down 2.5% from the year-ago period. Throughout the oil giant’s interim report, Chevron compared the first two months of the first quarter with the entire quarter of the year-earlier period and all of the fourth quarter […]