Exxon Mobil, Shell and BP all posted disappointing earnings this week. Chevron is expected to post a profit decline Friday. All of them face the same problem: The cost to get newfound oil from remote locations and tightly packed rock is high and rising. And it takes years and billions of dollars to get big new production projects up and running. The higher extraction costs could translate to higher oil and gasoline prices for consumers. Strong production growth at an oil company can offset higher operating costs, “but when production is flat or declining it’s a big hit,” says Brian...