LONDON— Shell Oil Thursday reported a 31% decline in third-quarter profit, largely because of weak refining margins and increased exploration-and-production expenses. Shell posted profits on a “current cost of supplies” basis—a figure that factors out the impact of inventories, making it equivalent to the net profit reported by U.S. oil companies—of $4.25 billion, down from $6.15 billion in the same period last year. Shell reported revenue of $116.51 billion, up from $112.12 billion a year earlier. “We are facing […]