International crude oil prices are close to undercutting the main U.S. grade for the first time in 18 months, a signal to Societe Generale SA that Saudi Arabia’s strategy of curbing growth in shale production is working. The CHART OF THE DAY shows how West Texas Intermediate, the U.S. oil grade traded in New York, cost $1.28 a barrel less than Brent, the international benchmark, at 9:30 a.m. in London today. A year ago, the American price was $15.49 lower, fortifying the nation’s refineries with cheaper feedstocks and hastening a slump for European processors. The gap is narrowing in part because Saudi Arabia is leading the Organization of Petroleum Exporting Countries in maintaining crude production amid a global surplus. The strategy is to curb output growth from shale formations and higher cost producers. A narrower gap helps make international crudes more attractive to U.S. refiners while a wider one […]