Oil prices rose on Tuesday amid OPEC-led supply cuts and U.S. sanctions against Iran and Venezuela, although analysts expect surging U.S. output and concerns over economic growth to keep markets in check. U.S. West Texas Intermediate (WTI) crude oil futures were at $52.69 per barrel at 0751 GMT, up 28 cents, or 0.5 percent, from their last close. The ongoing closure of parts of the Keystone pipeline that brings Canadian oil into the United States also helped prop up WTI, traders said. International Brent crude futures were up 38 cents, or 0.6 percent, at $61.89 per barrel. Analysts said markets are tightening amid voluntary production cuts led by the Organization of the Petroleum Exporting Countries (OPEC) and because of U.S. sanctions on Venezuela and Iran. But some said supply-side risks […]