SEOUL: South Korea’s S-Oil forecast on Friday that second-quarter refining margins will be steady, supported by regular maintenance in the region, then trend upward in tandem with higher demand as the summer season gets underway, according to Reuters. Over the January-March period, the refiner said it operated the crude distillation units at its 669,000-barrel-per-day oil refinery in the southeastern city of Ulsan at 91.9 percent of capacity, compared with 94 percent in October-December. S-Oil, whose main shareholder is Saudi Aramco, plans to shut its No. 1 crude distillation unit sometime this year for maintenance, the company said in an earnings presentation, without specifying the time.