Saudi Arabia’s Midad Energy has emerged as one of the leading contenders to buy Russian oil major Lukoil’s international assets, a deal that could reshape ownership of roughly $22 billion worth of oilfields, refineries, and fuel stations as U.S. sanctions force Moscow-linked firms to unwind overseas holdings, according to people familiar with the matter. Lukoil is seeking to sell its foreign operations after sweeping U.S. sanctions imposed in October sharply restricted its ability to operate and finance assets outside Russia. The portfolio…