Singapore refining margins for Dubai crude surged 240% since mid-October, hitting $6.62 on Nov. 29. Despite higher Aramco OSPs, Saudi crude is now more competitive in Asia than Russias Urals. https://t.co/H0i4eRjKuD https://t.co/DhmRe47d7K https://t.co/o4gfq36XB7.