WTI oil prices are lagging Brent crude oil prices, once again, as the focus shifts to US refinery maintenance and a looming demand slowdown. Citgo’s Corpus Christi unit was the latest to announce a shutdown for retooling. The strong refinery run rate, during the second-half of last year, supported WTI prices as has the various pipeline rationalizations. The winter weather remains supportive, as temperatures in the Northeast will remain upward…