U.S. cash crude differentials ended the week mixed, dealers said on Friday, with grades in the north drawing support from reduced supply after a cold spell hit production in some parts of the country.

North Dakota’s oil output could take about a month to recover after a severe freeze cut production by more than half this week, state officials said.

Crude output in the third-largest oil producing state was estimated to be down 350,000 barrels per day (bpd) to 400,000 bpd, or about 30%, on Friday, according to the North Dakota Pipeline Authority.

Since the disruptions, spot prices for Bakken crude in Clearbrook, Minnesota, have strengthened to a $2.96 a barrel premium to U.S. crude futures CLc1, versus a $1.99 a barrel premium last month.

Meanwhile, West Texas Intermediate crudeat East Houston WTC-MEH, also known as MEH, traded at a five-week low, dealers said, at a $1.35 premium to U.S. crude futures.

This week’s winter storm also affected operations at refineries in Texas, including TotalEnergies’ 238,000-bpd Port Arthur plant and Pemex’ 312,500-bpd Deer Park refinery, sources said.

U.S. oil refiners are expected to have 1.5 million bpd of capacity offline for the week ending Jan. 19, decreasing available refining capacity by 992,000 bpd, research company IIR Energy said.

Offline capacity is expected to rise to 1.60 million bpd in the week ending Jan. 26 and then fall to 1.56 million bpd in the subsequent week, IIR added.

The number of U.S. oil rigs fell by two to 497 this week, their lowest since mid November, energy services firm Baker Hughes BKR.O said.

Light Louisiana Sweet WTC-LLS for February delivery fell 30 cents at a midpoint of a $2.50 premium and was seen bid and offered between a $2.40 and $2.60 a barrel premium to U.S. crude futures.

Mars Sour WTC-MRS fell 25 cents at a midpoint of a 50-cent premium and was seen bid and offered between a 40-cent and 60-cent a barrel premium to U.S. crude futures.

WTI Midland WTC-WTM gained 20 cents at a midpoint of a $1.85 premium and was seen bid and offered between a $1.75 and $1.95 a barrel premium to U.S. crude futures.

West Texas Sour WTC-WTS gained 25 cents at a midpoint of a 90-cent premium and was seen bid and offered between a 80-cent and $1.00 a barrel premium to U.S. crude futures.

WTI at East Houston WTC-MEH, also known as MEH, traded between a $1.25 and $1.45 a barrel premium to U.S. crude futures.

ICE Brent March futures LCOc1 fell 54 cents to settle at $78.56 a barrel.

WTI February crude CLc1 futures fell 67 cents to settle at $73.41 a barrel.

The Brent/WTI spread WTCLc1-LCOc1 widened last to minus $5.25 at 15:21 CST, after hitting a high of minus $5.01 and a low of minus $5.35.
Source: Reuters (Reporting by Georgina McCartney, Editing by Marguerita Choy)