TOKYO, Sept 14 (Reuters) - Oil prices were mixed on Monday with U.S. crude rising as a tropical storm in the Gulf of Mexico forced rigs to shut down, but the gains were kept in check by wider concerns about excess supply and falling demand for fuels.
U.S. West Texas Intermediate (WTI) crude futures CLc1 were up 9 cents, or 0.2%, at $37.42 a barrel by around 0050 GMT. Brent crude LCOc1 was down 3 cents at $39.80 a barrel.
Both contracts ended last week lower, a second consecutive week of declines.
Tropical Storm Sally gained in strength in the Gulf of Mexico west of Florida on Sunday and was poised to become a category 2 hurricane. The storm is disrupting oil production for the second time in less than a month after hurricane Laura swept through the region. oil rises when production is shut but with the coronavirus pandemic getting worse demand concerns are to the fore, while global supplies continue to rise.
"A lacklustre driving season in the U.S. has seen the market reassess its view of U.S. demand," ANZ Research said in a note. Also "with U.S. refiners now shutting down for maintenance, crude demand is likely to remain soft."
The U.S. is the world's biggest oil consumer and producer.
BP Plc BP.L and Equinor ASA EQNR.OL evacuated staff from some offshore platforms on Sunday after similar moves by Chevron Corp (NYSE:CVX) CVX.N and Murphy Oil Corp (NYSE:MUR) MUR.N the day before. Libya, commander Khalifa Haftar committed to ending a months-long blockade of oil facilities, a move that would add more supplies to the market, although it was unclear if oil fields and ports would begin operations.