Calgary-based TransCanada shut the 590,000 barrel-per-day pipeline, one of Canada’s main crude export routes linking Alberta to U.S. refineries, on Nov. 16 after the leak was detected.
The pipeline was restarted about two weeks later, but the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA) ordered TransCanada to operate at reduced pressure after the 5,000-barrel oil leak in South Dakota.
Energy data provider Genscape said on Thursday the pipeline flow averaged an estimated 524,000 bpd last week.
The reduced flows have contributed to inventory declines at the Cushing, Oklahoma storage hub and pressured Canadian crude differentials, traders said.
PHMSA did not immediately comment on when the line would be allowed to return to full capacity.
(Reporting by Devika Krishna Kumar in New York; Editing by Marguerita Choy)