Crude oil prices increased slightly as Hurricane Delta forced nearly 29% of offshore oil production to shut down in the Gulf of Mexico.
International benchmark Brent crude was trading at $42.15 per barrel at 0604 GMT for a 0.38% increase after closing Wednesday at $41.99 a barrel.
American benchmark West Texas Intermediate (WTI) was at $40.05 a barrel at the same time for a 0.25% drop after ending the previous session at $39.95 per barrel.
Oil prices saw a limited rise as Hurricane Delta, which strengthened to Category 2, is expected to reach the northern Gulf Coast on Friday with a life-threatening storm surge, according to the US National Hurricane Center.
The US Bureau of Safety and Environmental Enforcement (BSEE) said approximately 29% of the offshore oil production in the Gulf of Mexico is shut-in.
Evacuations from a total of 183 offshore oil facilities have been made over expectations that the hurricane will intensify and rise to category 3, curbing approximately 1.5 million barrels of daily oil production.
Prices were also negatively affected after data released by the country's Energy Information Administration (EIA) showed that commercial crude oil inventories in the US rose more than forecast by 500,000 barrels last week relative to the market expectation of a 400,000 million-barrel rise.
In its Short-Term Energy Outlook (STEO) for October, the EIA said high inventory levels and surplus crude oil production capacity would limit upward pressure on oil prices.
The administration also said "reduced economic activity related to the COVID-19 pandemic has caused changes in energy demand and supply patterns in 2020 and will continue to affect these patterns in the future."
Because Libya is excluded from the current production agreement among members of the Organization of the Petroleum Exporting Countries and partner countries (OPEC+), the EIA said an increase in crude oil production from the country could significantly affect crude oil supply and inventories in the coming months.
By Sibel Morrow