Oil prices declined despite a drop in U.S. oil inventories. The U.S. Energy Information Administration (EIA) released its crude oil inventories data on Wednesday. U.S. crude inventories fell by 1.9 million barrels to 454.0 million in the week to September 18.

Analysts had expected U.S. crude oil inventories to decline by 1.5 million barrels.

Gasoline inventories increased by 1.4 million barrels, according to the EIA.

Crude stocks at the Cushing, Oklahoma, declined by 462,000 barrels.

U.S. crude oil imports fell by 13,000 barrels per day.

Refineries in the U.S. were running at 90.9% of capacity, up from 93.1% the previous week.

Concerns over the slowdown in the Chinese economy weighed on oil prices. The Chinese preliminary Markit/Caixin manufacturing Purchasing Managers' Index (PMI) decreased to 47.0 in September from 47.3 in August, missing expectations for a rise to 47.5, and hitting a 78-month low.

The output index fell to 45.7 in September from 46.4 in August, reaching a 78-month low. New orders, new export orders, employment, output prices and input prices also declined.

WTI crude oil for October delivery fell to $46.18 a barrel on the New York Mercantile Exchange.

Brent crude oil for October declined to $48.78 a barrel on ICE Futures Europe.