Benchmark oil for July delivery was down 40 cents to $93.85 per barrel at midday Bangkok time in electronic trading on the New York Mercantile Exchange.
The contract fell 3 cents to close at $94.25 a barrel in New York on Thursday. The price sank as low as $92.21 in the morning after weak manufacturing data from China raised questions about the strength of oil demand in the world's No. 2 economy.
The prices of West Texas Intermediate and Brent continue to shift downward "as economic data continues to point to reduced demand against a backdrop of high inventories," said Michael Hewson of CMC Markets.
The American Petroleum Institute had said in a statement Wednesday that U.S. crude oil stocks for April ended at 388.9 million barrels, the highest inventory level for the month since 1981.
Traders were awaiting the release by the U.S. Commerce Department of durable goods orders for April for the latest clues on the health of the U.S. economic recovery.
Brent crude, a benchmark for many international oil varieties, fell 14 cents to $102.30 a barrel on the ICE Futures exchange in London.
In other energy futures trading on Nymex:
— Wholesale gasoline fell 0.2 cent to $2.816 a gallon.
— Heating oil lost 0.7 cent to $2.85 a gallon.
— Natural gas rose 1.9 cents to $4.28 per 1,000 cubic feet.