Crude-oil futures were choppy in Asian trade Wednesday ahead of this week’s numbers on U.S. oil stockpiles and as investors positioned themselves amid volatile currency markets.

On the New York Mercantile Exchange, light, sweet crude futures for delivery in May CLK5, -0.84%  traded at $ 47.37 a barrel, down $ 0.14 in the Globex electronic session. May Brent crude LCOK5, -0.38%  on London’s ICE Futures exchange fell $ 0.03 to $ 55.08 a barrel.

Oil prices had diverged overnight with Brent crude losing 1.45% in the last trading session. The Brent-WTI spread is at $ 7.72 a barrel.

Late Tuesday, the American Petroleum Institute, an industry group, said its data for last week showed a 4.8-million-barrel gain in crude-oil supplies.

The U.S. Energy Information Administration will publish its weekly oil inventory data today, and analysts expect another increase of 5.6 million barrels.

“Inventories remain crucial in judging the oversupply issue, even more crucial when we take the stand that U.S. [oil] production should be cut. We should be seeing the inventories ease off with some return to refinery utilization rates,” analyst Daniel Ang at Phillip Futures said in a note.

WSJ market wrap: March 24, 2015

U.S. stocks drifted lower Tuesday afternoon in quiet trading as the most recent push toward record highs ran out of steam. Morgan Stanley CFO Ruth Porat is leaving for Google in the same role.

The greenback has eased in recent days, helping to support oil prices to some extent. A cheaper U.S. dollar helps boost oil demand as oil is a dollar-denominated commodity. It also makes it cheaper as an asset class for portfolio investors.

Read: Dollar stays weak as investors look for fresh clues on direction

There is potential for a significant downward correction in the U.S. dollar that could attract more investment into crude oil, as portfolio managers move money away from currency investments, analyst Tim Evans at Citi Futures said.

However, any upward oil price movement will not be in line with oil market fundamentals where an oversupply of around 1.5 million barrels a day is building up for the first half of this year, he said.

This glut could be exacerbated if Arab Gulf producers like Saudi Arabia, Iran and Iraq keep boosting production. Oil market observers are closely watching developments in the U.S.-Iran nuclear talks that will have implications for oil supply.

Nymex reformulated gasoline blendstock for April RBJ5, -0.24%  — the benchmark gasoline contract—was flat at $ 1.8020 a gallon.