Crude prices fell to their lowest in seven months as global markets appeared to give up hope that OPEC's efforts to drain the worldwide oil glut will succeed any time soon.

Oil dove below $45 a barrel in New York on Wednesday after the U.S. Energy Department reported another sizable increase in petroleum stockpiles, led by a jump in gasoline inventories. The gains stunned traders who expected to see inventories decline as they usually do as U.S. motorists take to the roads during the peak summer driving season, which begins Memorial Day weekend.

"For this time of year, we've never been higher," Kyle Cooper, director of commodities research at IAF Advisors in Houston, said of the petroleum stockpiles. "The idea that OPEC could lower inventories isn't coming to fruition here in the U.S."

Crude prices fell nearly 4 percent to settle at $44.73 a barrel, breaking out of a stable trading range between $45 and $55 a barrel and threatening the industry recovery that has helped lift the Texas and Houston economies and brought back thousands of oil and gas jobs. The prices, the lowest since Nov. 14, are moving into territory that could make U.S. shale drillers think twice about plans to boost investments and output as they head toward record production by the end of next year.

"There's crude oil everywhere, man," said Robert Yawger, director of the futures division at Mizuho Securities. "That's the fundamental problem."

OPEC's decision in November to curb output by 1.2 million barrels a day - supplemented by a 600,000-barrel a day cut by Russia and other major producers - pushed prices higher and spurred new production by U.S. shale drillers, who spent the downturn becoming more efficient and learning to make money at lower prices.

As the second shale boom has gained momentum, particularly in Texas oil fields, investors have lost faith in both the OPEC agreement and the cartel's ability to realign global supply and demand.

U.S. production is expected to reach 10 million barrels a day in 2018, coming close or breaking the 1970 record; new data released this week by OPEC show its oil production climbed by 336,000 barrels a day last month, its biggest increase since December. That was largely due to production recovering in Libya and Nigeria, two war-torn countries exempt from OPEC's agreement.

Adding to market jitters is slipping U.S. demand. Gasoline consumption is down about 1 percent from a year ago, and inventories climbed by 2.1 million barrels, more than offsetting a 1.7 million barrel decline in crude stockpiles, the Energy Department reported.

Inventories of all petroleum - including crude, fuels and other refined products - climbed 6.8 million barrels.

Analysts and energy companies, meanwhile, worry that slumping gasoline demand is more than a blip. After the Great Recession in 2009, the number of miles Americans drive each year has continued to fall, and car makers have designed vehicles with greater fuel efficiency.

"At the same time that people are driving less, you've got vehicles with increasingly better mileage," said Bill O'Grady, executive vice president at Confluence Investment Management, a St. Louis investment firm. "There do appear to be some structural issues. Millennials are less enamored of driving than previous generations, and that coupled with the fact that baby boomers are retiring seems to have had a permanent effect on miles driven."

Globally, low oil prices in recent years have bolstered global demand for crude above average levels. But demand growth in 2017 isn't expected to rise as high as it did last year, analysts said.

Demand could accelerate next year, but it's likely to be met by increasing oil production that will hold down prices. The Energy Department believes U.S. oil prices will edge up to an average $53.61 a barrel next year - around the same price it was in January and February.

In its monthly report Wednesday, the International Energy Agency said even with OPEC's cuts, climbing oil production from oil fields in West Texas and Oklahoma to Canada and Brazil will grow by 1.5 million barrels a day - more than projected global demand growth next year.

"Stocks might not fall to the desired level until close to the expiry of the (OPEC) agreement in March 2018," the IEA said. "A lot can change of course, but, as we said at the start, 2018 seems a very long way away."