NEW YORK (CNN/Money) - The supply of crude oil in the United States dropped by 9.1 million barrels last week, the government reported Wednesday, falling far more than experts had expected.

Oil inventories fell by 3.3 percent to 269.5 million barrels in the week ended Sept. 17, the Energy Information Administration (EIA) reported. Analysts had expected a drop of 5.5 million barrels, according to Reuters.

Following the EIA report, trading in U.S. light crude for November delivery was very volatile with the price initially jumping, then sliding back below Tuesday's closing price. At 11:23 a.m. ET, light crude was up 44 cents to $47.20 a barrel.

"With dramatic inventory news like this, you're going to see prices swing," said Richard Mueller, senior oil analyst with energy research firm ESAI.

The severe hurricane season that has mauled the Caribbean and U.S. Gulf Coast region disrupted oil shipments in recent weeks.

The EIA said crude imports fell 1.5 million barrels per day to 8.4 million bpd last week, however shipments have averaged 9.8 million bpd over the past four weeks.

Import shortages due to weather are usually followed by a glut as ships that waited out the storms in safer waters reach their ports.

"We're continuing to see OPEC pump huge amounts and I suspect that over the next few weeks, we'll begin to see inventories build as demand switches from gasoline to heating oil, which does not have as much demand," Mueller said.