NEW YORK ( TheStreet) -- Natural gas futures surged after the government reported a lighter-than-expected buildup in storage levels Thursday.

According to the Energy Information Administration's weekly assessment, natural gas storage in the lower 48 states saw a net injection of 73 billion cubic feet, raising levels to 1.829 trillion cubic feet for the week ending April 16. Analysts surveyed by Platts had expected inventory to rise between 76 to 80 billion cubic feet.

"We got spring fever a little too early," said Phil Flynn, energy analyst at PFGBEST. "The whisper number was a little higher than it should have been," he added, noting many overestimated the injection in light of recent warming temperatures around the country.

But despite the smaller buildup, natural gas levels remain higher than normal when compared to historical figures. According to the report, storage levels are 5.5% higher when compared with year-ago marks, and remain 18.5% higher when up against the five-year average.

Natural gas futures, which were trading lower just before the report's release, rose as high as $4.15 per million British thermal units during the day's session before settling higher by 17 cents, or 4.4%, at $4.13 per million British thermal units.

The U.S. Natural Gas Fund ( UNG) also soared following the news, gaining 3.7% on the day.

Crude oil futures, however, mostly traded around $83 a barrel, a day after the EIA separately reported a larger-than-expected buildup in oil and fuel supplies. The June delivery contract slipped as low as $81.73 despite trading briefly above $84 a barrel, hitting $84.07 at its highest point of the session. The contract finished close to where it started, adding 2 cents, or 0.02%, to settle at $83.70 a barrel.

Flynn also noted a number of other catalysts affecting crude prices. Concerns about Greece's debt level weighed on the euro and strengthened the dollar, while the nation's wholesale inflation measure reflected a hotter-than-expected uptick in prices during March. Rising prices could signal a Federal Reserve rate hike in the near future, which could stifle economic growth.

"Then there's inventories. There, we're loaded," Flynn said. "It's getting harder and harder to ignore those numbers every week," later adding "if this isn't a glut, I don't know what is."

The U.S. Oil Fund ( USO) ETF finished mildly higher, up by 0.07%.

Among related equities, the NYSE Arca Oil index was slipped 0.5%, while the Philadelphia Oil Service Sector index rose 1.6%.

Chevron ( CVX) and Exxon Mobil ( XOM) were among the handful of stocks putting the most pressure on the Dow Jones Industrial Average, which turned positive in the last half-hour of trading. Chevron fell 0.9% while Exxon lost 0.5%.

Earlier, Diamond Offshore Drilling ( DO) said earnings backtracked from year-ago levels, but it neverthless managed to surpass forecasts. Still, the offshore contractor cut its special dividend, tying it to an expected "decline in renewal contract dayrates from peak levels," according to the release, which sent shares tumbling to finish 5.4% lower.

ENSCO ( ESV) shares gained 4.1% on the day after the driller announced upbeat first-quarter earnings and an increased dividend.

Oilfield services company Schlumberger ( SLB) is scheduled to report first-quarter earnings Friday morning. Analysts are anticipating a profit of 61 cents a share. Its stock added 0.2% ahead of the report.

Also on the Nymex, June heating oil added a penny, or 0.5%, to settle at $2.24 a gallon. The June gasoline contract also finished a penny higher, or up by 0.6%, to settle at $2.31 a gallon.

-- Written by Sung Moss and Melinda Peer in New York.

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