U.S. crude oil production edged lower in December to 11.85 million barrels per day (bbl/d), its first decline since May 2018, the U.S. Energy Information Administration (EIA) said in a monthly report on Feb. 28.

Production fell 56,000 bbl/d from a record 11.91 million bbl/d in November, the agency said.

While output rose in Texas and North Dakota, the largest onshore oil-producing states, the gains were offset by production declines in the U.S. Gulf of Mexico.

Production in onshore formations in Texas rose by 35,000 bbl/d in the month and in North Dakota by 18,000 bbl/d, while production in the federal waters of the Gulf of Mexico fell by 125,000 bbl/d, according to the report.

Gains in production onshore using technology like hydraulic fracturing, known as fracking, last year propelled the U.S. to be the largest oil producer in the world.

Meanwhile, gross natural gas production in the Lower 48 states rose for an 11th month in a row to an all-time high of 98.0 billion cubic feet per day (Bcf/d) in December, up from the prior record of 97.9 Bcf/d in November, according to the EIA's 914 production report.

That, however, was the smallest monthly increase in gas output since January 2018, when Lower 48 production fell by 1.6 Bcf/d.

In Texas, the nation's largest gas producer, output increased to a record high of 25.7 Bcf/d in December, up 1.3% from the prior all-time high in November. That compares with output of 22.7 Bcf/d in December 2017.

In Pennsylvania, the second-biggest gas-producing state, production slipped to 18.17 Bcf/d in December, down 0.2% from a record high of 18.21 Bcf/d in November. That compares with output of 16.32 Bcf/d in December 2017.

A second oil and gas production and demand report, known as the Petroleum Supply Monthly, will be released on March 8 with December data, due to delays with some data caused by the U.S. government shutdown earlier this year.