The number of barrels of oil produced per day in North Dakota set a record in December, but the tally of rigs in the oil patch has dropped precipitously since then, state regulators said Friday.

The state’s Mineral Resources Department estimated December production at slightly more than 38 million barrels, or about 1.23 million barrels per day. That broke the November record of 1.19 million barrels per day.

However, the drilling rig count dropped from 188 in November to 181 in December and continued to fall, to 137 on Friday — a 37% drop from the record high of 218 rigs on May 29, 2012, and the lowest number since July 2010.

“Oil price is by far the biggest driver behind the slowdown,” Mineral Resources Director Lynn Helms said.

The price of oil has plummeted since last summer due to rising production in the U.S. and elsewhere.

Wasteful burning off of natural gas — a byproduct of oil production — declined 1% from November to December in North Dakota, to 24% of production.

The percentage of flared natural gas had been about one-third of production over the past several years but dropped after regulators endorsed a policy last summer that sets goals to reduce flaring in incremental steps through 2020. The new rules allow regulators to set production limits on oil companies if the targets are not met.

December estimates are the latest available because oil production numbers typically lag at least two months.

Source: PennEnergy