U.S. shale oil production is expected to dip below 5 million barrels per day (MMbbl/d) in March for the first time in 18 months on the back of an oil rout that has slashed prices by more than 70% since 2014.

Total output in March is set to fall by nearly 93,000 bbl/d to 4.92 MMbbl/d compared with February, according to the U.S. Energy Information Administration's (EIA) drilling productivity report released on Feb. 8. That marked the eighth consecutive month of declines, data showed, and the first time production is below 5 MMbbl/d since September 2014.

While the numbers show a general dip, the EIA also upwardly revised output from a month ago in a number of major plays, which underscores the resilience of production. That includes 127,000 bbl/d more of Eagle Ford output in February compared with last month's forecast. In the Bakken, the EIA revised output for February up by 28,000 bbl/d.

Bakken production from North Dakota is expected to fall 25,000 bbl/d to 1.1 MMbbl/d, its ninth consecutive fall. New well oil production per rig rose by 2 bbl/d to 737 bbl/d, the highest on record, although the rate of that increase was the smallest since February 2014.

In the Eagle Ford in South Texas, production is expected to drop by 50,000 bbl/d to 1.22 MMbbl/d, the lowest output since December 2013, EIA data showed. New well oil production rose by 8 bbl/d to 812 bbl/d, also the highest on record, with the rate of increase the smallest since November 2014.

In the Permian Basin in West Texas and New Mexico, production is expected to rise 1,000 bbl/d, the smallest monthly increase since May. The shale play, which is considered the largest in the United States, has remained fairly firm despite larger cuts in the Eagle Ford and Bakken. New well oil output has increased steadily, rising by 2 bbl/d in March to 423 bbl/d.

Total natural gas output is expected to drop to 44.3 billion cubic feet per day (Bcf/d) in March, the largest monthly decline since January 2015, according to the EIA forecast.

The biggest regional decline was expected to be in the Marcellus formation in Pennsylvania and West Virginia, down 0.2 Bcf/d to 15.7 Bcf/d.