Feb. 1 (UPI) -- The Permian shale oil basin in the southern United States is among the few to show gains even during the market downturn, a federal report finds.

Overall, the shale oil basins in the United States have been more resilient than expected during the market downturn that began in mid-2015. In a recent forecast, the U.S. Energy Information Administration predicted a slight increase in total U.S. oil production for 2017, a reversal of estimates last year that forecast a decline.

Texas remains the No. 1 oil producer in the United States and the EIA said in a daily briefing that the Permian shale basin is the most durable in the country.

"Although overall U.S. oil production has been declining since mid-2015, production has continued to increase in the Permian region," the report read.

By EIA estimates, total Permian production last year was 5 percent above 2015 levels and is on pace to increase up to 15 percent this year.

Because of its large geographical size, EIA said Permian is a stand out because of heightened drilling potential.

Nearly half of all the activity in exploration and production in the United States took place in Texas

Elsewhere, the Eagle Ford region, which covers far less area than the Permian shale, has seen declining interest and activity. According to EIA, wells in Eagle Ford peak early and production has been in decline since early 2015.

Higher oil prices, however, should keep Eagle Ford in play at least through 2018 as market recovery improves the economics for other shale basins.

Emerging U.S. shale player Halcon Resources was the latest to reshuffle its deck in Texas by acquiring more acreage in the Permian shale after unloading assets in Eagle Ford. Anadarko Petroleum in late January agreed to sell off its assets in the Eagle Ford shale basin in Texas to Sanchez Energy Corp. and Blackstone Group for $2.3 billion.