Argentina’s oil production rose to 571,000 bbl/d in February, up 14% year-on-year driven by shale oil output, marking the highest level since the end of 2011, the energy secretariat said on March 21.

Production in the South American country’s huge Vaca Muerta Shale formation led the increase, with unconventional oil output rising 55% and making up 39% of the total, or 222,000 bbl/d. Vaca Muerta is the world’s fourth largest shale oil reserve.

The country is looking to ramp up domestic production of oil and gas to trim increasingly expensive imports, a drive that has gained momentum due to rising global energy costs that are being pushed even higher by the war in Ukraine.

“These production levels are very important for the country, especially at this time with the global energy crisis resulting from the war which will affect everyone, including Argentina,” Energy Secretary Darío Martínez said in a statement.