Brazil’s Petrobras slashed its 2015 proven reserves on Friday by just over 3 billion barrels.
The state-owned company said that, according to ANP/SPE criteria its proven oil, condensate and natural gas reserves fell to 13.279 billion barrels of oil equivalent (boe) as of December 31, down from 16.612 billion boe the previous year.
According to Forbes, 10.9 billion barrels of the company’s reserves are oil and condensate with natural gas reserves sitting at 374.2 billion square cubic meters.
By SEC criteria, Petrobras booked a reduction of 1.692 billion boe in its proven reserves “due to factors other than the extraction of oil and natural gas.”
Petrobras said revisions to reserve estimates at its pre-salt wells were responsible for a majority of the proven reserve decline.
Low oil prices may also be partially to blame for the reserve drop as discoveries become uneconomic to develop at current prices.
According to Reuters, the company’s reserve levels are now at their lowest level since 2001.
Petrobras’s reserves now account for 11.3 years of output, down from 14.7 years in 2014, Reuters added.
Petrobras said in the filing that it produced 932 million boe in 2015, up 4 percent from the previous year.
Last week, Petrobras announced that it will reduce its management headcount by at least 30 percent in an effort to cut costs.
The company, currently the most indebted oil firm in the world, expects the reductions to produce about $442 million per year in savings.
A timeline for the layoffs has not been disclosed yet.
Petrobras also adjusted its 2016 investment budget down to $20 billion last month from the initial $27 million budget included in its 2015-2019 Business and Management Plan.