Petroleo Brasileiro SA PBR or Petrobras, one of the largest integrated energy firms in Latin America, announced that the unit extraction costs from the Brazil's Subsalt Polygon declined about 7% in 2015.Precisely, unit extraction costs declined from $9.10 a barrel of oil in 2014 to $8.50 a barrel in 2015. The decline is extraction costs should benefit Petrobras, which is currently the world's most indebted major oil company with more than $130 billion in liabilities. Lower extraction costs should provide some relief to the company’s already stretched finances.The Subsalt Polygon – located in the Atlantic offshore Sao Paulo and Rio de Janeiro – is estimated to contain at least 176 billion barrels of oil and natural gas. This amount is enough to meet the demands of the entire world for these commodities for five years and more. Also, this amount is more than four times the 30–40 billion barrels of oil and natural gas already discovered in the area.Petrobras’ financials have been severely affected by the ongoing oil price slump. Notably, crude oil price has nosedived from the $100 per barrel mark Jun 2014 to the current trading level of around $39 per barrel. Also, Petrobras’ goodwill as well as share price has been severely affected by its involvement in a multi-billion dollar money laundering and bribery case.In Feb 2016, a bill was passed by the Brazilian Senate that ended the requirement for Petrobras to operate all new developments in Subsalt Polygon and provide at least 30% of investment. This bill, along with the recent decline in oil extraction costs, will not only relieve the state oil firm of a huge financial burden but also help it in reducing debt levels.Headquartered in Rio de Janeiro, Petrobras is engaged in the exploration, development, and production of crude oil, natural gas liquids, and natural gas. Additionally, the company sells crude oil and oil products produced at natural gas processing plants in domestic and foreign markets. It is also involved in the refining, logistics, transport, and trading of crude oil and oil products. Moreover, the firm exports ethanol and invests in petrochemical companies.Currently, the company carries a Zacks Rank #3 (Hold), implying that it will perform in line with the broader U.S. equity market over the next one to three months.Some better-ranked players from the energy sector are Vanguard Natural Resources, LLC VNR, OMV Aktiengesellschaft OMVJF and PetroChina Co. Ltd. PTR. All these stocks sport a Zacks Rank #1 (Strong Buy).Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report PETROBRAS-ADR C (PBR): Free Stock Analysis Report PETROCHINA ADR (PTR): Free Stock Analysis Report OMV AG ADS (OMVJF): Free Stock Analysis Report VANGUARD NATURL (VNR): Free Stock Analysis Report To read this article on Zacks.com click here.