We hereby announce the volume of the proved oil reserves (oil, condensate, and natural gas), calculated in late 2016 pursuant to the criteria set forth by ANP/SPE (National Petroleum Agency/Society of Petroleum Engineers) and SEC (the US Securities and Exchange Commission).
According to ANP/SPE criteria, at December 31, 2016, our proved oil, condensate and natural gas reserves amounted to 12.514 billion barrels of oil equivalent (boe), as shown below. In 2015, these volumes were 13.279 billion boe.
Our oil, condensate, and natural gas volumes in Bolivia do not appear because the country's constitution does not allow concessionaires to disclose the reserves.
The following table shows the evolution in proved reserves in 2016.
The main factors affecting the reserves were:
• Incorporation of 0.110 billion boe of proved reserves, mainly due to the drilling of new wells in Búzios field (Santos Basin);
• Increase of 0.203 billion boe in proved reserves resulting from the drilling of new production development wells and from the improved behavior of the reservoirs areas located onshore and offshore in the post-salt layer in Brazil and in the USA. In the pre-salt, the increase was the outcome of positive responses in reservoir behavior, recovery mechanisms (water injection), and in the operating efficiency of the production systems in operation, as well as of the increased drilling and well interconnection activity in the Santos and Campos Basins, both in Brazil;
• Divestments that provided the early monetization of 0.153 billion boe of Petrobras' reserves in Argentina and Venezuela;
• Production of 0.925 billion boe in 2016. This volume includes the production of shale, but does not include the volume lifted in Extended Well Tests (EWT) and production in Bolivia. The EWTs take place in exploration areas where the field’s commerciality has not been declared and, thus, for which there is no associated reserve and, in the case of Bolivia, the country's constitution does not allow concessionaires to register the reserves.
We presented a 34 percent Reserve Replacement Index (RRI), excluding the effects of the divestments made in 2016. The reserve volume and volume produced ratio is 13.5 years, 13.9 years in Brazil. The Development Index (DI), the ratio of proved developed reserves and proved reserves, stood at 50 percent in 2016.
According to the SEC criterion, at December 31, 2016, our proved oil, condensate and natural gas reserves amounted to 9.672 billion barrels of oil equivalent (boe), as shown below. In 2015, these volumes were 10.516 billion boe.
The evolution of proved reserves appears in the following table:
The same highlights previously made for the proven reserves according to the ANP/SPE criteria apply to the proved reserves according to the SEC criteria.
The main difference between the ANP/SPE and SEC criteria is the price of the oil considered in the calculation of the reserves’ economic feasibility.
Based on the SEC criterion, we had a 25% Reserve Replacement Index (RRI), excluding the effects of the divestments made in 2016. The reserve volume and volume produced ratio is 10.5 years, 10.7 years in Brazil. The Development Index (DI) was 54 percent in 2016.
It is worthy of note that, historically, we have certified about 95 percent of its proved reserves pursuant to the SEC criteria. The certifying company is currently D&M (DeGolyer and MacNaughton).