Ecopetrol announced its proven reserves (1P, according to the international designation) of crude oil, condensate and natural gas owned by the company, including its interest in affiliates and subsidiaries, as of December 31, 2015.
The reserves were estimated based on the U.S. Securities and Exchange Commission (SEC) standards and methodology. 99% of them were audited by two well-known specialized independent companies (Ryder Scott Company and DeGolyer and MacNaughton).
Ecopetrol's Proven net hydrocarbon reserves were 1,849 million barrels of oil equivalent (mmboe) at the close of 2015, an 11% reduction compared with 2,084 mmboe at the end of 2014. The reserve replacement ratio was 6%, and the reserves/production ratio (average life of reserves) was 7.4 years.
The reduction in proved reserves was mainly driven by the plunge of hydrocarbon prices. In 2015, SEC price for Brent was US$55.57 per barrel compared to US$101.80 per barrel in 2014.
Ecopetrol estimates that the price effect implies a decrease of 404 mmboe in reserves during 2015 compared with those from the end of 2014. This decrease was largely offset by the addition of 275 mmboe, attributable to cost optimizations and higher efficiencies achieved by the Company as well as by the addition of 67 mmboe as a result of the new drilling campaigns in Castilla and Rubiales fields, and the positive revisions of some fields like Chichimene, due to good production performance. Another positive effect came from the inclusion of natural gas self-consumption on proved reserves (+47 mmboe).
The highest contributions to the reserve balance were from Castilla and Chichimene fields, both directly operated by Ecopetrol, and from Rubiales field, which will be operated by Ecopetrol as of July 2016.
95% of our proved reserves belong to Ecopetrol S.A., while Hocol, Ecopetrol America and the participation in Equion and Savia Peru contributes with 5%.