The Orca-1 well is located in the Tayrona block. The partners are Petrobras (operator with 40%), Ecopetrol (30%) and Repsol (30%).

Drilling reached a depth of 4,243 meters and confirmed an accumulation of natural gas.

BOGOTA, Colombia, Dec. 2, 2014 /PRNewswire/ — Ecopetrol S.A. (BVC: ECOPETROL; NYSE: EC; TSX: ECP) announces the discovery of hydrocarbons in the exploratory Orca-1 well, located 40 kilometers north of the coast of Guajira province. This is the first discovery in deep waters of the Colombian Caribbean.

Ecopetrol S.A.

The Orca-1 well was drilled within the Tayrona block and has as its operating company Petrobras, with a 40% stake, in partnership with Ecopetrol (30%) and Repsol (30%). The Tayrona block was the first contract granted in 2004 by the National Hydrocarbons Agency (Agencia Nacional de Hidrocarburos) for exploration in the Colombian Caribbean.

The well reached the expected depth of 13,910 feet (4,243 meters), in water depth of 2,211 feet (674 meters). Drilling was completed in September and showed the accumulation of natural gas at a depth of 12,000 feet (3,657 meters).

Orca-1’s results confirm the hydrocarbon potential of this Colombian frontier basin and demonstrate the capacity of the petroleum system in the deep part of the offshore basin.

Following completion of this phase of exploration and initial tests, in-depth technical studies will begin to determine gas potential of the discovery.

Ecopetrol is currently a participating partner in 13 offshore blocks in the Colombian Caribbean. A drilling campaign is planned for this basin that will include two wells in 2015 and two or three additional wells in 2016 with its partners.

Ecopetrol is the largest company in Colombia and is integrated into the oil chain; it is among the 50 major oil companies in the world and among the four main ones in Latin America. Besides Colombia – where it generates over 60% of the national production – it is present in exploration and production activities in Brazil, Peru & US (Gulf of Mexico). Ecopetrol owns the largest refinery in Colombia and most of the pipeline and multi-product pipeline network in the country, and is significantly increasing its participation in bio-fuels.

This report contains statements associated with the business perspectives, estimates for operational and financial outcomes and affirmations associated to Ecopetrol’s growth. All the above are projections, and as such are solely based on the expectations of its directors with respect to the future of the company and its ongoing access to capital to fund the company’s commercial plan. The realization of such estimates in the future depends on market conditions, regulations, competitiveness, performance of Colombia’s economy and industry, to mention a few; therefore, they are subject to changes without previous notice.

For further information, please contact:

Investor Relations Director

Alejandro Giraldo

Phone: +571-234-5190

e-mail: [email protected]

Media Relations (Colombia)

Jorge Mauricio Tellez

Phone: + 571-234-4329

Fax: +571-234-4480

e-mail: [email protected]