Ecopetrol Commences Commercial Production at Casaba Sur Field

Ecopetrol has declared the commercial viability of Casabe Sur field, located in the municipality of Yondo, Antioquia, Colombia following confirmation of its potential through tests performed on four wells.

The statement of commercial viability means that, after evaluating the results of the exploratory phase and testing stages, Ecopetrol confirms the potential of the field and decides to begin the commercial production stage.

The field has a commercial area of 305 hectares and is owned 100% by Ecopetrol. The original volume of hydrocarbons in situ is estimated to be 62 million barrels, of which unaudited proven oil reserves are calculated to be 5.4 million, with 9.9 million barrels of probable reserves.

The field's current output is 1,600 barrels of crude per day (bpd). The development plan calls for increasing such output to 5,500 bpd by 2012 with the application of secondary recovery technologies, especially water injection.

The field is operated through a services and technical collaboration contract for the area of Casabe between Schlumberger and Ecopetrol.

The commercial viability of the Casabe Sur field contributes to Ecopetrol's strategy of incorporating reserves in areas surrounding production fields and helps reach the Company's production goal of one million barrels of oil equivalent (oil and gas) per day by 2015 and one million three hundred thousand barrels of oil equivalent per day by 2020.