Exploratory activities showed a rebound in 2004, not only due to the increase in the budget for the search for new reserves, but also because new contracts were signed.

Seismic acquisition more than fulfilled its established
goal, and studies were begun to increase Ecopetrol’s share of the international market.

In late 2004, 188.4 million barrels of oil equivalent, MBOE, were incorpored, of which 32 MBOE correspond to commerciality and 156.4 MBOE as a result of technicaleconomical revaluations of existing fields (96.4 oil and 60 gas).

The principal result in exploration was the volume of hydrocarbons proven at the Gibraltar field, which reached 120 in MBOE, 630 cubic giga feet (billions) of gas and 15 million barrels of oil. This volume will not be incorporated into the reserves until a commercialization scheme has been defined. Long-term tests at the Gibraltar-2 well made it possible to determine with a high degree of certainty (90%) the proven volume based on the behavior of the structure related to the Gibraltar-1 and Gibraltar-2 wells. This volume does not include the southern part of the structure, which could have additional hydrocarbon potential. The reason is that there is less information available on this zone and it has not been delimited.

Discoveries during the year reached approximately 16 MBOE (contingent reserves, based on the best estimates of the results from eight exploratory producer wells). These resources have not yet been counted within the reserves, pending completion of tests and definition of the commercialization scheme.

During this period, 6,767 equivalent km of seismic information were recorded, 192% more than in 2003 and 322% greater than 2002. Particularly noteworthy is the multi-client seismic acquisition at the Colombian Caribean offshore area, which