The company said proven net hydrocarbon reserves were 1.9 billion barrels of oil equivalent at the end of 2013, a 5.1 percent increase from 2012 and "the highest ever in the company's history."
"The increase in proven reserves is mainly the product of revisions at existing fields, including the contribution of projects featuring improved recovery and exploratory results [in Colombia]," the company said in a statement Tuesday.
Colombia's oil production has increased steadily since 2008 because of increased exploration activity.
The country's central provinces are key production areas, giving up mostly heavy crude oil. The Energy Information Administration, the analytical arm of the Energy Department, said Colombia had approximately 2 billion barrels of proven crude oil reserves as of 2012.