Gran Tierra Energy announced that it has increased the oil reserves assessment at its Costayaco field in southwestern Colombia by 33%.
The company attributed the change in its original oil-in-place estimate to its use of lower water saturation data and additional production history and pressure data. The reservoir has also had a strong response to water injection, which should help maintain the production plateau, the company said.
Compared with the assessment at the end of last year, and adjusted for production during the first half of this year, total proven reserves in the Chaza block of the field’s Putumayo Basin have increased by 4.9 million bbl to about 19.6 million bbl of oil. Gran Tierra is the operator and 100% stakeholder in the block.
At the nearby Moqueta field in the same basin, the company said it has acquired 3D seismic data, which indicates additional oil reserve potential in the east flank of the geological structure. A new evaluation well will be spudded in the area in September. Another Moqueta appraisal well will be spudded this month to evaluate additional down-dip potential of the oil columns in the Villeta U, Villeta T, and Caballos reservoirs.
In northeastern Colombia, Gran Tierra also confirmed an oil discovery in the Llanos 22 block in the Llanos Basin, with a well test flow rate of 2,525 gross BOPD. It holds a 45% interest in the block with operator Cepsa (55%).
