Initial logs indicate oil encountered at the Moqueta-12 and Mayalito-1 wells in Colombia; First Shipment of Gran Tierra Energy oil sold through the Port of Esmeraldas, EcuadorCALGARY, Dec. 3, 2013 /PRNewswire/ - Gran Tierra Energy Inc. ("Gran Tierra Energy") (NYSE MKT: GTE) (TSX: GTE), a company focused on oil exploration and production in South America, today provided updates for its operations in Colombia. "Gran Tierra Energy continues its successful 2013 drilling program with encouraging initial data from the Moqueta-12 and Mayalito-1 wells in the Putumayo and Llanos Basins in Colombia. Moqueta-12, based on log interpretations, does not appear to have encountered any water, suggesting we have yet to define the boundaries of the Moqueta field. Similarly, Mayalito-1 log interpretations indicate oil has been found in the Mirador formation, further extending the known lateral extent of the oil accumulation in the Ramiriqui discovery," said Dana Coffield, President and Chief Executive Officer of Gran Tierra Energy. "In addition, Gran Tierra Energy's 2013 exploration drilling has increased significantly with the Corunta-1, Miraflor West-1 and Zapotero-1 exploration wells initiating drilling in the Putumayo Basin," concluded Coffield. ColombiaChaza Block, Putumayo Basin (Gran Tierra Energy 100% Working Interest (" WI") and Operator) Initial drilling and logging results have been obtained from the Moqueta-12 delineation well. Oil and gas shows encountered during drilling and log interpretations from data acquired after drilling, indicate the presence of oil-bearing reservoir sandstones in the Villeta T Sandstone beginning at 5,545 feet measured depth (" MD") or 4,825 feet true vertical depth (" TVD") with an approximate potential net oil pay thickness of 141 feet MD. The underlying Caballos formation was encountered at 5,818 feet MD or 5,066 feet TVD with approximately 201 feet MD of potential net pay interpreted from the well logs. Another planned objective for the Moqueta-12 well was to target a structure south of the main Moqueta field. The Moqueta-12 well was unable to intersect this sub-block due to steeper bedding planes than anticipated. This objective will be tested at a later date once the global development permit is received. The Moqueta-12 bottom hole location is approximately 1,300 feet west of Moqueta-11 and the lowest interpreted oil pay is approximately 150 feet lower than the lowest known oil encountered at Moqueta-11. Testing is underway to confirm the fluid content and productivity of the encountered zones and is expected to be completed in December. If successful, this well is expected to add additional reserves to the resource base of this growing field.