Drilling Programs Advance in Colombia and Brazil, Production UpdateCALGARY, March 29, 2012 /PRNewswire/ - Gran Tierra Energy Inc. ("Gran Tierra Energy") (NYSE Amex: GTE) (TSX: GTE), a company focused on oil exploration and production in South America, today provided updates for its operations in Argentina, Colombia and Brazil. ArgentinaSurubi Block, Noroeste Basin (Gran Tierra Energy 85% WI and Operator, Recursos y Energia de Formosa S.A. 15% WI) Gran Tierra Energy has completed drilling and testing the Proa-2 appraisal well, the second well in the Proa oil field. The successful well encountered approximately 31 meters of net pay in two Palmar Largo intervals. Production tests were performed on the two intervals independently, resulting in combined natural flow rates of 6,300 barrels of oil per day (" BOPD") gross of 46° API oil with no water cut. The well is expected to be on production in April, 2012, initially at approximately 2,000 BOPD gross to further analyze reservoir performance while additional transportation capacity is evaluated. ColombiaLlanos-22 Block, Llanos Basin (CEPSA 55% WI and Operator, Gran Tierra Energy 45% WI subject to Agencia Nacional de Hidrocarburosapproval) The Ramiriqui-1 oil exploration well in the Llanos-22 block, located in the Andean foothills trend of the Llanos Basin, has reached total depth at 19,519 feet measured depth in basement. A testing program has been designed to test the reservoir and hydrocarbon character of the zones with oil shows encountered during drilling the Mirador Formation. Results from this testing are expected in April, 2012. BrazilREC-T-155 Block (Gran Tierra Energy 70% WI & Operator, Alvorada 30% WI) The 3-GTE-03D-BA and 3-GTE-4DPA-BA appraisal wells, located 1.2 kilometers north and 0.70 kilometers south of the 1-ALV-2-BA oil discovery well respectively, are scheduled to be tested and expected to be on production by June, 2012. In addition, Gran Tierra Energy is currently preparing the necessary Agência Nacional de Petróleo, Gás Natural e Biocombustíveis documents for the declaration of commerciality and the plan of development for the field.