CALGARY, April 11, 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 Colombia. 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 (" MD") in basement. Gran Tierra Energy, along with its operating partner Compania Espanola de Petroleos, S.A.U. (" CEPSA"), has completed initial testing on Ramiriqui-1 by collecting reservoir data and fluid samples from the Mirador formation. The Mirador formation has 130 feet gross thickness and was perforated and tested from 17,610 feet to 17,630 feet MD in the uppermost primary reservoir interval. The interval had natural flow rates, without pumps, of up to 2,525 barrels of oil per day ("BOPD") gross over 32.5 hours with a 28/64 inch choke and a 0.12% watercut with 26°API gravity oil. The Ramiriqui-1 well flowed at a restricted rate due to gas flaring limitations. The partners are currently evaluating options for testing additional reservoir intervals, drilling of an appraisal well, and implementation of an early production program. "We are extremely pleased with the early success of Gran Tierra Energy's 2012 exploration drilling program, building on our growing reserves and production base in the Llanos Basin." said Dana Coffield, President and Chief Executive Officer of Gran Tierra Energy. "This is the first of four exploration wells planned for this year in Colombia, with two in the Llanos Basin and two in the Putumayo Basin. In addition, one exploration well in Peru, two exploration wells in Brazil and three exploration wells in Argentina are planned through the balance of the year." Azar Block, Putumayo Basin (Gran Tierra Energy 40% WI and Operator, Lewis Energy Colombia Inc. 40% WI, Gold Oil 20% WI subject to Agencia Nacional de Hidrocarburosapproval) Civil construction has commenced for the La Vega Este-1 oil exploration well. The drilling rig is expected to mobilize from the Costayaco-15 well site to the La Vega Este-1 wellsite and is expected to begin drilling in late April, 2012. The La Vega Este-1 well is targeting the same Cretaceous Sandstone intervals present in the Costayaco and Moqueta discoveries.