Gran Tierra Energy Confirms New Oil Discovery with 2,525 BOPD Production Test at Ramiriqui-1, Colombia

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.

Colombia

Llanos-22 Block, Llanos Basin (CEPSA 55% WI and Operator, Gran Tierra Energy 45% WI subject to Agencia Nacional de Hidrocarburos approval)

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 Hidrocarburos approval)

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.

About Gran Tierra Energy Inc.

Gran Tierra Energy is an international oil and gas exploration and production company, headquartered in Calgary, Canada, incorporated in the United States, trading on the NYSE Amex Exchange (GTE) and the Toronto Stock Exchange (GTE), and operating in South America. Gran Tierra Energy holds interests in producing and prospective properties in Colombia, Argentina, Peru, and Brazil. Gran Tierra Energy has a strategy that focuses on establishing a portfolio of producing properties, plus production enhancement and exploration opportunities to provide a base for future growth.

Gran Tierra Energy's Securities and Exchange Commission filings are available on a web site maintained by the Securities and Exchange Commission at http://www.sec.gov and on SEDAR at http://www.sedar.com.

Forward Looking Statements and Advisories

This news release contains certain forward-looking information and forward-looking statements (collectively, "forward-looking statements") under the meaning of applicable securities laws, including Canadian Securities Administrators' National Instrument 51-102 - Continuous Disclosure Obligations and the United States Private Securities Litigation Reform Act of 1995. The use of the words "expected", "planned", "scheduled", "will" and derivations thereof and similar terms identify forward-looking statements. In particular, but without limiting the foregoing, this news release contains forward-looking statements regarding Gran Tierra Energy's planned and expected drilling operations in Brazil,  Colombia and Peru including, without limitation, anticipated  drilling timelines.

The forward-looking statements contained in this news release reflect several material factors and expectations and assumptions of Gran Tierra Energy including, without limitation: assumptions relating to log evaluations; that Gran Tierra Energy will continue to conduct its operations in a manner consistent with past operations; the accuracy of testing and production results and seismic data; the effects of certain drilling techniques; and the general continuance of current or, where applicable, assumed operational, regulatory and industry conditions. Gran Tierra Energy believes the material factors, expectations and assumptions reflected in the forward-looking statements are reasonable at this time but no assurance can be given that these factors, expectations and assumptions will prove to be correct.

The forward-looking statements contained in this news release are subject to risks, uncertainties and other factors that could cause actual results or outcomes to differ materially from those contemplated by the forward-looking statements, including, among others: unexpected technical difficulties and operational difficulties may occur, or the obtaining of environmental permits may be delayed, which could impact or delay the commencement of drilling, production or testing; geographic, political and weather conditions can impede testing, which could impact or delay the commencement of drilling, production or testing; and the risk that current global economic and credit market conditions may impact oil prices and oil consumption more than Gran Tierra Energy currently predicts, which could cause Gran Tierra Energy to chante its current drilling, production and testing plans. Although Gran Tierra Energy's plans for its ongoing exploration and development and the funding thereof are based upon the current expectations of the management of Gran Tierra Energy, there may be circumstances where, for unforeseen reasons, a change in such plans may be necessary as may be determined at the discretion of Gran Tierra Energy. Should any one of a number of issues arise, Gran Tierra Energy may find it necessary to alter its current business strategy. Further information on potential factors that could affect Gran Tierra Energy are included in risks detailed from time to time in Gran Tierra Energy's Securities and Exchange Commission filings, including, without limitation, under the caption "Risk Factors" in Gran Tierra Energy's Annual Report on Form 10-K filed February 27, 2012. These filings are available on a Web site maintained by the Securities and Exchange Commission at http://www.sec.gov and on SEDAR at www.sedar.com.  The forward-looking statements contained herein are expressly qualified in their entirety by this cautionary statement. The forward-looking statements included in this press release are made as of the date of this press release and Gran Tierra Energy disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as expressly required by applicable securities legislation.

Barrels of oil equivalent ("BOE") may be misleading, particularly if used in isolation. A BOE conversion ratio of 6 Mcf: 1 bbl is based on an energy equivalency conversion method primarily applicable at the burner tip and does not represent a value equivalency at the wellhead.

SOURCE Gran Tierra Energy Inc.