16 Enero 2007

Gran Tierra Well Test Flows Up To 2,800 BOPD in Argentina; Production Sales Initiated

CALGARY, Alberta, January 16, 2007, Gran Tierra Energy Inc. (OTC Bulletin Board: GTRE.OB) today announced that the Company has successfully completed testing of a deeper oil pool accumulation with the Puesto Climaco-2D (D-2) well, a new sidetrack well drilled in the Vinalar block, located in the Noroeste Basin of northern Argentina. Gran Tierra holds a 50% working interest in this block.

Puesto Climaco-2D (D-2) reached total measured depth of 3,720 meters (3,612 true vertical depth) on January 4, 2007. The well encountered reservoir with good hydrocarbon shows in five zones. Three of the zones are proven reservoirs (22.5 meters of potential net pay); the other two zones are unproven reservoirs (13 meters of potential net pay). The hole was cased and logged, and the Puesto Guardian sandstone was perforated from 3,650-3662 meters (measured depth).

Four tests were conducted with four choke sizes; a maximum flow rate of 2,825 BOPD (gross before royalty) of light oil was attained through a 35/64 choke. Flowing tubing pressure measured at the wellhead was consistent throughout at 1,720-1,750 psi. Testing is finished and the drilling rig is being demobilized.

Production and oil sales have begun through infrastructure already in place; gross production volumes are currently stabilized through a 16/64 choke at approximately 1,200 BOPD (600 BOPD net before royalty to the Company). An evaluation of new reserves associated with this reservoir is pending, as reservoir performance continues to be monitored. The shallower formations with hydrocarbon shows are being considered for testing at a future time.

Dana Coffield, President and Chief Executive Officer of Gran Tierra, stated “This is an outstanding success for our first operated drilling program in Argentina; this well doubles our current net after-royalty production in Argentina, and establishes a second material production center in the Noroeste Basin for Gran Tierra Energy. This is the first of six wells Gran Tierra Energy will be drilling in the next three months, and part of a ten well program being drilled in Argentina and Colombia this year.”

About Gran Tierra Energy Inc.
Gran Tierra Energy, Inc. is an international oil and gas exploration and production company, headquartered in Calgary, Canada, incorporated and traded in the United States and operating in South America. The Company holds interests in producing and prospective properties in Argentina, Colombia and Peru. To date, the Company has pursued a strategy that focuses on establishing a portfolio of producing properties, development and exploration opportunities, through selective acquisitions, to provide a base for future growth. Additional information concerning Gran Tierra is available at www.grantierra.com. Investor inquiries may be directed to info@grantierra.com or 1-800-916-GTRE (4873).

Forward Looking Statements
This press release contains ‘forward-looking statements’ within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, including without limitation those statements regarding the Company’s ability to exploit oil and gas exploration opportunities. These statements are expressed in good faith and based upon a reasonable basis when made, but there can be no assurance that these expectations will be achieved or accomplished. Although the forward-looking statements in this release reflect the good faith judgment of management, forward-looking statements are inherently subject to known and unknown risks and uncertainties that may cause actual results to be materially different from those discussed in these forward-looking statements including, but not limited to, our ability to complete the Company’s drilling program for 2007, our ability to discover reserves that may be extracted on a commercially viable basis, difficulties inherent in estimating oil and gas reserves, intense competition in the oil and gas industry, environmental risks, regulatory changes and general economic conditions including the price of oil and gas. Readers are urged not to place undue reliance on these forward-looking statements, which speak only as of the date of this release. We assume no obligation to update any forward-looking statements in order to reflect any event or circumstance that may arise after the date of this release, other than as may be required by applicable law or regulation. Readers are urged to carefully review and consider the various disclosures made by us in the our reports filed with the Securities and Exchange Commission, including those risks set forth in the Company’s Annual Report on Form 10-KSB filed on March 10, 2006, as amended, which attempt to advise interested parties of the risks and factors that may affect our business, financial condition, results of operation and cash flows. If one or more of these risks or uncertainties materialize, or if the underlying assumptions prove incorrect, our actual results may vary materially from those expected or projected. We undertake no obligation to update these forward looking statements.