Gran Tierra Doubles Net Argentina Production

Gran Tierra Energy Inc. on Tuesday 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."

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.