Gran Tierra Bids on 3 Blocks in Colombia

Gran Tierra announced successful bids on three blocks in the recently completed 2010 Colombia Bid Round administered by Colombia's National Hydrocarbon Agency (ANH). The open and competitive process was available to those pre-qualified by the ANH and successful bid contracts are expected to be finalized by October 2010.

"These successful bids expand Gran Tierra's exploration portfolio," said Dana Coffield, President and Chief Executive Officer of Gran Tierra. "Putumayo 10 will enable us to leverage existing knowledge of our Piedemonte Norte and Piedemonte Sur Blocks, while Cauca 6 and 10 provide new frontier exploration opportunities for the company."

Putumayo 10 is located close to Gran Tierra's core existing areas in the Putumayo Basin of southern Colombia and offers exploration opportunities expected to be similar to the company's Piedemonte Norte and Piedemonte Sur exploration blocks. This Block captures additional acreage on a structural trend that will enable Gran Tierra to leverage existing knowledge from the Chaza Block, with the recently developed Costayaco Field and adjacent potential discovery at Moqueta-1. Multiple leads have already been identified on these blocks based on existing data with additional seismic acquisition planned for 2011 in preparation for 2012 drilling. The Block encompasses 114,097 net acres of land under an initial 3 year exploration period, during which Gran Tierra Energy is committed to drill two exploration wells and acquire 70 kilometers of 2D seismic data.

The Cauca 6 and 7 Blocks encompass frontier exploration acreage in the southern portion of the Cauca Basin in southern Colombia approximately 100 kilometers north of the Putumayo Basin. The Cauca 6 Block encompasses 571,197 net acres of land and has an initial three year exploration period with a commitment to drill one well along with 200 kilometers of 2D seismic acquisition, while the Cauca 7 Block encompasses 785,450 net acres of land with a commitment to drill one well and acquire 250 kilometers of 2D seismic data in the initial three year exploration period. This vast exploration acreage encompasses a fold and thrust belt similar to that found in the Putumayo Basin, with Cretaceous and Tertiary reservoir objectives and surface oil and gas seeps. The blocks contain a loose grid of old 2D seismic data, but it has never been drilled. New 2D seismic data may be acquired in 2011, with drilling expected to follow in 2012 or 2013.

Including the blocks awarded in the bid round, this brings Gran Tierra's gross land acreage under contract to approximately 2.5 million gross acres in Colombia. This is in addition to approximately 3.4 million gross acres in Peru and 1.6 gross acres in Argentina, for a total company gross acreage of approximately 7.6 million acres.

Operations Update

Due to a recent disruption of the Ecopetrol operated OTA pipeline, production from the Putumayo Basin has been reduced. Current production is expected to be maintained between 4,000 to 7,000 barrels of oil per day while pipeline repairs are made. Repairs are expected to take approximately two weeks.

The drilling rig from the recently drilled Moqueta-1 exploration well has been released and is being moved in preparation to drill Moqueta-2, a delineation well to be drilled directionally from the Moqueta-1 location. Test results from Moqueta-1 are expected to be released shortly.