Gran Tierra has completed initial testing of the Moqueta-3 delineation well in the Moqueta new field discovery on the Chaza Block in the Putumayo Basin, Colombia. Oil and gas shows were recorded through the Villeta Lower U Sandstone, the Villeta T Sandstone and the Caballos zones, with electric logs indicating total net oil pay in the Moqueta-3 well increasing to 118 feet, from 44 feet encountered in the Moqueta-2 delineation well. Gran Tierra Energy has a 100% working interest and is the Operator of the Chaza Block.

"The Moqueta-3 delineation well testing has confirmed the increase in oil column thickness and additional oil productivity of the Moqueta field," said Dana Coffield, President and Chief Executive Officer of Gran Tierra Energy. "We are continuing civil construction on the Moqueta-4 well site, located 1.5 kilometers southwest of Moqueta-1. The Moqueta-4 delineation well will allow Gran Tierra Energy to further assess the aerial extent of the Moqueta oil accumulation. In parallel, we are continuing design and permitting for construction of a pipeline to connect Moqueta to existing infrastructure, with the intent to establish first production in the first quarter of 2011."

Moqueta-3 Delineation Well, Chaza Block Gran Tierra Energy has completed initial testing on the Moqueta-3 delineation well by collecting reservoir data and fluid samples from four zones - the Lower Caballos, the Middle Caballos, the Upper Caballos and the Villeta T Sandstone. No testing was conducted in the Villeta Lower U Sandstone zones to preserve the casing integrity for future oil production.

In the Villeta T Sandstone zone, two intervals totaling 48 feet were perforated and tested from 4,549 feet measured depth ("MD") to 4,561 feet MD and from 4,568 feet MD to 4,604 feet MD. Oil flowed without assistance from pumps at 514 barrels of oil per day ("BOPD") with a gravity and watercut of 28.4° API and 0.2%, respectively. No oil-water contact is evident in the Villeta T Sandstone zone penetrated by the well bore.

In the Upper Caballos zone, two intervals totaling 26 feet were perforated and tested from 4,690 feet MD to 4,708 feet MD and from 4,715 feet MD to 4,723 feet MD. Oil flowed with swabbing stimulation at 120 BOPD, with a gravity and watercut of 28.3° API and 0.2%, respectively. No oil-water contact is evident in the Upper Caballos formation penetrated by the well bore.

In the Middle Caballos formation, two intervals totaling 27 feet were perforated and tested from 4,734 feet MD to 4,750 feet MD and from 4,761 feet MD to 4,772 feet MD. Oil flowed with swabbing stimulation at 219 BOPD, with a gravity and watercut of 28.6° API and 0.2%, respectively. No oil-water contact is evident in the Middle Caballos formation penetrated by the well bore.

The Lower Caballos formation was previously determined to have lower oil saturation than Moqueta-1 and Moqueta-2. After low productivity fluid testing, Gran Tierra Energy has preliminary indications the lowermost part of the Lower Caballos is water bearing in the Moqueta-3 delineation well.

Gran Tierra Energy is currently undertaking civil construction at the Moqueta-4 well site, which is located approximately 1.5 kilometers southwest of Gran Tierra Energy's Moqueta-1 well. The Moqueta-4 well is scheduled to spud in early December.

Design and permitting of a six inch diameter, eight kilometer long pipeline from Moqueta to Costayaco facilities is continuing, with construction beginning in the fourth quarter of 2010 and first oil production associated with long term testing scheduled to begin in the first quarter of 2011.

Tags: Gran Tierra Energy Inc.