Santana & Guayuyaco

• Participation - Gran Tierra (Operator) 35%, Ecopetrol 65%
• Area - 1,119 acres (gross); 392 acres (net)

The Santana & Guayuyaco Contract area includes 4 producing fields - Linda, Mary, Miraflor and Toroyaco - and 15 wells. Activities are governed by terms of an Association Contract with Ecopetrol.. The Block has been producing since 1991; a total of 21.9 million barrels (gross) have been produced to Sept 30, 2009.

Chaza

• Participation - Gran Tierra (Operator) 100%
• Area - 80,242 acres

The Chaza Block is governed by terms of an Exploration and Exploitation Contract with the government agency ANH, reflecting re-vamped and improved fiscal terms. The Chaza Contract was signed June 2005 and defines a 6 year exploration period and 24 year production period. The Costayaco field is the largest discovery in the Putumayo Basin since the 1960's. Production is from the Caballos and T Sandstone. Cum production to September 2009 is 5.4 mmboe.

Mecaya

• Participation - Gran Tierra (Operator) 15%, MCP 55%, Expet 30%
• Area - 74,128 acres (gross); 11,119 acres (net)

The Mecaya Exploration & Exploitation contract was signed June 2006.

Azar

• Participation - Gran Tierra (Operator) 40%, Lewis Energy 40%, Geoadinpro 20%
• Area - 51,639 acres (gross); 20,656 acres (net)