Chaco Announces Spudding of Sayona-1

Chaco Resources Plc said that the Sayona-1 well, the second well on the Primavera block in the Llanos Basin in Colombia, has begun drilling. The well, which is operated by Gran Tierra Energy, is planned to drill to approximately 3,800 feet, and is expected to take approximately two weeks. Chaco Resources has a 55% interest in the well.

The exploration targets are the high-quality sands of the Carbonera formation.

The current exploration phase in the Primavera block terminates in May 2007. The completion of the Sayona-1 well will constitute the completion of our exploration commitment for phase one of the work program on the block.