Amerisur Provides Operations Update

Amerisur Resources, the oil and gas explorer and developer focused on South America stated at the recent AGM that an announcement would be made once 3D acquisition was completed in the Fenix block. As a consequence of good progress, Amerisur is pleased to provide the following trading update.


The civil works are complete for Platanillo-1 and the operator Ecopetrol has authorised the mobilisation of the Pride-17 drilling rig to the well location. The rig mobilisation is scheduled to take approximately three weeks and Amerisur expects the well to spud during the first half of September 2007, followed by testing and results in October 2007.

The Platanillo-2 well will be drilled 'back-to-back' with Platanillo-1, using the same rig. The location of the well will depend on the results obtained in Platanillo-1. Subject to the possibility of additional civil works, it is expected Platanillo-2 will be spudded during October 2007.

Amerisur expects the workover rig Pride-6 will be mobilised to the Alea-1 location during the first half of September 2007. Alea is an existing discovery, made in 1988, when the well flowed at rates of up to 533 barrels per day. It is anticipated that re-entry operations will commence during the second half of September, followed by testing and results in October 2007.

Negotiations continue with respect to the acquisition of an increased working interest in the Platanillo contract. Any such change in participation would be subject to approval by ANH.

Current working interests in this block are:

Ecopetrol S.A. (Operator)                            40%
Repsol YPF                                           35%
Amerisur Resources Plc                               25%


A 103 km^2 3-D seismic survey on the Fenix block in the Middle Magdalena basin has been completed, 20 days ahead of schedule. The program, which covered a number of leads identified by analysis of 2D seismic data, employed a workforce of over 500 people, and included the detonation of 2,880 shots and the laying of 270km of geophone lines.

The acquired data will be processed during September 2007 ahead of interpretation work. Amerisur expects interpretation to be completed and potential drilling locations identified during the course of Q1 2008.

Working interests in the block (after approval by ANH and earn-in commitments) will be:

Fenix Oil and Gas SA (Operator)                            35.00%
Amerisur Resources PLC                                     48.75%
Colombian Associates                                       16.25%


Amerisur is currently reviewing its options with regard to a 2D seismic survey in Paraguay, together with the application of other surface geophysical & geochemical techniques. It is expected the 2008 work programme in Paraguay will be confirmed during November 2007.

Dr John Wardle, Amerisur's Chief Executive Officer commented:

"Amerisur's drilling and re-entry programme at Platanillo is progressing according to schedule with results expected from all three wells over the coming months. Platanillo is an advanced project with near term production potential and we look forward to the commencement of rig operations next month. In addition, following successful completion of a 3D seismic survey at Fenix, we believe that modern interpretation techniques materially enhance the likelihood of drilling success on this block."