Amerisur Resources Plc, the oil and gas explorer and developer focused on South America, provides the following update on operations in the Platanillo contract within Colombia.

In the Platanillo-2 well the 'B' limestone, 'T' sandstone and 'U' sandstone zones have been tested and all have produced crude oil.

A short test was performed in the 'B' limestone zone from 8,395ft to 8,402ft measured depth and produced crude oil at 21 to 32 degrees API with water cut of 2% to 30% at rates up to 450 barrels flowed per day (BFPD) through a 32/64' choke. Given the encouraging result, the deeper 'T' sandstone zone from 8,450ft to 8,455ft measured depth was tested. That test initially produced crude oil at up to 33.4 degrees API at rates up to 430 barrels of oil per day (BOPD) through a 22/64' choke, after which an increased water cut up to 70% was observed in the oil flow. The reasons for the increase are currently under review.

Following these tests, both intervals were temporarily suspended to allow the lower 'U' sandstone to be tested. The lower 'U' sandstone was perforated from 8,295ft to 8,298ft. The well was flowed at a controlled rate of approximately 161 BOPD through a 16/64' choke before a pressure buildup period. The crude oil has an API of approximately 32 degrees and zero water.

The partners in the Platanillo Contract have presented a 'Notice of Discovery' to the Agencia Nacional de Hidrocarburos (ANH) in relation to the hydrocarbons discovered in the 'B' limestone and the 'T' sandstone. On the basis of those discoveries, and in accordance with the terms of the Exploration and Production Contract, Ecopetrol S.A., as operator of the Platanillo Contract has applied to ANH for the approval of an 'Area of Evaluation' over the Platanillo structure.

The Company holds a 25% working interest in this block through its subsidiary, Chaco Exploracion Colombia under the Platanillo Exploration and Production Contract with the ANH. Repsol Exploracion Colombia S.A. holds 35% and Ecopetrol S.A. (40%) is the operator.

Dr. John Wardle, Amerisur's Chief Executive Officer commented, 'The discovery of hydrocarbons in two additional zones in Platanillo-2 is a great step forward for the Company, offering a significant opportunity for greater reserves within the block. There is still a great deal to understand about the Platanillo/Alea structure, and the evaluation programme will be designed to help us towards that understanding.

'The structure is far more complex than previously anticipated. In addition, the unexpectedly high productivity from the 'B' limestone has a tremendous impact on our prospects, since the limestone sections, of which there are several in the productive interval, had not previously been considered significant reservoirs, and have now indicated significant porosity and permeability. The test in the lower 'U' sandstone is a positive result, and we look forward to updating shareholders on the long term testing of both Alea-1 and Platanillo-2. '

Mr. Giles Clarke, Chairman commented,'The Board is very pleased with the further evidence of the attractiveness of the Platanillo block. We look forward to providing an update in due course.'

Tags: Amerisur Resources Plc