AMER.L Regulatory News (AMER)

5 October 2012

Amerisur Resources Plc ("Amerisur" or the "Company")

Platanillo-5 Update

·; As announced on 3 October 2012, the Platanillo-5 well encountered an interval of 99ft gross, 79ft net pay in the U sands of the Villeta formation

·; Platanillo-5 flowed 31.8°API oil with trace water at 2,472 BOPD in natural flow

·; Platanillo-5 has been placed on commercial production and is envisaged to produce at a controlled rate of approximately 1,500 BOPD initially, taking total Company controlled rate production up to approximately 3,500 BOPD

·; The Company is currently rigging down the Serinco Rig D-10 in order to move and rig up over the fourth drilling slot on Platform 9 to drill the fourth well of the current programme (Platanillo-9), deviating the well to an offset of approximately 1,550ft west of Platanillo-3

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America, is pleased to announce an update on the well Platanillo-5 in the Platanillo Field, Colombia, third of a planned eight well drilling campaign.

The Company perforated the upper 30ft of indicated net pay using a permanent completion assembly and "drop-off" tubing conveyed perforating guns. Over a flow period of 24 hours the interval produced in natural flow at a final stabilised rate of approximately 2,472 BOPD of 31.8° API oil with trace water, while choked back and with wellhead pressure of approximately 61 psi.

The well has now been placed on commercial production and will be monitored to ascertain its optimum production rate. It is envisaged that the well will be produced at a controlled rate of approximately 1,500 BOPD initially taking total Company controlled rate production up to approximately 3,500 BOPD. The Company remains confident of achieving a year end production rate of 5,000 BOPD.

The Company now plans to rig down and move the Serinco Rig D-10 and drill Platanillo-9 (so numbered due to the order in which wells were permitted with the Ministry of Mines and Energy), the fourth well of the current programme from the same location (Platform 9), deviating the well to an offset of approximately 1,550ft west of Platanillo-3.

John Wardle, Amerisur Chief Executive commented: "This is another impressive result from the Platanillo field. We continue to realise significant value in the asset, and I see significant further opportunity as we continue our development programme."

Giles Clarke, Chairman of Amerisur said: "I am very pleased with this latest result from Platanillo, which further underlines the potential we are dealing with. I would like again to congratulate Dr Wardle and our team in Bogota, who have continued to deliver success under very demanding conditions."

ENDS

Competent person: Technical information in this announcement has been reviewed by John Wardle Ph.D., the Company's Chief Executive. John Wardle has 27 years' experience in the industry, having worked for BP, Britoil, Emerald Energy and Pebercan, and is a trained drilling engineer.

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