30 May 2017

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

 Mariposa-1 Update CPO-5 Block

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America, is pleased to provide the following update on drilling activities in the CPO-5 contract in Colombia.

The 7" production liner was successfully run and cemented in Mariposa-1, the exploration well drilled in the north-western part of the CPO-5 block. An interval of 12 feet at the top of the 120 feet of net pay logged in the L3 sandstone was perforated in order to perform a short-term test with a drill-stem-test temporary string.

The well was tested in natural flow over a variety of choke sizes, together with appropriate closed-in pressure build up periods to ascertain reservoir parameters. The natural controlled flow rate recorded was approximately 4,601 barrels of oil per day of 40.8 degree API oil with a water cut of 0.35% and 348psi flowing wellhead pressure over a 40/64" choke. 

The well has now been closed in pending interpretation of the short term test data. 

John Wardle, Chief Executive Officer, commented:

"This is a very promising initial short term test of Mariposa-1, the high wellhead pressure during the final flow period indicates strong further production potential. The Company is now considering the results of the test together with our partner to confirm plans for a potential long term test, the potential for further appraisal wells on this structure and the potential to declare the well a discovery under the terms of the CPO-5 Exploration and Production Contract held with the Agencia Nacional de Hidrocarburos."

Competent person: Technical information in this announcement has been reviewed by John Wardle Ph.D., the Company's Chief Executive. John Wardle has 31 years' experience in the industry, having worked for BP, Britoil, Emerald Energy and Pebercan, and is a trained drilling engineer.

This announcement contains inside information as defined in EU Regulation No. 596/2014 and is in accordance with the Company's obligations under Article 17 of that Regulation.

ENDS

Enquiries:

Nick Harrison, CFO                            Tel: +44 (0)330 333 8246

Amerisur Resources                         

Billy Clegg/Georgia Edmonds             Tel: +44 (0)203 757 4980

Camarco

Callum Stewart/Ashton Clanfield        Tel: +44 (0)20 7710 7600

Stifel Nicolaus Europe Limited

Chris Sim/George Price                     Tel: +44 (0)207 597 4000

Investec

Darrell Uden/Marcus Jackson            Tel: +44 (0)207 653 4000

RBC Capital Markets

 Notes to editors

Amerisur Resources is an independent full-cycle oil and gas company focused on South America, with assets in Colombia and Paraguay and production from the Platanillo field in southern Colombia. In 2016 Amerisur successfully built and is 100% owner of the strategic OBA oil transfer line into Ecuador.

In Colombia, the Company is operator and has a 100% working interest in the Platanillo block which includes the Platanillo field, which is currently producing circa 5,200 BOPD.  The Company has a strong position in the Putumayo basin and has a cluster of near term activity assets around the OBA export line.  It has a diverse portfolio of longer term exploration assets.

As a reminder, Amerisur acquired its 30% interest in the CPO-5 block as part of the acquisition of Petro Dorado South America SA (PDSA), a subsidiary of Petro Dorado Energy Ltd (PDEL).  In that contract ONGC Videsh is the Operator and holds a working interest of 70%.

www.amerisurresources.com

This information is provided by RNS

The company news service from the London Stock Exchange

 END