Operational Update - CPO-5

21 November 2017

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

Operational Update - CPO-5

Production commences on second oil field in Colombia

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America, is pleased to provide an operational update on activities in the CPO-5 block, located in the Llanos basin, Colombia.

The operator of the Mariposa discovery in the CPO-5 block has informed the Company that the initial phase of the Long Term Test (LTT) of the Mariposa-1 discovery commenced on 18 November. The well was initially flowed to evacuate suspension brine and then stabilised at an initial controlled rate of 1,487 BOPD, 0.5% water cut, 40.7 degrees API and 620psi wellhead pressure. Post this clean up flow, the well has been closed in for a pressure build up test (PBU) of approximately 36 hours. The clean-up flow rate was designed simply to create the conditions for a stable PBU test, which data are required to fully evaluate the behaviour of the discovery during the LTT and does not reflect the normal productivity of the well, which is expected to be significantly higher on a sustained basis. The well is expected to be placed back onto a higher rate of commercial production in the next few days.

CPO-5 is an Exploration and Production Contract, covering 198,000 hectares and located to the south of block Llanos 34 and to the east of the Corcel fields. The block includes the evaluation area related to the Loto-1 oil discovery. Amerisur has a 30% (non-operated) working interest in the contract, ONGC Videsh Ltd holds a 70% working interest and is the Operator. The second well on the block, Indico-1, targeting an up-dip section of the Mariposa play on the Lower Sands is expected to spud in H1 2018.

The Company will provide an update on the commercial production performance of Mariposa-1 in the monthly production update in early December. The Company maintains its target 2017 exit production rate of over 7,000 BOPD.

John Wardle, Chief Executive Officer, commented:

"The commencement of production, albeit at a conservative initial controlled rate, at CPO-5 is an important milestone for Amerisur diversifying our production base from one to two oil fields and is in line with our stated strategy to increase production across our high quality portfolio of assets."

ENDS

Enquiries:

Glossary

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.

Standard

Estimates of reserves and resources contained in this announcement were prepared using the standards set by the Oil and Gas Reserves Committee of the Society of Petroleum Engineers / World Petroleum Congress Petroleum Resources Management System (2007).

Inside Information

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.

Important notice

Forward looking statements and dates referenced in this announcement, in relation to Amerisur's production, development and exploration assets, are estimates and subject to change. Oil and gas operations are subject to varying inputs that may impact timing, including, inter alia, permitting; environmental regulation; changes to regulators and regulation; third party manufacturers and service providers, social issues and the weather. The Company's estimates of timing for forward looking operations are based on the best information it has to hand at the time, however these timings may change with little or no notice to the Company. The Company will update the market as and when it becomes aware of a material change to any of the operations or timings referenced in this announcement.

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 6,100 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 including the Platanillo block, Put-8, Put-12 and Coati. Additionally, the Company holds a 100% working interest in contract Put-9, 100% of Tacacho and 100% of Terecay acquired from Talisman and Pacific. These acquisitions have now been approved by ANH. It has a diverse portfolio of longer term exploration assets.

www.amerisurresources.com