AMER.L Regulatory News (AMER)

2 January 2019

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

CPO -5 Operational Update

Initial flow rates of 4,530 bopd from STT at Indico-1 and immediate four-well drilling programme confirmed

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America is pleased to provide an operational update regarding the initial short term testing ("STT") at the Indico-1 well on the CPO-5 block (AMER 30%) and upcoming CPO-5 drilling programme.

Highlights

· STT at the Indico-1 well has flowed 35.9° API oil to surface from the Lower Sands ("LS3") of the Une formation at a series of choke sizes with a final flow rate of 4,530 barrels of fluid per day (gross) with a water cut of 0.33% at a choke size of 40/64" and a wellhead pressure of 241psi

· Initial analysis by the Company indicates that a 283 feet gross, 209 feet net, oil column is present in the LS3 formation at Indico-1

· Reservoir pressure data confirms an oil column throughout the LS3 reservoir, with no indication of Oil-Water-Contact ("OWC")

· Indico-1 will continue to be produced under STT while application is made to ANH to begin a Long-Term-Testing ("LTT") programme on the well

· Fully funded four-well directional drilling programme to commence immediately from the Indico pad to determine the prospectivity of the area within the LS3 play;

o Calao-1, targeting a structure alongside Indico to the southwest, towards the Aguila structure expected to spud in January 2019. On a simple structural basis, the Company estimates potential resources at Calao of between 2 and 7 mmbo

o Pavo Real-1 to follow Calao-1, targeting a similar structure adjoining Indico to the northeast. Structural evaluation by the Company estimates potential resources of 2 to 23 mmbo in this prospect

o Given the potential for combination trapping, the Company believes potential resources may be significantly higher at both Calao-1 and Pavo Real-1

o Following these wells, a further two appraisal wells will be drilled in the Indico structure from the Indico pad, with the objective of refining resources and reserves estimates

o Sol-1 is drill-ready and the Company is considering with its partner whether to drill it following the above programme or the option for a second drilling rig in the short term.

John Wardle, CEO of Amerisur said:

"The confirmation of no OWC within the drilled reservoir at Indico-1 and the initial flow rates on STT are very encouraging indeed. We are very pleased to have agreed an augmented drilling programme from the Indico pad with our partner. These wells already have all required environmental permits and hence can be drilled immediately, targeting important offsets to the Indico play. Indeed after re-location of the drilling rig we hope to initiate Calao-1 during January 2019. The initial flow data also support our view of the importance of this play, not just at Indico but also in the surrounding area, extending down to Mariposa and up to the Aguila and then Sol structures. We have no doubt that further flow improvements may be achieved during LTT, as well as improvements to surface facilities in order to optimise production from the well. We are now evaluating the resource potential within the Indico structure, with the help of the data acquired to date and of course utilising additional data that will be acquired under the continuing STT and subsequent LTT.

"These latest data from the well further indicate that we are developing an important play fairway within the LS3 unit of our large CPO-5 block, with significant upside both in the Indico accumulation, other structures to be drilled in the immediate future, as well as a long programme of exploitation within this sizeable block which is five times the size of our Platanillo block."

Indico-1

As previously reported, initial analysis by the Company indicated that a 283 feet gross, 209 feet net, oil column is present in the LS3 formation at Indico-1. The LS3 unit is a high quality sand with some shale intercalations, principally towards the base. The LS3 unit sits upon Palaeozoic basement. In the Company's initial analysis, no Oil-Water-Contact ("OWC") was detected in the wireline logs acquired in the well, hence the base of the oil column encountered at the Palaeozoic level represents a Lowest-Known-Oil for the Indico structure. The wireline formation pressure and sample data subsequently acquired in the LS3 formation confirmed an oil column throughout the reservoir, with no indication of an OWC.

Initial STT operations have been conducted on the well after running and cementing a 7 inch production liner. A 40 feet interval of the upper reservoir was perforated and a completion was installed in the well. The well initiated production in natural flow. After a short clean-up period a 24 hour pressure build up ("PBU") test was performed.

The well was subsequently flowed at a series of choke sizes, known as a Multi-Rate-Test ("MRT"), flowing 35.9° API oil to surface. The final flow rate in this MRT was 4,530 barrels of fluid per day (gross) with a water cut of 0.33% at a choke size of 40/64" and a wellhead pressure of 241psi.

Following the first MRT, the well was closed in for a further 48 hour PBU, after which downhole pressure gauges were retrieved and downhole samples captured.

The well is currently producing over a controlled choke of 28/64"at a rate of approximately 2,680 bopd with 447psi wellhead pressure, while the drilling rig is rigged down. It is envisaged that the well will continue to be produced under STT while application is made to ANH to begin a Long-Term-Testing ("LTT") programme on the well.

The LS3 sand package is the same formation which holds the 120 feet oil column discovered at Mariposa, which lies some 6.5 kilometres to the northwest of Indico-1. The Mariposa well has produced at a stable rate of approximately 3,200 barrels of oil (gross) per day in natural flow from 12 feet of perforations near the top of the 120 feet oil column for over a year, during which time it has produced over 1.2 million barrels of oil with no significant water cut, which remains at 0.05%.

CPO-5 augmented drilling programme

The scale of the reservoir thickness and oil column at Indico-1 has important implications for the prospectivity of the area within the LS3 play, as well as the degree of fill within Indico. In particular, additional structures alongside the Indico structure may now be considered to form part of the play fairway. This has led the Company and the Operator to agree an augmented forward drilling programme, with additional directional wells to be drilled immediately from the Indico-1 location. The first additional well will be Calao-1, which is targeting a structure alongside Indico to the southwest, towards the Aguila structure. On a simple structural basis, the Company estimates potential resources at Calao of between 2 and 7 mmbo. However, given the results at Indico-1, which indicate the potential for combination trapping, the Company believes potential resources may be significantly higher. The same holds for the second well to be drilled after Calao-1, named Pavo Real-1, which targets a similar structure to Calao, adjoining Indico to the northeast. Structural evaluation by the Company estimates potential resources of 2 to 23 mmbo in this prospect. It is envisaged that following these wells, a further two appraisal wells will be drilled in the Indico structure from the Indico-1 pad, with the objective of refining resources and reserves estimates. Sol-1 is also drill-ready, and the Company is considering with its partner whether that well should be drilled following the programme at Indico pad or whether a second drilling rig should be contracted to drill the well in the short term.

ENDS

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Notes to editors

About Amerisur Resources

Amerisur Resources is an experienced Colombian Operator with an extensive, strategic acreage position in the underexplored Putumayo in partnership with Occidental Petroleum ("Oxy") and a strategic acreage position in Llanos in CPO-5 with partner ONGC. Amerisur is the 100% owner and operator of the OBA pipeline, a key piece of strategic, cross-border export infrastructure delivering oil from the Putumayo in Colombia into Ecuador. Amerisur produces from two fields, Platanillo in the Putumayo which generates cash flow to fund its work programme and Mariposa-1 in the Llanos basin. Amerisur has recently announced a potentially transformational result at Indico-1, which significantly exceeded expectations - 283 feet gross, 209 feet net oil column.

Amerisur has a robust financial position with cash generation and balance sheet to fund its work programme.

Competent person: Technical information in this announcement has been reviewed by John Wardle Ph.D., the Company's Chief Executive. John Wardle has 32 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.

www.amerisurresources.com