Amerisur Resources : Reserves Update

20 September 2019

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

Reserves Update

Amerisur Resources Plc (LSE: AMER), the oil and gas producer and explorer focused onshore Colombia, provides the following reserves update for its production assets in Colombia as at 31 July 2019 covering the Company's Indico and Mariposa fields (together CPO-5) and Platanillo field.

Reserves Update Summary

· The independent reserves report was completed by McDaniel and Associates Consultants Ltd ('McDaniel'), a leading independent oil and gas industry expert

· Undertaken as part of the ongoing Formal Sales Process

· Total Company reserves estimated to be 15.04 MMBO 1P, 21.80 MMBO 2P and 31.13 MMBO 3P (as at 31 July 2019), with 1.2 mmboe produced in 2019 to end July

· CPO-5 2P reserves estimated to be 9.5 MMBO (as at 31 July 2019)

o Increased to reflect production history that indicates larger oil in place and higher recovery factors

o Further drilling activity on CPO-5 is scheduled for H2 2019, commencing with the Indico-2 appraisal well. The 30-day well is planned to increase production and reserves with the potential to extend the Oil Water Contact

o Production started from the Indico discovery in the CPO-5 block in January

o 2019 Working Interest Production to end July of 0.43 MMBO

· Platanillo 2P reserves estimated to be 12.3 MMBO (as at 31 July 2019)

o Lower to reflect a more conservative approach to economics late in the life of the field

o Working Interest Production to end July of 0.78 MMBO

Strategic Review and Formal Sale Process ('FSP')

· Multiple parties participating in the FSP following the signing of confidentiality agreements

· Management presentations with interested parties currently being held in Bogotá

John Wardle, CEO of Amerisur Resources said:

'We are pleased to complete the update to our reserves and transition the review of our full portfolio to McDaniel and Associates. We have had feedback from participants in the FSP that they value the new independent assessment from McDaniel. The report highlights the near-term value of the Company's CPO-5 asset.'

Extraction of key Reserves and Resources data contained within McDaniel's report

Table 1 - A summary of the Reserves attributed to Amerisur's assets as at end July 2019

	Reserves Oil & Liquids Gross (MMBO)			Reserves Oil & Liquids Net Working Interest (MMBO)			Operator
Blocks (Amerisur Working Interest)	Proved (1P)	Proved & Probable (2P)	Proved, Probable & Possible (3P)	Proved (1P)	Proved & Probable (2P)	Proved, Probable & Possible (3P)
Platanillo (100%)	8.60	12.30	16.23	8.60	12.30	16.23	Amerisur Resources
CPO-5 (30%)	21.48	31.67	49.68	6.44	9.50	14.90	ONGC Videsh
Total	30.08	43.97	65.91	15.04	21.80	31.13

McDaniel's independent reserves report undertaken using standards set by the Oil and Gas Reserves Committee of the Society of Petroleum Engineers, certified 1P (Proven) working interest field reserves were 15.04 MMBO, 2P (Proven and Probable) working interest reserves were 21.80 MMBO and 3P (Proven, Probable and Possible) working interest reserves were 31.13 MMBO.

Standard: These assessments are made in accordance with the standard defined in the SPE/WPC Petroleum Resources Management System (2007).

Technical information in this announcement has been reviewed by John Wardle Ph.D., the Company's Chief Executive. John Wardle has over 30 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.

Glossary

'BOPD'	barrel of oil per day
'MMBO'	million barrels of oil equivalent
'Proved Reserves'	Proved Reserves (1P) are those quantities of petroleum that, by analysis of geoscience and engineering data, can be estimated with reasonable certainty to be commercially recoverable from known reservoirs and under defined technical and economic conditions. If deterministic methods are used, the term reasonable certainty is intended to express a high degree of confidence that the quantities will be recovered. If probabilistic methods are used, there should be at least a 90 percent probability that the quantities actually recovered will equal or exceed the estimate.
'Probable Reserves'	Probable Reserves are those additional Reserves which analysis of geoscience and engineering data indicate are less likely to be recovered than Proved Reserves but more certain to be recovered than Possible Reserves. It is equally likely that actual remaining quantities recovered will be greater than or less than the sum of the estimated Proved + Probable Reserves (2P). In this context, when probabilistic methods are used, there should be at least a 50 percent probability that the actual quantities recovered will equal or exceed the 2P estimate.
'Possible Reserves'	Possible Reserves are those additional Reserves which analysis of geoscience and engineering data suggest are less likely to be recoverable than Probable Reserves. The total quantities ultimately recovered from the project have a low probability to exceed the sum of Proved + Probable + Possible (3P) Reserves, which is equivalent to the high estimate scenario. In this context, when probabilistic methods are used, there should be at least a 10 percent probability that the actual quantities recovered will equal or exceed the 3P estimate.
'Reserves'	Reserves are those quantities of petroleum anticipated to be commercially recoverable by application of development projects to known accumulations from a given date forward under defined conditions. Reserves must further satisfy four criteria: they must be discovered, recoverable, commercial, and remaining (as of the evaluation date) based on the development project(s) applied. Reserves are further categorized in accordance with the level of certainty associated with the estimates and may be sub-classified based on project maturity and/or characterized by development and production status.
'WI'	working interest

Ends

Enquiries:

Nathan Piper, Head of Business Development and Comms Amerisur Resources	Tel: [phone]
Billy Clegg/Kimberley Taylor	Tel: [phone]
Camarco
Callum Stewart/Jason Grossman/Nicholas Rhodes/Ashton Clanfield Stifel Nicolaus Europe Limited	Tel: [phone]
Jeremy Low/Tom Hughes/Tom Rider/Neil Elliot BMO Capital Markets Chris Sim/Tejas Padalkar	Tel: [phone] Tel: [phone]
Investec
Paul Shackleton/Dan Gee-Summons Arden Partners Plc	Tel: [phone]

About Amerisur Resources

Amerisur Resources is an experienced Colombian Operator with an extensive, strategic acreage position in the underexplored Putumayo Basin with Occidental Petroleum ('Occidental') and a prospective Block CPO-5 in the Llanos Basin with 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 three fields, Platanillo, Mariposa and Indico that together generate cash flow to fund its work programme.

www.amerisurresources.com

About Stifel Nicolaus Europe Limited

Stifel Nicolaus Europe Limited ('Stifel'), which is authorised and regulated in the United Kingdom by the Financial Conduct Authority, is acting exclusively for Amerisur and no one else in connection with the FSP referred to in this announcement and will not be responsible to anyone other than Amerisur for providing the protections offered to clients of Stifel nor for providing advice in relation to the FSP or any other matters referred to in this announcement.

About BMO Capital Markets

BMO Capital Markets Limited ('BMO Capital Markets'), which is authorised and regulated in the United Kingdom by the Financial Conduct Authority, is acting exclusively for Amerisur and no one else in connection with the FSP referred to in this announcement and will not be responsible to anyone other than Amerisur for providing the protections offered to clients of BMO Capital Markets Limited nor for providing advice in relation to the FSP or any other matters referred to in this announcement.

About Arden Partners

Arden Partners plc ('Arden'), which is authorised and regulated in the United Kingdom by the Financial Conduct Authority, is acting exclusively for Amerisur and no one else in connection with the FSP referred to in this announcement and will not be responsible to anyone other than Amerisur for providing the protections offered to clients of Arden nor for providing advice in relation to the FSP or any other matters referred to in this announcement.

About Investec

Investec Bank plc ('Investec'), which is authorised by the Prudential Regulatory Authority and is regulated in the United Kingdom by the FCA and the Prudential Regulatory Authority, is acting exclusively for Amerisur and no one else in connection with the FSP referred to in this announcement and will not be responsible to anyone other than Amerisur for providing the protections offered to clients of Investec nor for providing advice in relation to the FSP or any other matters referred to in this announcement.

Disclosure requirements of the Takeover Code

Under Rule 8.3(a) of the Takeover Code, any person who is interested in 1 per cent. or more of any class of relevant securities of an offeree company or of any securities exchange offeror (being any offeror other than an offeror in respect of which it has been announced that its offer is, or is likely to be, solely in cash) must make an Opening Position Disclosure following the commencement of the offer period and, if later, following the announcement in which any securities exchange offeror is first identified. An Opening Position Disclosure must contain details of the person's interests and short positions in, and rights to subscribe for, any relevant securities of each of (i) the offeree company and (ii) any securities exchange offeror(s). An Opening Position Disclosure by a person to whom Rule 8.3(a) applies must be made by no later than 3.30 pm (London time) on the 10th Business Day following the commencement of the offer period and, if appropriate, by no later than 3.30 pm (London time) on the 10th Business Day following the announcement in which any securities exchange offeror is first identified. Relevant persons who deal in the relevant securities of the offeree company or of a securities exchange offeror prior to the deadline for making an Opening Position Disclosure must instead make a Dealing Disclosure.

Under Rule 8.3(b) of the Takeover Code, any person who is, or becomes, interested in 1 per cent. or more of any class of relevant securities of the offeree company or of any securities exchange offeror must make a Dealing Disclosure if the person deals in any relevant securities of the offeree company or of any securities exchange offeror. A Dealing Disclosure must contain details of the dealing concerned and of the person's interests and short positions in, and rights to subscribe for, any relevant securities of each of (i) the offeree company and (ii) any securities exchange offeror(s), save to the extent that these details have previously been disclosed under Rule 8. A Dealing Disclosure by a person to whom Rule 8.3(b) applies must be made by no later than 3.30 pm (London time) on the Business Day following the date of the relevant dealing.

If two or more persons act together pursuant to an agreement or understanding, whether formal or informal, to acquire or control an interest in relevant securities of an offeree company or a securities exchange offeror, they will be deemed to be a single person for the purpose of Rule 8.3.

Opening Position Disclosures must also be made by the offeree company and by any offeror and Dealing Disclosures must also be made by the offeree company, by any offeror and by any persons acting in concert with any of them (see Rules 8.1, 8.2 and 8.4).

Details of the offeree and offeror companies in respect of whose relevant securities Opening Position Disclosures and Dealing Disclosures must be made can be found in the Disclosure Table on the Panel's website at www.thetakeoverpanel.org.uk, including details of the number of relevant securities in issue, when the offer period commenced and when any offeror was first identified. You should contact the Panel's Market Surveillance Unit on [phone] if you are in any doubt as to whether you are required to make an Opening Position Disclosure or a Dealing Disclosure.

Publication on website and hard copies

A copy of this announcement and the documents required to be published by Rule 26 of the Takeover Code will be available, subject to certain restrictions relating to persons resident in Restricted Jurisdictions, on Amerisur's website at http://www.amerisurresources.comby no later than 12 noon on the Business Day following the date of this announcement. For the avoidance of doubt, the content of the website is not incorporated into and does not form part of this announcement.