AMER.L Regulatory News (AMER)

20 April 2017

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

Operations Update

Platanillo-22 Flow tested ahead of pre-drill expectations - Deeper oil-water contact found - Reserves upgrade expected

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America, is pleased to announce an update on operations in the Platanillo field in Colombia.

· Platanillo-22 has been tested at 613 barrels of oil per day (BOPD) materially ahead of pre-drill expectations 

· Well has been placed on commercial production and produced oil is being trucked to the southern pads for export via the OBA system

· Observed results suggest that the oil accumulation at Pad 2N has a separate closure from Pad 3N and the greater Platanillo field - importantly, the oil water contact ("OWC") is deeper than the main field

· As a result, provisional re-mapping indicates the potential for up to 7.82MMBO of recoverable reserves within the Pad 2N structure, previous estimate of 1.4MMBO

· Serinco D-10 rig expected to spud Platanillo-21 from Pad 2N in next few days

Platanillo-22 has been tested at 613 barrels of oil per day (BOPD) with 0.22% water cut from a 14ft perforated interval in the lower U sand using a hydraulic pump lifting system. The tested oil quality is slightly better than the main Platanillo field at 31.5 degrees API. The pre-drill production estimate for this well was in the range of 300 to 400 BOPD. The well has been placed on commercial production and produced oil is being trucked to the southern pads for export via the OBA system.

The structure drilled by Platanillo-22, located at Pad 2N, approximately 3.38 km north of Pad 3N was previously undrilled but was believed, on the basis of seismic data to be connected to Pad 3N. Drilling and logging data indicate that the structure is separate and the nature of its closure may offer further reserves upside than previously envisaged on the basis of 3D seismic.

The reservoir units in the Cretaceous Villeta formation were encountered slightly deeper than prognosed. However, the Oil Water Contact (OWC) within the reservoirs was encountered significantly deeper than expected, being 37ft deeper in the Upper U and 23ft deeper in the Lower U formation. No OWC was observed in the N sand. The T sand did not indicate pay in this well. The greater effective oil column in the U sands is likely to increase certified reserves in the field.

The observed results suggest that the oil accumulation at Pad 2N has a separate closure compared to Pad 3N and the greater Platanillo field. This indicates the presence of a permeability barrier between those pads, which may be formed either by a sub-seismic fault or a stratigraphic feature which allowed the Pad 2N structure to be filled to a greater extent than the remainder of the field. Since the reception of these data the Company has been closely evaluating the 3D seismic cube and the anomaly processing and has identified certain subtle features within the basement and overlying formations which may be the cause of that barrier. Provisional re-mapping has been performed and the Company estimates, using volumetric calculations, the potential for up to 7.82 million barrels of oil (MMBO) of recoverable reserves within the Pad 2N structure, as opposed to the previous estimate of approximately 1.4MMBO. Further testing of Platanillo-22, and drilling of further wells are required to define the actual increase in potential reserves. Once these activities are performed Amerisur will commission an independent reserves report to SPE standards.

The Company has now moved the drilling rig Serinco D-10 over the adjacent drilling cellar on Pad 2N, and expects to spud Platanillo-21 in the next few days. Platanillo-21 is a short deviation directional well aimed at the crest of the mapped structure, with a drilling offset of 250ft and a total planned measured depth of 8,485ft. Given the important results from Platanillo-22, the Company plans to log this well with both Logging While Drilling and Wireline techniques, and additionally to acquire core data through the entire Villeta sequence, i.e. from top N Sand to the igneous basement. These data will be important in terms of enhancing understanding at Pad 2N and in our nearby prospects and adjoining blocks.

On the CPO-5 block, well Mariposa-1 is currently at a casing point at 10,575ft.

John Wardle, Chief Executive Officer of Amerisur, commented:

"Our production expectations of Platanillo-22 have been exceeded by the testing results from the perforated interval, with further pay available in the well to exploit in the future. The important discovery that the OWC is deeper than the main field is very good news indeed, and we look forward to confirming the magnitude of the increase in reserves this creates as operations continue. This result will lead us to drill further wells from Pad 2N than previously envisaged, and we are currently planning the drilling of a third well from Pad 2N."

"I look forward to updating the market on the progress of Platanillo-21 and the continuing production from Platanillo-22."

Giles Clarke, Chairman of Amerisur said:

"The confirmation of the production potential of Platanillo-22 and the existence of a deeper OWC is an exciting development which adds further value to Amerisur shareholders through increasing our reserves and is an important step towards our production targets. Our continuing drilling success is a tribute to the quality of the Platanillo Field but also gives me great confidence in our ability to add further reserves from similar structures in our strategically located portfolio."

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. 

Glossary:

"Degrees API" - is a measure of the density of a hydrocarbon fluid. 10 degrees API is a hydrocarbon of equivalent density to fresh water. The higher the API in degrees, the less dense the hydrocarbon fluid. The API degree is calculated from the specific gravity of the hydrocarbon fluid via the following formula:

API Gravity (in degrees) = (141.5/Specific Gravity of fluid) - 131.5

ENDS

Enquiries:

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 4,200 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.

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