AMER.L Regulatory News (AMER)

13 February 2012

Amerisur Resources Plc

("Amerisur" or the "Company")

Platanillo Update

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America, announces that it has mobilised the work over rig D-6, owned and operated by Serinco Drilling SA to the Platanillo-2 location in the Platanillo Field, Colombia.

Once the unit is rigged up and tested, the Platanillo-2 well will be re-entered and worked over. The work over programme is intended to optimise the configuration of the well and will include a remedial cementation and a Drill Stem Test (DST) of the previously untested N sand formation. The N sand is an established producer in the Victor Hugo Ruales field in Ecuador, and has also been shown to be productive in recent exploratory wells in the Caguan-Putumayo basin.

Other zones may also potentially be tested under the programme. The N sand DST and recompletion programme is expected to begin in the next few days and take up to 14 days to complete. It is expected that Alea-1R will continue in normal production during these operations.

The southern access road to Drilling Platform 9 has been completed and work is well advanced on the drilling location.

John Wardle commented: "The work over of Platanillo-2 is an important opportunity for the Company to physically test the N sand and so correlate the petrophysical model to ensure that we are able to efficiently interpret the log responses in the new wells of our upcoming drilling campaign."

A presentation updated in February 2012 can be viewed on the Company website, www.amerisurresources.com

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