Deep Kinsale

22nd May 2013

Fastnet Oil & Gas plc

Operational Update, Scoping Independent Resource Estimates and Forward Program for Deep Kinsale

Fastnet Oil & Gas plc ("Fastnet" or the "Company") (AIM: FAST, ESM: FOI) the E&P company focused on near term exploration acreage in Africa and the Celtic Sea, is pleased to provide an operational update, scoping independent resource estimates and an outline of the forward program for the Deep Kinsale farm in area ("Deep Kinsale").

Highlights

§ Acquisition of 500 sq. km. of 3D seismic recently completed over Deep Kinsale and significantly under budget

§ Aggregated Unrisked Gross P50 Best Case Prospective resources for Deep Kinsale of 2.365 billion barrels of oil in-place

§ Risked Potential Resources Estimates of oil in-place for Deep Kinsale in the range of 134 mm barrels to 691 mm barrels, reflecting the early stages of evaluation and analysis

§ Independent Pre-drill Pilot Development Study for Deep Kinsale being undertaken based on conceptual design work for the Seven Heads (now "Barryroe") Oil Field first carried out in 2002 for Island Petroleum Developments Limited

OPERATIONAL UPDATE

The SR/V Vantage vessel ("SR/V Vantage"), under contract to Fastnet from CGG, completed the acquisition of 500 sq. km. of 3D seismic data over Deep Kinsale significantly ahead of schedule and under budget. The operationally complex seismic undershoot of the Kinsale Alpha and Bravo platforms was achieved without incident using the SR/V Vantage and the SR/V Angler vessel, a second seismic vessel contracted to Fastnet from CGG solely for the undershoot operations.

SCOPING INDEPENDENT RESOURCE ESTIMATES

An independent assessment of the Company's potential prospective resources for the Deep Kinsale has been completed by SLR Consulting. Fastnet is the technical operator for Deep Kinsale and, as announced on 21 February 2013, can earn 60% equity (reducing to a minimum of 40% should PSE Kinsale Energy exercise certain back-in rights linked to cumulative produced BOE resources ) by drilling a well before 30 November 2015.

The independent assessment was carried out in accordance with generally accepted international standards. The following tables have been prepared by Fastnet for the convenience of readers to summarise unrisked prospective in-place hydrocarbon resources in Deep Kinsale and the associated geological chance of success ("GCoS").

UNRISKED GROSS PROSPECTIVE IN-PLACE RESOURCES (DEEP KINSALE)

AS AT 22nd MAY 2013

Best Estimate unrisked in-place oil volumes for the four reservoir units taken together are 2.365 billion barrels or 335.3 million barrels when considering the geological probability of success.

The independent assessment confirms that oil-bearing sands (based on well log analysis) encountered in the Middle and Lower Wealden wells drilled by Marathon in the early 1970's occur in the same geological structure that hosts the shallow producing gas sands in the Greensand and Upper Wealden .in the Kinsale gas field. The Deep Kinsale structure covers an area of up to 162 sq. km.

FORWARD PROGRAM

The successful completion of the 3D seismic acquisition is the first step in the process of increasing the GCoS for the Deep Kinsale structure. Once the 3D seismic has been processed and interpreted, the data generated will provide new information to reduce the range in the in-place resources estimates; identify any potential for structural compartmentalization by faulting; and, by using seismic attributes analysis, define potential reservoir "sweet spots". This information will be combined with a new analysis of the active petroleum systems around and under the Kinsale Head gas field focusing on hydrocarbon charging mechanisms and the potential for re-migration during Tertiary basin uplift. This will help to identify the target area for the farm-in well which will be designed to meet the requirements of the option agreement entered into with PSE Kinsale Energy Limited based off the results of the independent pilot development study that is being commissioned by Fastnet.

A key pre-drill element of the forward work program is an independent pilot development study to address and manage development risk associated with the particular geological characteristics of the Basal Wealden Oil Sand. The key objective of the geological and geophysical work outlined above is to high grade an area for drilling in the Deep Kinsale structure that has the lowest risk of finding minimum oil in-place threshold resources of 100 mm barrels. In 2002 some of the Fastnet management team, whilst with Island Petroleum Developments Limited, commissioned independent pilot development studies for the Seven Heads oil field (now "Barryroe") based on relatively modest in-place resource estimates. Subsequent reservoir engineering studies indicated that this was a break-even economic option at the time when oil price was around USD 40 per barrel. Fastnet's experienced management team maintains that a phased development program is the best way to manage reservoir risk for the Basal Wealden Oil Sand.

John Craven, a founder shareholder of Fastnet, commented:

"I am delighted that Fastnet has progressed rapidly to acquire the 3D seismic data over Deep Kinsale, which also included undershooting the two Kinsale production platforms. Deep Kinsale is a large anticlinal structure, which has the potential to contain a significant oil accumulation directly beneath the producing Kinsale gas field and the two platforms, in the Celtic Sea. This new 3D seismic is a key de risking component necessary for the planning of an optimal drilling campaign".

Commenting, Paul Griffiths, MD of Fastnet, said:

"We are delighted to have operated the first seismic undershoot ever performed offshore Ireland without incident and to have successfully completed the 3D seismic program ahead of schedule and under budget. SLR Consulting's independent assessment of potential in-place oil resources for Deep Kinsale confirms the scale of the opportunity for our shareholders. While there is always inherent risk associated with early stage exploration, we believe that our successful efforts to de-risk the assets will allow us to achieve our objectives of creating significant value through initial drilling and securing a strategic farm-out transaction.. In line with this approach we are working to ensure that a potential farm-in well, combined with high quality 3D seismic definition of structure and reservoir "sweet spots", delivers the results necessary for an economically viable pilot development at today's oil prices. We are fortunate to benefit from a wealth of relevant experience and expertise within our management team to execute this task successfully."

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Notes to editors

Fastnet Oil & Gas plc is an independent oil and gas exploration company that focuses on identifying early stage exploration and appraisal opportunities in Offshore Ireland and Africa. It is quoted on the AIM market of the London Stock Exchange and the Enterprise Securities Market ("ESM") of the Irish Stock Exchange. Fastnet's aim is to assemble a portfolio of high impact conventional oil and gas assets that will deliver sustainable growth and value for the Company. Its immediate focus is on implementing its Offshore Ireland and Africa strategies where it has been awarded four offshore licensing options in the Celtic Sea (Molly Malone Basin, Shanagarry, 49/13 and Mizzen Basin) and acquired a material interest in the highly prospective Foum Assaka permit Offshore Morocco. In addition, Fastnet will continue to pursue new conventional oil and gas opportunities in Africa where the Directors and Advisory Board also have extensive knowledge, contacts and experience of creating value.

Notes:

1. Prospects are features that are sufficiently well defined, on the basis of geological and geophysical data, to the point where they are considered viable drilling targets.

2. "Gross Unrisked Prospective Resources" are 100% of the volumes estimated to be recoverable from a field.

3. The GCoS reported here represents an indicative estimate of the probability that drilling this Prospect would result in a discovery, which would warrant the re-classification of that volume as a "Contingent Resource". The GCoS value for Contingent Resource is, by definition, unity. These GCoS values have not been arithmetically applied to the designated volumes within this assessment. Thus the volumes are "Unrisked".

4. It is inappropriate to aggregate Prospective Resources without due consideration of the different levels of risk associated with each Prospect and the potential dependencies between them.

5. The above table represents the expected outcomes for an oil discovery based on the nearest analogue being the undeveloped Barryroe oil field.