MercoPress. South Atlantic News Agency

Rockhopper has confirmed the first Contingent Oil Resource in the Falklands.

Current Share Price: 333.75p + 93.75p 4 Jun 2010  8:32am

Sam Moody, Managing Director, commented:”Our analysis of the data from the Sea Lion well suggests that there is significant potential upside on our acreage and our technical effort will now focus on integrating all of our new knowledge of the basin so we can understand and identify the best prospects for future drilling.”

”...Being a100% holder of this acreage potentially places Rockhopper in a very strong position. We are now looking forward to drilling Ernest and testing Sea Lion.The test of Sea Lion will be a key step on the road to proving commerciality. We believe that, with modern horizontal completions and water injection in sands of the quality encountered, recovery factors significantly above the 15% assumed in the P90 case could be achieved. Furthermore, our recently updated economic model indicates that a stand alone field of 60mmbbls recoverable could be commercial at oil prices down to US$50 per barrel.”

Sea Lion Exploration Well – 14/10-2 Oil Discovery – Technical Update

Rockhopper Exploration, the North Falkland Basin oil and gas exploration company, is pleased to provide the following update regarding analysis of the results of the Sea Lion 14/10-2 well oil discovery recently completed in the North Falkland Basin:

Highlights:

• Samples analysed in a dedicated laboratory confirmed as medium gravity crude oil –ranging from 26.4° to 29.2° API
• Every sand in the well beneath regional seal charged with oil
• RPS Energy Best Estimate recoverable upgraded from 170mmbbls to 242mmbbls recoverable with significant upside potential
• Board believes new play fairway opened
• 217 metres gross oil column, 53 metres net pay
• The Company intends to test the well at the earliest opportunity during the current campaign

Results of data analysis

Well 14/10-2 on the Sea Lion prospect (“Sea Lion” or “the Sea Lion well”) was drilled to a depth of 2,744 metres during April and May 2010. Following completion of final logging, the well was suspended for future testing. The Company intends to test the well at the earliest opportunity during the current campaign and test equipment is currently being mobilised.

The well penetrated what the Company believes is a regional seal between 2,250 metres and 2,374 metres subsea. Based on log analysis, well site evaluation of shows and samples, sidewall cores and wireline formation testing, it appears that all sands encountered beneath this regional seal at the Sea Lion location are charged with oil and no oil water contacts were encountered.

The top oil sand in the Sea Lion well was encountered at 2,374 metres subsea, and the base of the lowest oil sand (“oil down to”) level was encountered at 2,591 metres subsea. The total vertical oil column is 217 metres (712 feet), with total net pay of 53 metres in seven identified pay zones, the thickest of which is approximately 30 metres gross.

Pressure data suggest the possibility of two separate oil columns, although this will have to be confirmed by a full well test. The main Sea Lion fan has a net pay interval of 34.5 metres. Additional underlying sands have net pay totalling approximately 18 metres. Approximately 16m of this lower pay appears to relate to a Sea Lion lower fan, which had been previously recognised, but not included as a primary prospect. A further 2 metres of deeper pay has also been encountered.
 The oil down to level of 2,591 metres subsea is 116 metres beneath the lowest mapped point of the Sea Lion fan. The entire Sea Lion fan has an aerial extent of over 45 sq km and there are strong seismic indications of thicker reservoir packages elsewhere in the fan. The oil down to level is significantly lower than the lowest pointofthSeaLion main fan.

Full report available on the Company’s web site – www.rockhopperexploration.co.uk