Rockhopper Exploration, the North Falkland Basin oil and gas exploration company, provides the following update on the interpretation of the fast track seismic data over acreage on licences PL032 and PL033:

• Initial interpretation of fast track new seismic data in PL032 and PL033 completed • Seismic shows Sea Lion Main Complex (SLMC) to extend to the south and new high case area to extend over 90km2 • Two new fan prospects identified within new seismic, Casper and Kermit • Management interpretation for SLMC potential size: Low Case 608 Mmbbls STOIIP Mid Case 1,086 Mmbbls STOIIP High Case 1,279 Mmbbls STOIIP

Volumes listed above are within Rockhopper’s 100% owned acreage. Not included in the high case listed above, based upon the current interpretation, the Company believes that up to approximately 10% additional volume could be contained within licence PL004, in which Rockhopper has a non-operated 7.5% working interest.

During 2011 the Company acquired a total of over 4000km2 of 3D seismic data in conjunction with other operators in the area. Data over the southern portion of licences PL032 and PL033 has been fast track processed and an initial interpretation has now been completed. This initial interpretation, combined with well data from 14/10-2, 14/10-3, 14/10-4, 14/10-5 and 14/10-6, indicates that the SLMC comprises two fan lobes sourced from the same main feeder channel just to the east of the 14/10-5 and 14/10-2 wells.

The two lobes, represented as sand packages within the wells, are identified as the SL20 and SL10 units, and, from the formation pressure data acquired in the wells, are shown to be in pressure communication. The two packages together comprise the SLMC and are interpreted to comprise of mass flow turbidite sand sequences prograding from the sand input point to the east and extending beyond the southern boundary of licence PL032 into licence PL004, where Rockhopper has a non-operated 7.5% working interest.

The Company believes that recovery rates of 30% to 40% could be achievable using industry standard production techniques including water injection, artificial lift, deviated or horizontal wells and /or other enhanced oil recovery techniques.

Should a recovery factor of 30% be achieved, based upon the Company’s mid case area, the SLMC would contain approximately 325mmbbls recoverable oil. Should a recovery factor of 40% be achieved, the mid case number would increase to 434mmbbls recoverable oil.

The fast track seismic interpretation has enabled the identification of two new feeders into the basin and the mapping of two new prospects, Casper and Kermit. Both of these comprise similar fan systems fed from eastern basin margin feeder channels and exhibit similar seismic character to the SLMC. Casper is stratigraphically shallower than the SLMC while Kermit is stratigraphically deeper than the SLMC.

Following well 14/10-6 the Company believes that the B15 sand, which forms part of the lower fan complex, has the potential to contain up to 161 mmbbls STOIIP on a high case basis. Formation pressure testing indicates that B15 is also in communication with the SLMC.

Tags: Rockhopper Exploration plc