14/10-4 Appraisal Well Update

RNS Number : 2716D

Rockhopper Exploration plc

21 March 2011

 

Embargoed: 0700hrs, 21 March 2011

Rockhopper Exploration plc

("Rockhopper" or the "Company")

14/10-4 Appraisal well update

Rockhopper Exploration, the North Falkland Basin oil and gas exploration company, is pleased to provide the following update on the 14/10-4 appraisal well.

• Significant reservoir package and hydrocarbon column encountered
• 33m (108 ft) net pay in good quality reservoir with 20% average porosity
• Top reservoir encountered 66m (216ft) downdip from 14/10-2
• Oil Water Contact at 2477m true vertical depth subsea (2503m measured depth) in main fan indicates to the Company that the southern main sea lion fan is full to spill
• Company believes P90 increased significantly
• Company has significantly increased confidence in commerciality
• Oil indicated as medium grade similar to 14/10-2
• Downhole mini Drill Stem Test successfully flowed oil into the well and indicates better potential flow rates and producibility than at 14/10-2

14/10-4 was drilled 2.3 km WNW of the 14/10-2 discovery well to a total depth of 2801 metres (drilled depth) within the Sea Lion discovery area, and was the first appraisal well on the Sea Lion feature, designed to investigate reservoir presence and oil column at a downdip location.

The well has been successful, proving a thick, high quality reservoir package, a substantial oil column and recognition of the first oil-water contact in the licence to date. The geological prognosis came in very close to prediction.

The top Sea Lion reservoir sands were encountered 66m (216 ft) downdip from the 14/10-2 discovery well. A total reservoir package of 107m (351 ft) comprising four main sands was encountered with a net to gross of 76%. Average porosity is 20% and permeability is over 100 millidarcies.

30m of net pay has been encountered in the upper of the four sands, representing the main Sea Lion southern fan.  The gross oil column now proven in the main Sea Lion southern fan is 104m (341 ft).

3 metres of net oil pay is present in the lower sands; these thin oil sands are below the water leg of the upper sands indicating at least one additional oil column. The lower fan encountered in 14/10-2 was neither strongly developed nor prognosed at this location, but the thin lower oil sands at 14/10-4 confirm prospectivity for lower fan sequences developed elsewhere downdip.

A mini-DST (wireline drill stem test) was performed using a dual-packer MDT tool over a one metre interval at 2486 metres (drilled depth) within the oil column. This test successfully flowed oil into the wellbore, providing additional samples and pressure build-up data. These data indicate that flow rates and producibility at the location could be significantly better than at 14/10-2.  A single MDT sample chamber was opened on the rig and initial wellsite analysis indicates a medium grade oil similar to that in 14/10-2.

An oil-water contact (OWC) is indicated from cores, wireline logs and MDT pressure and sampling data at a depth of 2503 metres drilled (2477 metres true vertical depth subsea).

The northern fan penetrated by the 14/10-3 well is represented as a thin sand at the base of the main section at this location. The sand was within the water column. Potential remains in the main northern fan updip of this location.

57.5 metres (189 feet) of conventional core was cut in two cores from near the top of the reservoir with 100% recovery. The extensive reservoir information from cores, wireline logs, seismic and wireline MDT test data is being evaluated to establish reservoir extent across the area for both the Upper and Lower fan systems.

Rockhopper believe the results of this successful first appraisal well will significantly increase the contingent P90 volume for this oil discovery. The P50 and P10 contingent volumes will be defined as the appraisal programme progresses through the remainder of 2011.

The well will now by plugged and abandoned as planned.  The Ocean Guardian semi-submersible rig will then proceed to drill the Ninky prospect in which Rockhopper has a non-operated 7.5% working interest. Following completion of the Ninky well, Rockhopper intends to drill a minimum of three further appraisal wells on the Sea Lion feature.  The Company is currently considering extending that campaign to include additional appraisal and exploration wells.

Following this well, Rockhopper will commence work on development planning for the Sea Lion discovery.

Samuel Moody, Chief Executive, commented:

"Following this positive result we believe Sea Lion is highly likely to prove commercially viable.  The well has confirmed our ability to identify good reservoir units on the seismic in our acreage with the sands coming in very close to prognosis. We can now continue to appraise the Sea Lion discovery and to explore additional prospectivity within our acreage with added confidence."

Enquiries:

Rockhopper Exploration plc

Sam Moody - Chief Executive

Tel. [phone] (via M: Communications)

M: Communications

Patrick d'Ancona or Ben Simons

Tel. [phone]

Canaccord Genuity Limited

Charles Berkeley / Henry Fitzgerald-O'Connor

Tel. [phone]

Notes to Editors

Rockhopper was established in February 2004 with a strategy to invest in and carry out an offshore oil exploration programme to the north of the Falkland Islands. The Company floated on AIM in August 2005 and holds a 100 per cent. interest in four offshore production licences: PL023, PL024, PL032 and PL033 which cover approximately 3,800 sq. km. Rockhopper has also farmed in (7.5% working interest) to licences PL003 and PL004, which are operated by Desire Petroleum. These licences have been granted by the Falkland Islands government.

An extensive work programme has been carried out over a number of years on the licences operated by Rockhopper. This has included 2D and 3D Seismic and Controlled Source Electromagnetic Mapping (CSEM). In February 2010, the Ocean Guardian drilling rig arrived in Falkland waters to carry out a multi-well drilling campaign. Rockhopper drilled an exploration well on its Sea Lion prospect during April and May 2010, the result of which was the first oil discovery and Contingent Oil Resource in the North Falkland Basin. The Sea Lion discovery was successfully tested during September 2010 and was the first oil to flow to surface in Falkland Islands waters. Rockhopper has contracted seismic vessels MV Polarcus Asima and Nadia to carry out a 3D seismic survey, beginning December 2010, over areas of licences PL024, PL032 and PL033 which were not previously defined by 3D, as well as adjacent areas.

 Rockhopper Exploration plc www.rockhopperexploration.co.uk

NB: This statement has been approved by the Company's geological staff who include David Bodecott (Exploration Director), who is a Member of Petroleum Exploration Society of Great Britain (PESGB) and the American Association of Petroleum Geologists (AAPG) with over 30 years of experience in petroleum exploration and management, for the purpose of the Guidance Note for Mining, Oil and Gas Companies issued by the London Stock Exchange in respect of AIM companies, which outline standards of disclosure for mineral projects.

 

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