Wei-6-12S-1, Offshore China

Roc Oil Company Limited 24 May 2006 24 May 2006 ROC OIL COMPANY LIMITED ('ROC') STOCK EXCHANGE RELEASE EXPLORATION DRILLING UPDATE: PRODUCTION TESTING TO COMMENCE AT THE WEI-6-12S-1 OIL DISCOVERY, OFFSHORE CHINA KEY POINT • A three week production testing programme is about to commence at the Wei-6-12S-1 exploration well, offshore China. The programme will test at least three separate zones within a 95 metre net hydrocarbon column. 1. OPERATIONS Since the last Stock Exchange Release on 17 May 2006, the Wei-6-12S-1 exploration well in Block 22/12 in the Beibu Gulf, offshore China, has drilled 6 inch hole to a revised Total Depth of 2,650 metres below rotary table, within the Liushagang Formation, the hydrocarbon generative source interval which underlies the main Weizhou reservoir section. The current operation is preparing for the first of at least three production tests. 2. PRODUCTION TESTING PROGRAMME The production testing programme is designed to provide the Joint Venture with the maximum amount of technical data for possible field development rather than maximum oil flow rates. Consistent with standard industry practice, the deepest zone will be tested first and the shallowest zone tested last. Specifically: • The first production test will be located at the base of the hydrocarbon column in the Lower Sand package immediately above a possible water leg. The purpose of this test is to: confirm whether the hydrocarbon is oil or gas; to determine if a hydrocarbon-water contact is present; and to provide productivity data. • The second test, in the oil pay section within the Middle Sand package, is primarily designed to provide productivity data. • The third test will be at the base of the hydrocarbon column in the Upper Sand package from which oil was recovered during wireline sampling. Pressure data suggest that the oil leg in this sand may extend down dip beyond structural closure. The purpose of the test is to determine the zone's productivity and to gain further insights as to how far down dip this oil bearing reservoir may extend. • A possible fourth test may be undertaken in a zone in the higher part of the Upper Sand package which is gas bearing according to pressure and sample data. The test would supply more information about the nature of the gas and productivity data relating to these sands which will be in the oil leg further down dip. 3. FUTURE APPRAISAL WORK Immediately following the completion of the production testing programme and subject to the results obtained, the Joint Venture intends to drill one or two sidetrack wells from the current well location. These sidetrack wells will have two main aims: to core the relevant parts of the different reservoirs; and/or to identify more accurately the location of some of the hydrocarbon-water contacts which may exist down dip from the current well. The Joint Venture's overall appraisal strategy is to ensure that upon completion of the appraisal programme sufficient data will have been collected to allow the commercial potential of the discovery to be evaluated quickly and thoroughly. If the appraisal results support a commercial development the Joint Venture would immediately commence Feasibility Studies, Front End Engineering and Design and submit an Overall Development Plan to the relevant government authorities in China. As this outcome is unlikely to be determined by the results of any single production test, ROC anticipates that its next Stock Exchange Release, relating to the Wei-6-12S-1 well, will be made in mid-June 2006, when the testing programme is expected to be completed. 4. CEO'S COMMENTS Commenting on the appraisal programme, Dr John Doran, ROC's Chief Executive Officer, stated that: 'Often there is a considerable gap between making an offshore discovery and gathering the appraisal data which is crucial for commercial evaluation. Fortunately, with the Wei-6-12S-1 discovery, ROC and its co-venturers have the opportunity to acquire this information, including production test data, before releasing the rig from its present location. Consequently, when the programme is complete the Joint Venture will be well placed to make a timely and informed decision regarding the field's commercial potential.' The Block 22/12 Joint Venture comprises*: Roc Oil (China) Company 40% and Operator Horizon Oil Limited 30% Petsec Energy Ltd 25% Oil Australia Pty Ltd** 5% *The China National Offshore Oil Company ('CNOOC') is entitled to participate up to a 51% funding equity level in any commercial development within Block 22/12. ** A subsidiary of First Australian Resources In accordance with new Alternative Investment Market of the London Stock Exchange ('AIM') rules the information in this report has been reviewed by an appropriately qualified person with more than 5 years relevant industry experience, specifically, Dr John Doran, Bsc (Hons) Geology; M.Sc; PhD, Chief Executive Officer, Roc Oil Company Limited, and a member of the Society of Petroleum Engineers. Michelle Manook For further information please contact: General Manager - Corporate Affairs Dr John Doran on Tel: +61-2-8356-2000 Fax: +61-2-9380-2635 Email: jdoran@rocoil.com.au Or visit ROC's website: www.rocoil.com.au Dr Kevin Hird General Manager Business Development Tel: +44 (0)207 586 7935 Fax: +44 (0)207 722 3919 Email: khird@rocoil.com.au Nick Lambert Bell Pottinger Corporate & Financial Tel: +44 (0)207 861 3232 This information is provided by RNS The company news service from the London Stock Exchange
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