Rockpool Acqui Regulatory News (ROC)

10 May 2006 07:01

Roc Oil Company Limited10 May 2006 10 May 2006 ROC OIL COMPANY LIMITED ("ROC") STOCK EXCHANGE RELEASE EXPLORATION DRILLING UPDATE: WEI-6-12S-1 OIL DISCOVERY, OFFSHORE CHINA KEY POINTS • Preliminary analysis of initial wireline log data indicates that the Wei-6-12S-1 exploration well, in Block 22/12 in the Beibu Gulf, offshore China, is a potentially significant oil discovery. • A gross interval of about 500 metres contains numerous separate reservoir sands which collectively represent approximately 100 metres of net oil pay with generally good reservoir characteristics. Overall individual sands range in thickness up to 25 metres. • The Block 22/12 Joint Venture is currently giving consideration to immediate appraisal. As at 0600 hours (local time) on 10 May 2006, a wireline logging programme wasbeing conducted, at a Total Depth of 2,535 metres below rotary table ("mBRT"),at the Wei-6-12S-1 exploration well in Block 22/12, in the Beibu Gulf, offshoreChina (Attachment 1#). Preliminary analysis of the initial log data indicates that the gross reservoirinterval targeted by the well - sands within the Weizhou Formation of Oligoceneage - contains numerous oil-bearing sands. The top of the highest oil sand is atabout 1,950 mBRT and the base of the lowest oil sand is at 2,450 mBRT. Theintervening 500 metres is comprised of a gross sand-shale-silt sequence withinwhich individual oil-bearing sands range up to 25 metres in thickness. The totalcollective net thickness of these oil sands is approximately 100 metres whichsubstantially exceeds the Joint Venture's most likely pre-drill expectation.Consistent with such a thick net oil pay interval, reservoir characteristicsvary in fine detail but generally the majority of the oil-bearing sands displaygood reservoir quality. The Wei-6-12S prospect represents an unusual structural target: the area ofstructural closure is relatively small (about one sq km) but the verticalstructural closure is considerable (up to 95 metres) and the gross prospectivereservoir section is very thick (500 metres). The well, which was designed topenetrate most of the target sands about 30 metres down dip from the crest ofthe structure, is located in about 30 metres of water, approximately 3 kmsouthwest of the 2002 Wei-6-12-1 oil discovery. Commenting upon the discovery ROC's Chief Executive Dr John Doran stated that: "• Anytime you get a 100 metres of good quality net oil pay, way beyond pre-drill expectations, you can be forgiven for being cautiously optimistic. • Prior to drilling the well ROC had two main technical concerns: trap integrity and the structure's relatively small areal closure. Subsequent to drilling we no longer have those concerns. The integrity of the trap is self evident and although the structure does have a limited areal extent, that factor is more than offset by the thickness of the multiple reservoir sand sequence. • It will take many weeks to collect and analyse all the data to the point where we can begin to offer detailed comments on field size and commercial implications. In the meantime, we can safely say that this well has delivered a handsome discovery that certainly merits further appraisal." The Block 22/12 Joint Venture comprises*: Roc Oil (China) Company 40% and OperatorHorizon Oil Limited 30%Petsec Energy Ltd 25%Oil Australia Pty Ltd** 5% \* The China National Offshore Oil Company ("CNOOC") is entitled to participate upto a 51% funding equity level in any commercial development within Block 22/12. ** A subsidiary of First Australian Resources # Attachment 1 is available with the copy of this release on ROC's website(http://www.rocoil.com.au/Public/Announcement/2006/Exploration_Drilling_Update_Wei-6-12S-1_Oil_Discovery,_Offshore_China_100506.aspx) ________________________________________________________________________________ In accordance with new Alternative Investment Market of the London StockExchange ("AIM") rules the information in this report has been reviewed by anappropriately qualified person with more than 5 years relevant industryexperience, specifically, Dr John Doran, Bsc (Hons) Geology; M.Sc; PhD, ChiefExecutive Officer, Roc Oil Company Limited, and a member of the Society ofPetroleum 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