Drilling Update: Perth Basin

Roc Oil Company Limited
21 May 2007


21 May 2007


                         ROC OIL COMPANY LIMITED ('ROC')
                             STOCK EXCHANGE RELEASE

     DRILLING ACTIVITY UPDATE: OFFSHORE PERTH BASIN EXPLORATION DRILLING -
                                 PERSEVERANCE-1

Roc Oil (WA) Pty Limited, a wholly owned subsidiary of ROC, advises that the
Perseverance-1 exploration well in WA-325-P, offshore Perth Basin, has been
drilled to a Total Depth of 1,774 metres and that, as of 0600 hours on 21 May
2007, Australian Western Standard Time ('AWST'), the current operation was
running electric logs.

Since the last Stock Exchange Release on 15 May 2007, the well has penetrated
the two main objectives, the Dongara Sandstone and the Irwin River Coal
Measures. Drilling and preliminary log data indicate that good gas indications
are present in sands with moderate reservoir quality over a gross interval of
approximately 32 metres below the top of the Dongara Sandstone. The significance
of the gas shows will be determined after logging has been completed.

Perseverance-1, the second of a three well exploration drilling programme in the
region, is scheduled to be followed by Dunsborough-1 in WA-286-P.

Participating Interests in WA-325-P are:
    Roc Oil (WA) Pty Ltd (Operator)......................................37.5%
    Apache Northwest Pty Limited.........................................37.5%
    ARC (Offshore PB) Limited............................................20.0%
    Wandoo Petroleum Pty Ltd. (Mitsui & Co Group of Companies)............5.0%*
    *Subject to a purchase agreement with ARC Energy


Damian Fisher
General Manager
External Affairs & Investor Relations

                                         For further information please contact:
                                                                Dr John Doran on
                                                            Tel: [phone]
                                                            Fax: [phone]
                                                     Email: [e-mail]
                                       Or visit ROC's website: www.rocoil.com.au
                                                                                
                                                                                
                                                                   Dr Kevin Hird
                                          General Manager - Business Development
                                           Tel: [phone]
                                            Mob: [phone]
                                                     Email:  [e-mail]
                                                                                
                                                                    Nick Lambert
                                            Bell Pottinger Corporate & Financial
                                                       Tel:  [phone]
                                                                                


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