Drilling Activity Update

Roc Oil Company Limited
23 February 2005




23 February 2005

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

                            DRILLING ACTIVITY UPDATE

KEY POINT

•   Cliff Head-5 ('CH-5'), an appraisal well in the Cliff Head Oil Field,
    offshore Western Australia, has encountered the top of the anticipated
    reservoir substantially low to prognosis.


Roc Oil (WA) Pty Ltd, as Operator of the WA-286-P Joint Venture (the 'Joint
Venture'), advises that the CH-5 appraisal well has encountered the top of the
anticipated reservoir approximately 50 metres low to prognosis just above the
field wide oil-water contact and as of 0600 hours on Wednesday 23 February
(Australian Western Standard Time) was drilling ahead at 1,492 metres to
basement.

CH-5 is a vertical 'pathfinder' well located about 1 km southeast of the CH-1
discovery well (Attachment 1*). The pre-drill plan for CH-5 was that it be
plugged and abandoned because its primary purpose was to determine the nature
and extent of the reservoir in the East Ridge portion of the Cliff Head
structure so as to better define the location of a horizontal development well.

It is currently not understood whether CH-5 has come in low to prognosis due to
adverse seismic velocity variations which would have an adverse impact on field
reserves, or due to drilling inadvertently on the wrong side of a nearby fault,
which would probably have a less severe impact on field reserves.

The Joint Venture is actively reviewing the data obtained to date and will
integrate that information with the results of the logging programme over the
next 48 hours. At the moment, it is too early to comment definitively as to
whether or not CH-5 was optimally located in relation to a nearby fault. If the
full data set indicates that the CH-5 location was less than structurally
optimal, the Joint Venture may consider sidetracking the well.

Regardless of the outcome of CH-5, upon completion of well operations the rig
will move to drill the CH-6 development well location in the main horst part of
the Cliff Head structure.

Commenting on preliminary results from CH-5, Dr John Doran, ROC's Chief
Executive Officer, stated that:

'With the results we have seen so far from CH-5 it is pretty clear why we
described the well as a 'pathfinder'. If we have ended up on the 'wrong side' of
the fault, then the situation may possibly be rectified by a sidetrack to the
east. If, however, we are on the 'right' side of the fault, the fact that the
top reservoir has been encountered substantially lower than prognosed means that
we need to greatly improve our understanding of the East Ridge portion of the
Cliff Head structure and this will impact on the details and timing of the Final
Investment Decision for the development of the field.'

The WA-286-P Joint Venture comprises: Equity

    Roc Oil (WA) Pty Ltd (Operator).....................37.5%
    AWE Oil (Western Australia) Pty Ltd ................27.5%
    Wandoo Petroleum Pty Ltd ...........................24.0%
    Voyager (PB) Limited ................................6.0%
    CIECO Exploration and Production
    (Australia) Pty Ltd .................................5.0%

*For Attachment 1 see copy of this release on ROC's website
(http://www.rocoil.com.au/Pages/ASX_Releases/2005_Releases/February-2005.html)

Bruce Clement                            For further information please contact:
Chief Operating Officer                                         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]
                                                       Fax:  [phone]
                                                     Email:  [e-mail]

                                                                    Nick Lambert
                                            Bell Pottinger Corporate & Financial
                                                       Tel:  [phone]



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