Drilling Update: Perth Basin

Roc Oil Company Limited
23 April 2007


23 April 2007

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

                            Drilling Activity Update:
             Offshore Perth Basin Exploration Drilling - Frankland-1

KEY POINT

•   The Frankland-1 exploration well, in WA-286-P in the offshore Perth
    Basin, is being plugged and abandoned as a gas discovery. The discovery
    needs to be evaluated in more detail to determine its size and whether or
    not an associated oil log is present. Preliminary indications suggest that
    the structure could contain between 60 and 90 billion cubic feet of gas
    in-place and that if an oil leg exists it is likely to be small.


Roc Oil (WA) Pty Limited advises that, as of 0600 hrs on 23 April 2007
Australian Western Standard Time ('AWST'), the Frankland-1 well was being
plugged and abandoned as a gas discovery. Since the last Drilling Report on 17
April, 2007, the well drilled to a Total Depth of 2,340 metres Below Rotary
Table ('mBRT') and an extensive evaluation programme was carried out.

Preliminary interpretation of wireline and pressure data suggests that the well
intersected 35 metres of gas saturated sand of which approximately 28 metres
appear to be net pay of moderate to good quality. The gas sand is at the top of
the objective section at 1,986 mBRT and is interpreted as being equivalent to
the Dongara Sandstone. Underlying the gas sand there are 232 meters of shales
interbedded with generally tight sands with gas indications down to
approximately 2,065 mBRT. Below this shale-sand sequence there are several
water-bearing sands near Total Depth. An obvious gas-water contact was not seen
in the well and further evaluation is required to determine how much of the
structure, which has a vertical relief of more than 100 m, is gas filled.
Initial calculations for the 35 metre gas sand suggest in-place gas could range
between 60 and 90 billion cubic feet. On balance the well data suggest that if
an oil leg is present it is likely to be small.

The forward programme for the 'Premier Wilcraft' rig is to move to the
Perserverance-1 exploration well location in WA-325-P, approximately 80 km north
of Frankland-1, where drilling is expected to start prior to the end of the
week.

Participating Interests in WA-286-P are:

Roc Oil (WA) Pty Ltd (Operator)..............................37.5%
AWE Oil (Western Australia) Pty Ltd..........................27.5%
Wandoo Petroleum Pty Ltd (Mitsui & Co Group of Companies)....24.0%
ARC (Offshore PB) Limited.....................................6.0%
CIECO Exploration and Production (Australia) Pty Ltd..........5.0%

In accordance with ASX Listing Rules and AIM Rules, the information in this
Release has been reviewed and signed off by Dr John Doran, Chief Executive
Officer, Roc Oil Company Limited, BSc (Hons) Geology; MSc and PhD. Dr Doran has
at least five years' relevant experience within the sector and consents to the
information in the form and context in which it appears.



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]
                                                       Fax:  [phone]
                                                     Email:  [e-mail]
                                                                                
                                                                    Nick Lambert
                                            Bell Pottinger Corporate & Financial
                                                       Tel:  [phone]
                                                                                


                      This information is provided by RNS
            The company news service from the London Stock Exchange