Oil Discovery Offshore China

Roc Oil Company Limited
10 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 was
being 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, offshore
China (Attachment 1#).

Preliminary analysis of the initial log data indicates that the gross reservoir
interval targeted by the well - sands within the Weizhou Formation of Oligocene
age - contains numerous oil-bearing sands. The top of the highest oil sand is at
about 1,950 mBRT and the base of the lowest oil sand is at 2,450 mBRT. The
intervening 500 metres is comprised of a gross sand-shale-silt sequence within
which individual oil-bearing sands range up to 25 metres in thickness. The total
collective net thickness of these oil sands is approximately 100 metres which
substantially exceeds the Joint Venture's most likely pre-drill expectation.
Consistent with such a thick net oil pay interval, reservoir characteristics
vary in fine detail but generally the majority of the oil-bearing sands display
good reservoir quality.

The Wei-6-12S prospect represents an unusual structural target: the area of
structural closure is relatively small (about one sq km) but the vertical
structural closure is considerable (up to 95 metres) and the gross prospective
reservoir section is very thick (500 metres). The well, which was designed to
penetrate most of the target sands about 30 metres down dip from the crest of
the structure, is located in about 30 metres of water, approximately 3 km
southwest 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 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

# 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 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: [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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