announcement

Monday 20 September 2004
Australian Stock Exchange ELS492005
Company Announcements Office
Electronic Lodgement System
ARWON-1 EXPLORATION WELL
Cooper Energy NL advises the Arwon-1 wildcat well (PEL 93 and PEL 113) is expected
to spud on Thursday 23 September 2004.
Arwon-1 is located approximately 2.5 kilometres east-northeast of the Worrior oil field
(Attachment 1), currently producing in excess of 2,000 barrels of oil per day, and
approximately 55 kilometres southwest of the Moomba oil and gas processing plant.
The Arwon prospect straddles the boundary of PEL 93 and PEL 113. Cooper Energy
holds 30% of PEL93 and 0% of PEL113, and has an 11.2% working interest in the well
and any subsequent discovery.
The well is being drilled principally as an oil prospect to test for oil in the McKinlay,
Birkhead and Hutton reservoirs. It will also test a secondary target for gas in the lowermost
Patchawarra Formation. The assessed potential 2P ultimate recovery for Arwon
is 5 million barrels.
The Arwon prospect is a four way dip closure anticline that is thought to be on the
hydrocarbon migration path for the Worrior prospect, which increases the chances of
success for the well. The well is interpreted to have a 46% chance of success, which is
slightly higher than that normally carried for an exploration well.
The well will test three primary targets; the McKinlay, Birkhead and Hutton Formations;
prognosed to be intersected at 1,374 metres, 1,574 metres and 1,636 metres,
respectively. Two secondary targets, the Epsilon and Patchawarra Formations, at
1,746 metres and 1,780 metres will also be tested by the well.
Arwon-1 is expected to intersect the McKinlay Formation approximately six days after
spud and take 14 days to reach the total planned depth of 1,930 metres.
Stuart Petroleum is the operator of Arwon-1.
Yours faithfully
COOPER ENERGY NL
Michael Scott
CHIEF EXECUTIVE OFFICER