announcement

ASX RELEASE
To: Australian Stock Exchange Ltd No of Pages: 1
RE: Tarantula 1 Sidetrack gas exploration well update 6
ARC Energy Limited advises that at 0600 hours WST today operations on the gas exploration well
Tarantula 1 Sidetrack 1 (Tarantula 1ST1), operated by Origin Energy and located in the onshore Perth Basin Production Licence L11, was at total depth of 3,330 metres and conditioning hole prior Since the last report the well has been drilled to total depth of 3,330 metres in 152mm (6”) hole.

Wireline logging of the well, including pressure testing of the reservoir section has also been completed. Logging has confirmed gas saturations in two zones over a gross interval of 32 metres between 3,228 metres measured depth and 3,279 metres measured depth of which approximately 10 metres is interpreted to be good to excellent quality reservoir sands. The lower zone is interpreted to be equivalent to the gas producing horizon in the Beharra Sprngs and Beharra Springs North gas Pressure data obtained during the evaluation of these sections in Tarantula 1 indicates good permeability to gas is present in both zones and that a significant gas column could be present.
The forward plan is to run a slotted liner over the reservoir section to complete the well, prior to release of the rig to the Jingemia development drilling program. The well will then be flowed to unload completion fluid and suspended prior to tie in to the existing Beharra Springs facilities.

Participants in L11 and Tarantula 1 are:
• Origin Energy Developments Pty Ltd - 67% (a wholly owned subsidiary of Origin Energy
Director