Origin Spuds Thistle Well

Origin Energy, on behalf of the VIC/P43 Joint Venture, advises that the Thistle 1 exploration well, located in Otway Basin, Victoria, has spud on 03:30 hours EDT on Thursday, April 19, 2012. The well is being drilled using the semisubmersible drilling rig Stena Clyde (mid-water semisub).

Origin will only advise the market again when well operations have been completed with a summary of results, or of any event that is material.

Well type and location

Thistle 1 is an exploration well located in exploration permit VIC/P43, operated by Origin some 10 miles (16 kilometers) north-northwest of the Geographe gas field.

Thistle 1 is a vertical well. The final surface location is:

• Latitude: 38 degrees 57' 59.857" S
• Longitude: 142 degrees 53' 27.748" E

Planned total depth of the well is 2,559mRT (2,534mTVDSS). The well will be plugged and abandoned after the evaluation program is completed.

VIC/P43 Participating Interests:

• Origin Energy Resources Ltd  - Operator 67.23%
• Benaris Exploration (Otway) Pty Ltd 27.77%
• Toyota Tsusho Gas E&P Otway Limited