Subsea 7 laid the 65-km (40.4-mi) line which connects production from theSole field wells to the onshore Orbost Gas Plant. There are no hydrocarbons in the pipeline at present.
An acceptance pressure test of the line with water (hydrotest) revealed an anomaly was preventing the pipeline from holding internal pressure.
This was identified subsequently as a through-wall thickness opening at one location. The opening has been observed in the pipe itself and not at a weld, Cooper stressed.
Subsea 7 is assessing the damage to the pipeline and working on plans for a repair, prior to completing the hydrotest.
Cooper expects commercial gas sales to start as scheduled next July.