Stage 5 involves building an additional 570km of parallel pipes (looping) as well as further modifications to compressor stations. First delivery of the additional 100 terajoules of gas transmission capacity is expected in the first quarter of 2008.

But DBP today said it had received a number of “firm capacity requests” that are likely to lead to an extension of the Stage 5 pipeline expansion – to be known as Stage 5A(2).

“The Stage 5A(2) expansion is being investigated in response to shipper demand for additional firm full haul and part haul capacity,” it said.

“Shippers would take all of this additional capacity under long-term contractual arrangements.”

If it went ahead, the extension would provide another 40TJ per day of firm full haul capacity – bringing the maximum full haul capacity of the DBNGP to about 825TJpd.

DBP executive chairman Stuart Hohnen said he expects the Stage 5A(2) extension to be commissioned over 2009 and 2010.

“The project would consist primarily of further looping – involving additional pipe being laid alongside the existing pipeline,” he said.

Hohnen said design and costing work was still at an early stage but the capital cost for Stage 5A(2) is expected to be about $200 million and would be funded through debt and equity capital.

DBP said it will work with lenders, construction contractors and shareholders to develop the investment case and hopes to have final approvals for the extension during the 2007 third quarter.

Stage 5A is the first component of the larger three-part Stage 5 project, announced in early 2006.

DBP is majority-owned by DUET (Diversified Utility and Energy Trusts), with Alcoa and Alinta as minority owners.