In the 1960s, Brisbane became the first Australian capital city to receive an ongoing natural gas supply for commercial and domestic use. The 438 km, 300 mm diameter Roma to Brisbane Pipeline (RBP) took 12 months to construct and was completed in 1969 at a cost of $11 million. Gas was supplied at Wallumbilla from both local gas producers in the Surat Basin, and since the late 1990s has also been sourced from South West Queensland producers via a pipeline from Ballera.

The RBP’s first major customer was Incitec, a fertiliser manufacturer, with the balance of the capacity sold to South Brisbane Gas Company. Major customers now include CS Energy’s Swanbank Power Station, BP’s Bulwer Island Refinery, the South West Queensland producers and energy retailers AGL and Origin Energy.

The RBP has undergone significant expansion since the late 1980s, with capacity increasing five-fold through the installation of six compressor stations at Yuleba, Condamine, Kogan, Dalby, Oakey and Gatton, and pipeline duplication via six stages of looping, a total of 403 km.

New inlet stations have been constructed to receive CSG from new production areas in southern Queensland. In 2001, the 121 km, 250 mm diameter Peat Lateral was constructed for the Peat and Scotia gas fields to Arubial. The pipeline, including the Peat Lateral, is a covered pipeline and is regulated by the Australian Energy Regulator.

The RBP Expansion Program

RBP is currently fully contracted and the 2011–12 expansion project will increase the capacity by approximately 10 per cent to 232 TJ/d. The RBP Expansion Program consists of four projects:

  • A 5.8 km, 400 mm diameter,
  • API 5L X80 steel pipeline looping part of the metropolitan section of the pipeline from the Murarrie delivery station to Preston Road, near Brisbane’s Gateway Bridge;
  • A new Solar Centaur 50 compressor at the existing Dalby compressor station;
  • Increasing the maximum operating pressure of the pipeline from 8 MPa to 9.3 MPa from Wallumbilla to Condamine and to 9.6 MPa from Condamine to Ellengrove; and,
  • Upgrade of the Ellengrove meter station for the increased capacity requirements.

Design work and environmental approvals are now complete and the pipe has been sourced and ordered from Orrcon Steel. Due to its large size and 12.7 mm wall thickness, the pipe for the looping will have to be manufactured overseas.

Project challenges

There are a number of challenges associated with the expansion project, in particular a tight schedule, with three of the four projects having similar commissioning dates.

“The overall program time-frame is approximately 14 months from final investment decision to first gas, with all four projects requiring completion to enable delivery of the new contracted quantities,” says APA General Manager Projects Robert McMaster.

“Management of the project is crucial to ensuring resources and field activities are prioritised across the program to avoid conflicts and ensure the project stays on schedule.”

Another challenge is the uncertainty of weather effects. “The floods experienced in South East Queensland in 2011 created major challenges for utility infrastructure, including APA’s pipeline and gas networks,” says Mr McMaster. “All elements of the RBP expansion are located within South East Queensland, hence there is the threat of potential project delays if there is a repeat of the inclement weather.”

To mitigate potential problems such as damage and delays, work has been done in relation to construction timing and methodology. As an example, in low-lying areas of the pipeline route, horizontal directional drilling lengths have been extended to avoid restricted access of excavation machinery to the easement following wet weather. At other sites, timing of activities such as bulk earthworks have been brought forward to ensure a stable work platform at a suitable level is in place prior to the wet season.

The third major challenge is maintaining gas supply during construction and commissioning as all projects involve working on or adjacent to existing operational assets. Mr McMaster says “Planning is critical, including ensuring design alterations allow for sufficient isolation and connection points to avoid interruptions to supply. Co-ordination with APA’s operations division is another key component of the project planning to ensure all construction activities comply with correct asset protection work practices and are properly permitted and supervised.”

The expansion works are planned for completion in winter 2012.