The Northern Territory (NT), more than any other Australian state or territory, relies on natural gas to generate almost all of its electricity requirements. As the contracted quantities of gas from the Amadeus Basin reduce in volume, the Bonaparte Gas Pipeline (BGP) will become the major gas supply artery for the entire NT.

Project development began in early 2006, with the pipelne becoming operational on 10 December 2008, ahead of the contracted first gas date of 1 January 2009.

APA Group Manager of Operations Stephen Ohl said “It is a tribute to all those involved in this project that through one of the most difficult periods ever – with labour shortages, material price escalation and long equipment delivery times – the project team has brought this project in on schedule at a cost that allows gas to be transported economically to meet the NT’s energy needs.

“In addition to the APA team and our contractors, the contribution of staff at Power Water Corporation (PWC), the Northern Land Council (NLC), the NT Government and all the traditional and pastoral landholders need to be acknowledged as it is only through the support of all involved that a project like this can be successfully completed.”

The BGP is now owned by the unlisted company, Energy Infrastructure Investments (EII), which comprises the interests of Marubeni, Osaka Gas and APA Group. The pipeline constitutes a major asset in this company’s portfolio of investments.

APA Group Managing Director Mick McCormack said “As the 96 per cent owner of NT Gas, APA has had a presence in the NT since its inception and now, as part owner of EII and through its role as the operator of the BGP, the APA Group has increased it’s commitment to the NT and looks forward to growing this commitment into the future.

“This commitment to the development of the NT is further demonstrated by APA constructing and operating the EII-owned Wickham Point Pipeline so that PWC can further enhance security of supply for all NT energy users,” he said.

Mr McCormack continued “With Blacktip natural gas, the residual gas supply from the Amadeus Basin and the environmental advantages of natural gas, the use of natural gas in the NT is set to expand both through the APA NT Gas Distribution system and the development of pipelines to supply new and existing users like mine sites. APA intends to be a major part of these future developments.

“In addition to our long term business commitment to the NT we have also been a long time sponsor of the Darwin Symphony Orchestra (DSO). To commemorate the construction of the BGP, APA has commissioned a short orchestral composition written by Darwin based composer, Cathy Applegate. This composition will have its world premiere, played by the DSO, at a concert in the NT in mid-2009.”

Pipeline project planning

Due to the need for first gas by 1 January 2009, APA commenced work on the pipeline planning before any agreements had been executed. Initial pipeline design, route selection and capital costing was carried out in-house and formed the basis for the gas transportation agreement signed with PWC. Stephen Dykes was appointed Project Manager in April 2006 and project planning commenced in earnest.

In 2006, APA had limited in-house resources and Mr Dykes set about assembling a project team and structure that could develop and construct the pipeline. By June 2006, the initial project team included managers for lands and environment, licensing, risk and safety, an Environmental Co-ordinator and a Lands Officer, with a Manager for Technical Services joining the team in July. In addition, contracts had been let to Mipela to provide mapping services, EcOz to provide environmental services and WorleyParsons for preliminary engineering services.

The logistics for this project team were challenging with team members and contractors variously based in Brisbane, Sydney, Melbourne, Canberra and Darwin. APA set up project offices in Brisbane and Darwin with the team travelling as required to co-ordinate activities. As the project moved closer to execution the Brisbane project office was closed and all activities were based out of the Darwin office.

Land access

The pipeline route runs through two main land tenure areas. The first 130 km from Wadeye to just west of the Daly River is in Aboriginal freehold land and the remainder of the route is through pastoral lease land including Elizabeth Downs, Tipperary and Ban Ban Springs stations. There are also other small tenure areas including a stock route, a mining lease, and road and rail crossings.

While both PWC and APA worked together on acquiring all the land access agreements, PWC was responsible for acquiring all land access agreements relating to the Aboriginal freehold land and for agreements relating to Cultural Heritage and Native Tile obligations across the whole route. Both PWC and APA worked with the NLC throughout the project to ensure that the traditional owners were involved in route selection and that cultural heritage concerns were addressed and appropriate compensation arrangements were agreed.

APA was responsible for acquiring the easements and related agreements over the 157 km of the pipeline route that is not on Aboriginal freehold land. These negotiations, while ultimately successful, were complicated by management changes at some of the stations and by a company holding a mining lease over part of the pipeline route.

In addition to the normal land access arrangements, APA has also provided the opportunity for the traditional owners, via the NLC, to acquire an equity interest in the project. To date this interest has not been taken up.

Environmental approval

Based on APA’s July 2006 Notice of Intent (NoI) to the NT Government and the referral under the Environment Protection and Biodiversity Conservation Act (EPBC) to the Commonwealth Government, the project was designated as a controlled action for threatened and migratory species. This allowed the Public Environment Report (PER) for the project to be developed and assessed under the bilateral agreement between the NT and Commonwealth governments.

Using the September 2006 draft terms of reference for the PER, detailed field studies commenced in November 2006. The PER was issued for public comment in March 2007 and included copies of the draft construction environmental management plan and draft road use management plan. Following receipt of public comments, a supplementary PER was issued in May 2007 and PER approval was finalised in June 2007. EPBC approval was finalised in September 2007 by the Commonwealth Government.

Some of the environmental issues identified by the project included:

* Construction was not to impact on any Acacia Praetermissa (Mimosaceac) plants identified; * Permanent habitat modification of other EPBC Act listed species including, but not limited to Erythura Gouldiae (Gouldian Finch) and Dasyurus Hallucatus (Northern Quoll), must not exceed 120 ha; * Measures must be in place to prevent permanent impacts at watercourse on EPBC listed species such as Pristis Microdon (Freshwater Sawfish) and Xeromysm Yoides (Water Mouse). Horizontal directional drilling (HDD) was used for crossing the Daly Rivers, Tom Turners Creek and the two arms of Green Ant Creek; * Maximum length of open trench to be limited to 60 km; * Appropriately trained fauna handlers to be employed to ensure that the open trench was cleared at least daily; and, * The road use management plan must include management measures that specifically addressed safety issues associated with traffic movement along the Wadeye to Daly River Road.

Detailed design and procurement

Following on from its role as the preliminary engineering service provider, WorleyParsons was further contracted in November 2006 to provide detailed engineering and procurement services for the total project. During early planning the pipeline’s expected design, which was 300 mm NB, 15.3 MPa maximum allowable operating pressure and approximately 275 km in length. The main changes for the final design was that, due to the number of route changes, the pipeline length increased to 287 km and the pipeline was designed and constructed in accordance with the newly introduced AS2885 Part 1 2007.

Using the new design code, this pipeline was one of the first to be constructed and operated at 80 per cent specified minimum yield strength. The length increase was due to a number of route modifications needed to meet traditional owner and station owner requirements, as well as one change to move the pipeline away from a potential future gold mining area.

The pipeline design included an inlet scraper station and maintenance base at Wadeye, two mainline valve sites, an intermediate scraper station with provision for a future compressor station and the delivery point scraper, regulation and metering station adjacent to the connection into the existing Amadeus Basin to Darwin Pipeline at Ban Ban Springs.

Following tendering, the supply contract for coated line pipe to be delivered to Darwin was awarded to Orrcon in October 2007, with orders for other major materials being placed progressively thereafter. APA ordered these long lead time materials ahead of awarding the main construction contract to keep the project on schedule and to ensure that the materials would be available for handover to the selected construction contractor.

Pipeline construction

After a significant amount of analysis and review, APA decided to adopt a modified Early Contractor Involvement model as the contracting approach best suited to the project requirements. Four construction contractors were pre-qualified for the project and the construction invitation to tender was issued in early June 2007. The stage one construction contract was awarded to AJ Lucas in early October 2007. APA and AJ Lucas then worked together to further define the risks and costs relevant to the final construction contract with the stage two construction contract award to AJ Lucas being confirmed in January 2008.

Having only the 2008 dry season, which runs from April to November, to complete the pipeline, it was important for the contractor to commence mobilisation as soon as weather permitted. The project plan was for construction to commence at the eastern end of the pipeline from Ban Ban Springs, since this was accessible via all weather roads. Construction then worked west so that it did not reach the Daly River and the Daly River to Wadeye Road until the area had substantially dried out after the end of the wet season.

The NT Government consent to construct and the APA approval for construction access to the right of way were issued in March 2008 and mobilisation to site commenced. Following construction of Camp 1, clear and grade commenced in April with all other mainline construction activities commencing in May.

Early construction progress was slowed somewhat by delays in the delivery of line pipe and the Australian-wide competition for experienced project and construction personnel. Despite this slower than planned start, the clear and grade had crossed the Daly River by the end of June with all other activities progressing toward the Daly River.

By the end of July, all three HDDs had been successfully completed; both arms of Green Ant Creek (1,536 m), the Daly River (400 m) and Tom Turners Creek (275 m). Line pipe delivery was completed in early August with hydrostatic testing commencing later that month, as did the construction of the pipeline facilities.

Mainline welding was completed at the end of September and all mainline construction was essentially complete by the end of October. Pipeline hydrostatic testing, gauging and facilities construction was completed early in December, with natural gas being introduced into the pipeline shortly thereafter. Because natural gas was not available at Wadeye, Amadeus Basin gas was used to commission the pipeline from east to west, the opposite direction to its normal mode of operation.

The NT Government issued the consent to operate on 10 December 2008, and the operation and maintenance of the pipeline was handed over to NT Gas well in time for the contracted 1 January 2009 first gas date.

Safety, risk and compliance

As with all projects of this magnitude, a considerable effort was directed toward putting in place and managing systems, processes and procedures to ensure that the project would be delivered safely, all risks identified and managed, and compliance requirements met. As well as the APA Site Construction Manager and APA Construction Liaison Officers, APA also had full time Safety, Compliance and Environment Officers on site with the construction team. This role was supported by APA auditors visiting the construction site a number of times over the period of construction.

An APA-sourced engineering support team was used extensively to ensure compliance with the requirements of AS2885. This team provided compliance approval for activities requiring approval under this Standard. It proved an essential part of the project and enabled the application of sound procedures processes and practices. The team facilitated a clear compliant process for the Technical Regulator to review and evaluate. Consequently, there were no delays in gaining the appropriate consents and approvals throughout the construction phase of the project.

During very early project planning, one of the major issues identified was the risk of accidents and injuries due to traffic on the Daly River to Wadeye road. This road is unsealed, very dusty and normally carries very little traffic such that local residents use the road as a footpath as well as a thoroughfare. The project’s road use management plan was put in place to manage this risk and, in association with the NT Government, the road speed limit was reduced to 80 km per hour, large signs were erected along the road warning people of the additional project traffic, and project travel at night was prohibited unless absolutely necessary.

In addition to the very substantial effort directed to driving safety, other pro-active measures used on the project included tool box meetings; random fitness for work testing with over 1,500 tests conducted during construction; and, a hazard alert reporting system with over 350 alerts issued and resolved.

First gas

While the BGP project is operational and has been completed on schedule, the Eni Blacktip development and onshore gas plant construction is running behind schedule and fine tuning on the pipeline cannot be made until the Blacktip gas supply is available. As at the date of writing, no new gas delivery date had been advised, but it is expected to occur around mid-2009. In the meantime, NT Gas staff are maintaining and operating the pipeline to ensure compliance with all licence and code obligations.

APA is keen to see the day when Blacktip gas starts to supply the energy needs of the Territory. The company looks forward to seeing an environmentally friendly and secure gas supply that will continue and expand for at least 25 years.