Looping pipeline in New South Wales: the Young to Wagga Pipeline Looping project

The existing Young to Wagga Pipeline, constructed in 1981, provides gas supply to towns in central south New South Wales including Griffith, Cootamundra, Young and Wagga Wagga. In 1998, the 18 inch Interconnect was built connecting Bomen (Wagga Wagga) and Barnawatha in Victoria. The Young to Wagga Looping project is designed to provide flexibility of supply, security of supply and gas storage.

APA Group’s Young to Wagga Looping project involves the construction of 61km of 18 inch diameter API 5L X70, class 600gas transmission pipeline from Bomen to Bethungra. The looping pipeline will be positioned 7 m away from the operating Young to Wagga Pipeline, with line valves at Wantiool and Bethungra, and cross tie-ins at Bethungra and Bomen. The pipeline has been coated with 600 microns of dual-layer fusion bonded epoxy.

Construction contractor WDS Ltd has mobilised approximately 115 people to work toward the pipeline’s completion, expected by early October 2010. Construction commenced on 25 May 2010.

In 2008, Origin Energy completed construction of the Uranquinty Power Station, located on the Moomba to Sydney Pipeline southern lateral near Wagga Wagga. The power station significantly increased gas demand on this section of the New South Wales transmission system. As such, the pipeline infrastructure was upgraded to meet this increasing demand.

Since then, gas usage for the power station has continued to increase, and a decision to further increase the capacity of the Young to Wagga Pipeline was made in October 2009. This will remove capacity constraints on the Moomba to Sydney southern lateral and provide additional storage capacity for the Uranquinty Power Station.

APA Head of Commercial Energy (East Coast) Ivan Byak said “In the last few years there has been a considerable increase of demand across the Interconnect as shippers look for alternative gas sources to manage their gas portfolio. There are now significant flows both north and south that has seen the pipeline regularly running at full capacity. In addition, the Uranquinty Power Station has required that the storage capacity of the pipeline be increased twice since 2008. We forecast that demand for these services will continue to grow and look forward to announcing the next stage of expansion in this section of the pipeline.”

Navigating new project approval regulations

The Young to Wagga Looping is the first APA pipeline project to go through the new New South Wales major projects approval Part 3A regulations under the Environmental Planning and Assessment Act 1979.

“APA has gone through a very detailed approval process including the approval process for the Construction Environmental Management Plan (CEMP),” said Manager Projects New South Wales, Australian Capital Territory and Western Australia Prakash Mehta.

The Part 3A approval process required preparation and submission of the Environmental Assessment Report (EAR). The EAR was placed on public exhibition, and the submissions received from the New South Wales Department of Planning were responded to in the Submissions Report.

The project was approved with conditions of approval which were incorporated into a CEMP, and are being implemented during construction of the project.

The whole Part 3A approval process took almost 10 months to complete.

In addition, APA conducted town hall meetings with key stakeholders, including property owners along the pipeline alignment, various shire councils, native lands councils, road, rail and water authorities, and the New South Wales Government.

“One of the main issues identified was the new requirements for approval of the CEMP by Department of Planning and the appointment of an independent environmental representative for the project, as one of the measures to ensure and demonstrate compliance with the project conditions of approval and the CEMP.

“Another main issue was the need to develop and implement an offset strategy to demonstrate net gain for the environment,” said Mr Mehta.

There were no native title issues identified along the pipeline alignment however APA has requested that local native land council monitors be in attendance during clearing, grading and trenching operations to ensure that no aboriginal heritage is destroyed inadvertently.

Planning for safety

To ensure workers on the Young to Wagga Pipeline Looping project remain safe, APA and WDS have developed a Construction Safety Management Plan (CSMP) for the project and conduct periodical joint audits to ensure compliance to the plan. No one is allowed to work or visit the site without prior Project Safety Induction training.

Outside the requirements of the CSMP, APA has its own safety procedures which require that all safety-related incidents are reported no later than 24 hours after the event and a job hazard analysis is carried out for each task.

Detailed work method statements are developed for each activity identifying safety hazards and mitigation techniques. A weekly ‘tool box talk’ is also conducted to address any safety issues and the ensure that safety plans are put into action.

Planning for the environment

Environmental protection measures have been included in the work method statement developed for each activity. Periodical audits are carried out by an independent Environmental Representative to ensure all mitigation measures as per CEMP are implemented and effective. Appropriate changes in mitigation measures are implemented based on audit findings.

Construction underway

Construction crews are targeting a production rate in the order of 2 km of pipeline per day.

Temporary facilities for the project include a site office and work areas for materials and equipment; a workshop for equipment maintenance; a dam to store water for hydrostatic testing; and, borrow pits to source additional fill material if required.

WDS has brought in rock saws to deal with rock for trenching operations, and due to continuous wet weather, swamp dozers were used to clear the RoW in front of the welding crew.

Access tracks and additional gates have been constructed to access the pipeline easement and work areas, and existing roads, access tracks and disturbed areas have been utilised to minimise disturbance to the surrounding areas.

Installing compressors in Victoria: the Wollert Compressor Station upgrade

APA is also undertaking an upgrade of the Wollert Compressor Station, designed to expand capacity on the Wollert to Euroa Pipeline on the northern section of the Victorian Transmission System.

The Wollert Compressor Station upgrade involves the installation of two Solar Centaur 50 Low NOx emission gas turbine-driven compressors, fin fan after coolers, gas filters, and all associated services and piping. Construction commenced with earthworks in December 2009, with completion of the station piping and electrical systems upgrade scheduled in September 2010.

The two Centaur 50 compressors will supersede the existing three Saturn compressors. With each Centaur machine having more than five times the capacity – 6,102 horsepower each – of the older units, the station’s overall capacity will be increased by over three times. Provision has also been made for the installation of further compressors in the future.

3D modelling software was used to virtually assemble the project before construction. APA Manager Projects Victoria Tom Carroll said “The use of 3D modelling software has allowed for the entire project to be assembled in the virtual world before any construction began.

“The benefits of this technology were apparent from early in the design phase – allowing the end users to review the entire project easily and have their input – through to construction, with the minimisation of site work as a result of highly accurate design drawings,” he said.

The design of the Wollert Compressor Station was influenced by APA Asset Management and Engineering’s strategy to standardise designs nationally across all of APA’s future installations. Under the new strategy all compressor stations will be standardised across key deliverables, site layout, diverging plant configuration and equipment purchase.

Overall the project will involve the installation of 10 major equipment items, 20 km of instrument and electrical cable, 2.5 km of piping and 40 tonnes of structural steel. Approximately 10,000tonnes of reclaimed soil and 12,000 tonnes of imported select fill were used to complete site levelling.

Getting the right people for the job

The APA project team directly employed the services of six people in the core project team. Indirectly there were up to 20 personnel involved on the team with varying commitments depending on the deliverables on the schedule.

Mr Carroll said “Employing a competent mechanical and piping contractor under a lump sum contract and giving them the flexibility to manage the electrical contractor reduced the risk to APA and facilitates greater interdisciplinary co-operation.”

Keeping safe

Part of the design concept was to locate the new station in a greenfield site, outside the Wollert Compressor Station’s operating assets, thereby minimising the risk of construction personnel working in the vicinity of live plant. This had the combined benefit of allowing APA operations personnel to continue with their activities with minimal impact from construction personnel.

APA’s permit-to-work system was incorporated into the project, which included completing a job safety analysis for each job task prior to any work commencing. Weekly toolbox meetings are held with the contractors, co-ordinated by the project-specific safety officer, to ensure any site issues are addressed promptly and allowing a direct line of communication between the work crews and APA supervision.

Using local labour

For all construction activities, local labour was utilised and the majority of plant, materials and equipment has been procured from local suppliers. However, given the specialised nature of some equipment, some items and raw materials were sourced from outside Australia.

An example of equipment sourced or fabricated locally includes:

* Two filter separators; * Two filter coalescers; * Two air receiver vessels; * Two Venturi flow meters; * Two gas turbine exhaust silencers; and, * Electrical and instrumentation fit-out of the local control room.

The main piping contractor, Skinner Engineering, is located in Epping, approximately 15 km from Wollert, allowing for a greater degree of connectivity to the site.

Hanson also supplied the imported crushed rock from a local quarry, which meant that deliveries were timely and transport costs were reduced.

Environmental challenges

The geology of Wollert presented a risk as the site is founded on a thick layer of scattered basalt rock. The rock, in its natural form, does not form a good founding layer and so was required to be removed however this would leave the site requiring a lot of fill. A philosophy was adopted from the beginning of the project to minimise the underground services, which would reduce the scope of excavations.

In addition, there was an opportunity to reclaim and reuse the excavated rock for fill. As part of the earthworks contract a rock crusher was brought onsite to utilise much of the excavated material. “This resulted in an improved environmental outcome, a solid founding layer for the station and an overall reduced cost for fill,” said APA Senior Projects Engineer James Outteridge.

In addition, the findings of a flora and fauna site survey discovered that a rare and endangered moth, the Golden Sun Moth, was present in areas surveyed. It was determined that APA would not disturb the moth’s habitat or interrupt its breeding cycle.

“The environmental outcomes were achieved through a re-design of the station location and pipe route and by fitting the construction schedule around the moth’s mating season,” said Mr Outteridge.

It was possible for APA to meet the required actions following the development of the environmental impact study due to the early engagement of specialist resources to identify such issues, allowing the design team to maintain some flexibility in design and schedule.

Avoiding the hot tap challenge

Tie-in works were planned carefully to avoid any hot tap works, however a station shut down proved unavoidable. The shutdown plan required approval from multiple stakeholders prior to any work commencing on site.

Gas needed to be sourced from New South Wales to maintain the gas supply commitments and the opening of valves to ensure security of supply to the distribution companies. The works were completed early in 2010 before the higher demand for gas brought on by the colder months.