In March 2015, AGIG started commercial operation of the Fortescue River Gas Pipeline. The 16-inch pipeline runs 270 kilometres east from the Dampier to Bunbury Natural Gas Pipeline (DBNGP) Compressor Station 1, to the 125MW Solomon power station which services the Solomon Hub iron ore mine, owned and operated by Fortescue.
Fortescue is the foundation shipper under a 20-year, 100% take-or-pay contract. The pipeline is owned by a Joint Venture (AGIG at 57%, TransAlta at 43%), with AGIG as the pipeline operator.
Survey of pipeline route
Part of the project Front End Engineering Design (FEED) studies included walking the pipeline route to de-risk the construction process. The survey was completed in consultation with traditional owners and pastoral landowners to minimise disruption and impacts.
One of the biggest construction risks of the Fortescue River Gas Pipeline was rocky terrain, often slowing construction progress to a crawl, and required specialist rock breaking equipment. Walking the route and pot-holing key sections allowed AGIG to provide a lower and more accurate construction cost to Fortescue.
Detailed engineering and design
This was undertaken by our in-house engineering and pipeline design team from late 2013. The project scope included pipeline design calculations and three associated facilities including the inlet meter station adjacent to DBNGP, the mid-point scraper station (pig launcher and receiver) and the custody transfer meter station and customer delivery facilities at the Solomon power station.
Heritage, environmental and land management approvals
Our in-house land management team negotiated three agreements with the Kuruma Marthudunera and Yindijibarndi People. Extensive cultural heritage surveys were undertaken across the pipeline route to ensure that sensitive areas were protected and avoided during construction and operation. The agreements were achieved in six months and established long-term, sustainable relationships with the traditional owners of the land.
Our in-house team of lawyers and land access professionals negotiated land access and compensation agreements with the five pastoral properties traversed by the pipeline. Numerous mining tenement holders were consulted and agreements reached on access to land, rail crossing, road crossings and power line crossings along the route. We worked with stakeholders to minimise disruption to their activities, while providing income-generating opportunities as a value add component of the construction process.
Both State and Federal environmental approvals were managed in-house, utilising industry expert resources, to provide a sustainable environmental statement in relation to project impact. The project was also offered lead agency support from the Department of State Development in March 2014, who supported AGIG in coordinating applications for statutory and regulatory approvals.
All environmental, regulatory and statutory approvals were completed within 12 months, allowing the project to commence during spring 2014.
The pipeline licence application process was managed with the Department of Mines, Industry Regulation and Safety using in-house expertise. Subsequent approval stages involved consent to construct, operate and commission, also managed through the same technical approvals team. Other key approvals included the development of a Safety Case acceptable to the regulators.
Our in-house Contracts and Procurement team lead the undertaking of the contracts processes in an efficient, cost effective, confidential and ethical manner to deliver the best outcomes for Fortescue.
Following quotations from multiple suppliers, we undertook a technical and commercial bid evaluation process, then negotiated final terms and conditions before awarding the contract to the selected suppliers.
The major long-lead contracts for the pipeline included:
• Line-pipe Supply
• Pipeline Construction
• Valves and Major Equipment Package
Construction and Commissioning
The construction team began by installing pipeline markers along the easement and moving fencing where necessary. This preceded the clear and grade team who operated bulldozers, excavators and graders to create the right-of-way (ROW). The vegetation and top-soil were removed (to be reinstated at the end of the project). The stringing crew then trucked the line pipe from the Nickol Bay stockyard, located near Karratha, to the ROW. Excavators lifted the line pipe onto the ROW from the trucks with specialist vacuum lifts. Certain sections also required a bending crew to match the pipeline to the undulating terrain.
The welding and non-destructive testing crew followed. This is the most labour intensive work group with enough resourcing to move at speeds around 1-2 km/day. The coating crew then cleans and wraps the welds with non-corrosive materials to ensure pipeline integrity is maintained. The trenching crew quickly followed and dug to the specified depth of cover. To improve project safety and environmental protection, the trenches are left open for as little time as possible, hence the lowering-in crew closely follows the trenching crew. Multiple side booms are used to carefully lift the pipe into the ditch with padding and backfill crews following closely behind to cover the trench as soon as possible.
The last critical test prior to commissioning is hydrostatic testing. This process involves filling sections of the pipeline with water and compressing to 125% of the maximum operating pressure. Following the hydrostatic testing the ROW is reinstated in readiness for operations. At the time of its construction, the Fortescue River Gas Pipeline was the longest gas pipeline built in Western Australia during the previous 10 years.
The construction was delivered through rocky terrain in challenging Pilbara conditions. AGIG together with the pipeline constructors managed wet weather, extreme temperatures, and challenging ground conditions to deliver the project without any safety incidents, on schedule and within budget.
Post construction, the commissioning team mobilised – with mechanical and electrical checks of safety valves, metering systems and checking the Supervisory Control And Data Acquisition (SCADA) remote communications are correctly transmitting data to the AGIG control room. Once checks were signed off and regulatory approval granted, the pipeline was purged with nitrogen to remove air in the line before introducing natural gas. The system pressure was incrementally increased with system checks at each megapascal (MPa) of pressure.
Once the pipeline passed all commissioning checks, the system was handed over to operations in the electronic asset management system. This ensured the Asset Management Plan and associated processes developed by the in-house technical and operations teams were functional for operations. Based on these processes, the operations team will undertake preventative and corrective maintenance for the entire life of the Fortescue River Gas Pipeline.
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