The project’s offshore processing platform is located in 70 m of water, about 225 km from the WA coast, and has already marked a number of key construction milestones, including the installation of one of the world’s largest ever offshore platform installations in early 2015.
The 37,000 t topsides structure was shipped approximately 6,500 km from South Korea, before it was successfully floated over and set onto the steel structure.
18 high-rate, large bore development wells – eight at the Gorgon field and ten at the Jansz-lo field – will provide the initial resource for the Gorgon Project.
The Gorgon wells were originally drilled by the Atwood Osprey in 2012 and perforations campaign and final well operations completed by the Ocean America drill rig in late 2014, with the project’s subsea gas gathering system the largest ever installed in Australia.
More than 800 km of pipelines have been installed, including almost 200 km of main production pipelines, with the escarpment installation one of the most significant challenges in the upstream facilities scope, creating an unsupported span of some
270 m extending from the top of the continental shelf to the seabed in a water depth of around 750 m.
All offshore pipelines, including the corrosion resistant in-field pipelines, were installed in early 2014.
Meanwhile, all six onshore pipelines – three for each field – have been installed on Barrow Island, with the domestic gas plant tied in to the 1,539 km Dampier to Bunbury Natural Gas Pipeline.
The downstream section of Gorgon involves a three-train LNG facility and domestic gas plant, connected to the offshore facilities via a 12.5 km feed gas pipeline.
A total of 51 modules, weighing more than 200,000 t make up the main components of the trains, with the first module delivered in September 2012.
Five gas turbine generators will be used to power the LNG plant, with the capacity to provide 584 MW of electricity once operational.
The Kellogg joint venture group, a
KBR-led joint venture consisting of JGC, Clough and Hatch, was awarded the engineering, procurement and construction management (EPCM) contract for downstream and logistics on Gorgon in 2009, valued at approximately $2.7 billion.
CB&I was awarded the engineering, procurement, fabrication and construction (EPC) contract for the project’s LNG and condensate tanks, while a joint venture with Kentz was awarded a contract for the mechanical, electrical and instrumentation work on Gorgon in 2011, worth approximately $2.3 billion.
The Wheatstone Project’s downstream EPCM contractor, Bechtel, is overseeing the construction of two 4.45 MMt/a LNG trains, plus a 200 TJ/d domestic gas plant.
ENVIRONMENTAL INNOVATIONS KEY
In addition to Gorgon’s impressive scope, the project has been recognised for its efforts to maintain biosecurity integrity on Barrow Island, taking out the 2015 Biosecurity Awards Industry category for its Barrow Island Quarantine Management System (QMS).
The Barrow Island QMS is the world’s largest non-government quarantine initiative, and provides an unprecedented level of quarantine intervention across all operations, preventing the introduction of non-indigenous animals and plants that could potentially establish on the island, predate native species or compete with them for food, water and shelter.
“The Gorgon Project is being constructed on an island that has been designated a Class A Nature Reserve since 1910,” says Mr Barnett.
“While the strict quarantine provisions imposed on this project have posed some challenges, overall this project has demonstrated that large-scale resource activities can be balanced with a sensitive environment.”
In addition to the QMS, which was also recognised at the 2012 United Nations Association of Australia World Environment Awards, winning the Business Award for Best Practice Program, Gorgon’s carbon dioxide injection project is another significant innovation by Chevron.
In order to further minimise the project’s environmental footprint on the island, separated CO2 is injected into a deep reservoir unit, known as the Dupuy Formation, and more than 2 km beneath the island.
The process, which goes against standard industry practice, has been supported by both the WA and federal governments, providing it with post-closure indemnity.