The Santos Gladstone LNG (GLNG) Project involves the development of gas fields in the Bowen and Surat basins in south-west Queensland, the construction of a 420 km underground gas transmission pipeline to Gladstone, and a two-train LNG processing facility with a combined capacity of 7.8 MMt/a on Curtis Island.
Santos GLNG is responsible for the construction and operation of the project, and is working with several key contractors to deliver major components.
Fluor is working with Santos GLNG to construct three gas compression hubs, Saipem Australia is constructing the underground gas transmission pipeline, and Bechtel is constructing the LNG Plant on Curtis Island, off the coast of Gladstone.
The project has an estimated gross capital cost of $US18.5 billion from the final investment decision made in January 2011 to the end of 2015, when the second train is expected to be ready for start-up, based on foreign exchange rates which are consistent with the assumptions used at FID (A$/US$ 0.87 average over 2011-15).
Santos has a 30 per cent interest in the project, along with PETRONAS which holds a 27.5 per cent interest, Total which holds a 27.5 per cent interest, and KOGAS which holds a 15 per cent interest.
All pipe for the construction of the 420 km pipeline is in the ground, and reinstatement is complete on 85 per cent of the pipeline route.
Pre-commissioning is well underway, with 85 per cent of clean and gauge activities successfully completed, and 48 per cent of the pipeline hydrotested as of May 2014.
A Santos GLNG spokesperson told Gas Today “This year is about delivering milestones across the business, as we lead the efforts in making Queensland a world-leading gas producer.”?
The GLNG Project is scheduled to start up in 2015 and once ramped up, together with PNG LNG, Santos will hold more than 3 MMt of equity LNG. With such results, Santos should inspire confidence that Australia not only has the knowledge, but the capability to deliver successful LNG projects.
Pipeline tunnel success
A major milestone was celebrated in May 2014 when the final section of the GLNG gas transmission pipeline was successfully pushed through a tunnel beneath the Gladstone Harbour to the LNG plant on Curtis Island, Queensland.
The 120 pipeline segments, each measuring 36 m, were welded and pushed through the 4.3 km tunnel using a large hydraulic jack, as the tunnel filled with seawater to buoy the 42 inch diameter pipeline.
Santos Vice President Downstream GLNG Rod Duke said the delivery of the first under-sea crossing for Queensland’s CSG-to-LNG industry brings the pipeline to its final stages of completion.
“In the coming weeks the marine crossing pipe will be connected to the rest of Santos GLNG’s 420 km pipeline, already buried on the mainland and Curtis Island,”? Mr Duke said.
“This year is about delivering milestones across Santos GLNG, and we’re particularly proud of this achievement given the innovation and expertise required to achieve a marine crossing like this one.
“Our under-sea tunnel has allowed us to cross The Narrows without disturbing the local marine environment, and with minimal impact to the surrounding coastal environments.”?
The 3.45 m internal diameter undersea tunnel was a feat in itself, running approximately eight metres below the sea bed and constructed using a 100 m long, 277 t tunnel boring machine.
Success in the fields
During the first quarter of 2014, and in line with the 2014 drilling plan, 35 wells were spud in the GLNG acreage, which included 24 development wells (19 at Fairview, five at Roma) and 11 appraisal wells.
The deliverability of existing wells in Fairview continues to exceed expectations, with a current average optimum gas rate of 1.9 TJ/d per well from the 171 current producing wells.
The Roma field continues to perform in line with expectations, with 50 wells on line and dewatering of the field underway.
Trains nearing completion
Construction of the LNG facilities on Curtis Island is progressing well, and all of the 82 Train 1 modules have now been delivered to the site and are in place.
Seven of the 29 Train 2 modules have also been delivered to site, and construction is underway on all of the remaining Train 2 modules.
Module connections, piping fit-up and welding, and cable pulling are progressing, and the gas flare stacks raised into position.
Three of the five inner nickel steel tank-shell rings for Tank B have been installed, and installation of internal instrumentation piping has commenced.
Work also continues on Tank A, with two of the five nickel steel tank shell rings installed.
The jetty is over 95 per cent complete, with the installation of quick-release mooring hooks and fenders complete, and installation of the gangway tower and pre-commissioning works commenced.
The GLNG control room was connected to Santos’ Brisbane headquarters in May 2014, which enables final testing and commissioning to begin at Santos GLNG’s largest gas compression hub.
This milestone marks the handover of the hub from the construction contractor, Fluor, to Santos GLNG, and brings it closer to start-up and gas production.
Santos Vice President Queensland Trevor Brown said new work fronts would open up at the hub in Fairview field, two hours’ drive north of Roma, now that the connection was complete.
“Now that our hub control room is connected to the Brisbane operations centre we can monitor the status of all equipment at this site and eventually control the hub from hundreds of kilometres away,”? Mr Brown said.
“Our Brisbane-based personnel can receive real-time data about gas production and view live-stream footage once CCTV cameras are installed at the site.
“The connection is the culmination of four weeks of hard work involving the installation of power supplies, testing fibre optic networks, energising our systems and loading new software.”?
Three hubs under construction for Santos GLNG include one in Roma and two in Fairview field.
From 2015, the hubs will compress and treat gas extracted from nearby wells so it can be sent along the pipeline to Gladstone for conversion to LNG for export.