Pluto LNG

Image Source : Enscope Projects – Pluto LNG Plant
Location : Burrup Peninsula, Karratha

Discovery of gas in the Pluto fields in the North West Shelf in April 2005, followed by discovery at the Xena field in September 2006, triggered the idea to monetise these resources by constructing the Burrup LNG Park. In July 2007, final approval was given to build a 4.3 MMTPA LNG plant, 190 km north-west of Karratha, in Western Australia. The 80-hectare facility is built on 200 hectares of leased land within the Burrup Industrial Estate, between the North West Shelf Venture gas plant and the Dampier Port. The joint venture between Woodside, Tokyo Gas and Kansai Electric signed 15-year sales agreements for majority of its capacity with its Japanese partners.

Design problems, labour shortages and construction quality issues pushed the original start date by 12 months and overshot the original budget by over two billion dollars. However, Pluto LNG was still acclaimed as one of the fastest developed LNG plants of its time, from gas discovery in 2005 to first LNG production in 2012. The LNG train has a pre-assembled and modularized design concept, which extends across the plant, with almost 320 modules assembled primarily in Thailand.1 The facility is capable of expanding to a total of 5 trains and handling third party gas for processing. By April 2018, Pluto had already dispatched its 400th cargo. In October 2018, Bechtel was selected as FEED contractor for a proposed expansion plan, which may witness FID as early as 2020.2

Over 15,000 Australian construction jobs were created by the project, which claims to have delivered in excess of A$7.6 billion in local content.3 Woodside also supports its community by funding three categories – philanthropy, shared value and collective impact. The company has pledged up to A$100m for an initiative to offset reservoir emissions from the Pluto field, which could potentially brand Pluto as one of the most environmentally efficient LNG plants in the world. The project also works with the largest marine monitoring programme of its kind in the world and has committed to offset its impact to the marine environment through a biodiversity offset programme.

OWNERSHIP (Equity %)

Woodside Energy 90.00%
Kansai Electric 5.00%
Tokyo Gas 5.00%

General Data

Estimated Capital Cost (USD)12 B
Plant TypeOnshore Modular
Plant StageOperating
Final Investment Decision (FID) Year2007
FEED ContractorFoster Wheeler (now Wood Group)
EPC ContractorFoster Wheeler (now Wood Group)
Worley Parsons
No. of Trains / capacity1 Train / 4.43 MMTPA
Production Start Year2012
ProductsLNG,Condensate
Gas TypeNon-associated Gas (NAG)

Technical Data

Cooling Media Air
Liquefaction Technology Shell Propane precooled / Mixed Refrigerant (C3/MR)
Refrigeration Train Details:
Propane String
Driver GE MS7121EA DLN1 (Frame 7EA)
Heavy Duty Gas Turbine
Propane Compressor 3MCL1405
GE (Nuovo Pignone)
Horizontally Split Centrifugal Compressor
Starter/Helper Motor ABB 20 MW Synchronous Motor with ABB LCI Drive
Mixed Refrigerant (MR) String
Driver GE MS7121EA DLN1 (Frame 7EA)
Heavy Duty Gas Turbine
Low Pressure (LP) MR Compressor AN250
GE (Nuovo Pignone)
Axial Compressor
Medium Pressure (MP) / High Pressure (HP) MR Compressor 2BCL806
GE (Nuovo Pignone)
Radially Split Centrifugal Compressor
Starter/Helper Motor ABB 20 MW Synchronous Motor with ABB LCI Drive
Power Generation Qty: 4
GE PG6581B (Frame 6B)
Heavy Duty Gas Turbines

Refrigeration Train Configuration

Key Facts

  • The Pluto LNG design is based on the North West Shelf (NWS) Trains 4 and 5 design and utilizes the Shell Propane/Mixed Refrigerant liquefaction process with two Frame 7EA gas turbine drivers. A significant difference that the Pluto LNG design had to account for was higher nitrogen content in the feed gas with leaner hydrocarbons when compared with NWS.4
  • The high nitrogen content in the feed gas required the addition of a nitrogen rejection unit (NRU). The NRU is installed in the fuel gas system to reduce the Nitrogen content to within the specification of the gas turbines. The Frame 7EA gas turbines driving the refrigeration compressors are designed for up to 40mol% Nitrogen in the fuel gas whereas the Frame 6B gas turbine generators can handle up to 15mol% Nitrogen.4
  • The higher nitrogen content also resulted in the need to re-wheel the end flash gas compressor. Debottlenecking of the end flash gas system is expected to have increased LNG production by 3-4%.4
  • Due to the AN-200 axial compressor (LP MR) failures experienced on NWS Trains 4 & 5, Pluto LNG was built with the AN-250 which has a larger flow capacity, higher efficiency and a more robust mechanical design compared with the AN-200.4
  • For Pluto LNG, a new Propane compressor casing and impeller design was developed. At the time, the propane compressor was one of the largest in terms of power (almost 80MW in a single casing) and flow capability (640 kg/s) for its size. The first stage impeller was at the edge of GE Oil & Gas’ experience with a peripheral (or machine) Mach number of 1.2 and an inlet relative Mach number of 0.975 (compared to 0.92 for NWS Trains 4/5).4
  • Pluto LNG was scheduled to be on stream by 2010 but it started producing from 2012 due to several delays. This also affected the budget of the project which post FID increased from A$12 billion to almost A$15 billion.5
  • Some of the issues that contributed to start-up delays at Pluto LNG include:9> The flare towers needed replacement as they were not adequately designed for the high wind loading during cyclonic conditions at site.> Issues with the onshore MEG system and effluent treatment plant (ETP)
  • At Pluto LNG, Woodside pioneered a new “Once through MR” process for the on-site production of refrigerant quality Ethane. The process involves bleeding natural gas into the mixed refrigerant (MR) circuit whilst operating the MR compressors to circulate the gases through the refrigerant circuit. Continuous introduction of natural gas and removal of light components results in an increase in the composition of heavy components in the circuit and eventually the generation of significant quantities of ethane rich liquid refrigerant. Using this method sufficient mixed refrigerant for a train start-up and ramp-up to 70% was made within two days, which was a significant improvement over traditional approaches for ethane generation. Some years later, this method was successfully employed by Yemen LNG on an APCI process to generate ethane when it was shutdown due to geopolitical issues.9,10,11
  • In March 2015, production was shut down for six days as part of precautionary action when Atwood Ospray, a submersible drilling rig, owned by Atwood Oceanics parted several mooring lines and drifted approximately 3 nautical miles from its original position during Cyclone Olwyn.12
  • The Pluto LNG export plant produced 5 MMTPA during 2016, 16% above its original design capacity of 4.3MMTPA.14
  • Pluto LNG Project won the Sir William Hudson Award at the National Engineering Excellence Awards in November 2012 for its proactive efforts in environmental management in areas like Dredge Disposal Management, Sea Turtle Management, and Greenhouse Gas Abatement.7

Source:

1. ‘Foster Wheeler Projects: Pluto LNG’, Amec Foster Wheeler Website, 13 May 2012
2. Milne P. ‘Woodside picks Bechtel for second train in Pluto LNG expansion’, The West Australian Website, 9 October 2018
3. ‘Pluto begins LNG Production’, Woodside Energy Website, 30 April 2012
4. Pelagotti A. et al ‘Pluto LNG – LNG optimization using existing plant experience’, LNG 16 Conference Oran, Algeria, April 2010
5. Forster C. ‘Australian LNG – Busting the Budget’, S&P Global Platts Website, October 2013
6. ‘Pluto Liquefied Natural Gas (LNG) Project, Northern Carnarvon Basin’, Hydrocarbons Technology Website
7. ‘Pluto LNG Project – Five Year Performance Review Report’, Woodside Energy Website, December 2012
8. Economics and Industry Standing Committee ‘The economic impact of floating LNG on Western Australia Volume 1, Legislative Assembly, Parliament of Western Australia, May 2014
9. Ransom G. ‘Pluto LNG Plant start‐up’,17th International Conference & Exhibition on Liquefied Natural Gas, Houston, 17 April 2013
10. Hodges D.W. ‘Production of ethane for start-up of an LNG train’, Google Patents Website, 2013
11. ‘The Yemen LNG teams successfully produce ethane despite production shutdown’, Total Website
12. ‘Drifting rig shuts Pluto LNG production’, LNG World News Website, 16 March 2015
13. ‘Trafigura grabs Pluto LNG spot cargo’, LNG World News Website, 2 July 2015
14. Stewart R.M. ‘Woodside Plans to Expand Western Australia LNG Output’, The Wall Street Journal Website, 21 February 2017