Project Profile
Location: Barrow Islands, off the Pilbara coast, 85 Kilometers north – north – east of Onslow and 140 Kilometres west of Karratha
Gorgon main project:
The projects will see the proposed establishment of a midstream development, which will includes an LNG facility on Barrow Island, which lies directly between the gas fields and the mainland. The LNG plant will have three trains, with a nominal capacity of 5 million tonnes per annum each (Train 1 due online 2014). The LNG plant can only be 300 hectares big under the 2003 Barrow Island Act. The joint venture partners have letters of understanding for the long-term supply of up to 4 million tonnes of LNG per annum to North American West Coast. There will also be a domestic gas plant, with a capacity of 256 MMcf/d (300TJ/d) is part of the project.
The CO2 re-injection scheme would transport produced CO2 from the Gorgon field and re-inject it into the Dupuy reservoir 2,500m below Barrow Island. If successful, the intended technology would reduce the LNG project’s CO2 emissions from 9.5 million tonnes per year to 3.5 million tonnes per year.
The Gorgon reservoir has 12.9tcf of gas in a water depth of 220m. It is also high in CO2 (in the 10-15% range) and is HT/HP (130 degrees c/360 bar). The Jansz Reservoir is lean with low co2 (1%) and is located in 1350m of water. There are plans to increase the capacity of the trains to 7/8 mtpa.
The Final Investment Decision was approved on 14 September 2009.
Site Preparation and Temporary Construction Facilities scope:
Value: $505 m
Thiess is responsible for the bulk earthworks for the LNG Plant site and associated areas, selective earth and rock materials processing, Material Off-loading Facility (MOF), consisting of: causeway and breakwater construction, drainage construction, miscellaneous concrete and road works, installation of transportable buildings, supply and installation of all supporting services and utilities as well as the design and installation of steel framed buildings.
Project Delivery
Commencing in February 2010:
Preliminaries, including mobilisation and site establishment, quarantine, survey and demobilisation (Value $155M)
Plant and Administration Areas (Value $104M)
Construction and installation of temporary construction facilities (Value $34M)
Design and construction of steel framed buildings (Value $23M)
Drilling and blasting of insitu limestone rock (Value $18M)
Installation of utilities such as potable water, wastewater, electrical and communications infrastructure (Value $40M)
Construction of the Materials Offloading Facility Causeway in two stages (Value $33M)
Processing of blasted rock to produce:
Concrete and asphalt aggregate
Road materials
Trench backfill material
Bund material for the MOF
General and structural fill materials (Value $60M)
Earthworks and the construction of roads and drainage for the LNG
Provisional Sum Buildings (Value $38M)
Quarantine & Logistics
Given the offshore location of Barrow Island, most plant and materials will be transported from Perth to the Dampier Supply Base from where it will be loaded onto a barge and shipped to the island. As Barrow Island is an internationally significant nature reserve, quarantine management is necessary to prevent the introduction of non-indigenous flora and fauna.
Operators:
Chevron Australia – 47% interest
Shell– 25% interest
ExxonMobil – 25% interest
Osaka Gas – 1.25% interest
Tokyo Gas – 1% interest
CHUBU Electric Power Co – 0.417%
Contractor:
The Kellogg Joint Venture:
Kellogg Brown and Root
Clough
Hatch
JGC
(The Kellogg Joint Venture has awarded Thiess the contract on behalf of Chevron; so Thiess will act as main contractor for this scope of work)
Thiess
Sub Contractor:
Complete Steel Projects Pty Ltd.: Cladding Works and Structural Steel
Decmil Group Limited: Temporary construction facilities