Chevron Corporation's (Chevron) Gorgon gas development project on the Barrow Island has received final environmental approval from Western Australia's Environment Minister Donna Faragher. The ministry approved the revised and expanded project with new environmental conditions offering higher levels of protection for regionally significant coral reefs and flatback marine turtles.
The project was approved after consulting the State Development, Mines and Petroleum and Lands Ministers as required under the Environmental Protection Act 1986.
The environmental conditions governing the project ensure:
— that coral lost due to dredging will continue to be confined to 3% of the total coral area off the east coast of Barrow Island
— that monitoring is extended to significant coral reef outcrops outside impact zones
— artificial light emissions will be minimized to protect the local population of flatback marine turtles
— an extension of the turtle conservation program from 30 years to the total life of the project
— noise emissions to be incorporated into the long-term marine turtle management plan and other plans as required
— Requirement for the proponent to continue monitoring for subterranean fauna.
— It is the first time that management of light emissions has been required as a project condition.
Chevron, with a 50% interest, is the operator of the development on behalf of the Gorgon Venture partners. Other partners are Exxon Mobil Corporation (ExxonMobil) and Royal Dutch Shell plc (Shell) each holding 25% interest.
The joint venture partners of the Gorgon project have already secured LNG buyers for Gorgon LNG project.
Recently, Petronet LNG Ltd. entered into a purchase agreement with ExxonMobil for supply of 1.5 million metric tons a year of LNG from Gorgon project for 20 years.
Earlier in June 2009, Chevron signed non-binding heads of agreements with three utility companies in Japan and GS Caltex in South Korea for approximately 70% of LNG supply from the Gorgon LNG project.
In September 2007, Shell Eastern LNG and PetroChina International Company Limited have inked a binding heads of agreement for the long-term supply of liquefied natural gas (LNG) with the primary source being the Gorgon project in Western Australia.
Gorgon project involves the development of Greater Gorgon gas fields in the Carnarvon Basin located about 130 km off the northwest coast of Western Australia and construction of a LNG plant on Barrow Island. The Greater Gorgon area incorporates a number of gas fields in waters ranging from 722 to 4,265 feet.
Upstream development plans for Greater Gorgon include subsea completions for both the Gorgon and Jansz fields. Up to 30 subsea wells will be drilled on the Gorgon and Jansz fields during their production lives.
The development proposal includes the construction of a gas processing facility on Barrow Island consisting of three 5-million tonnes per-annum (mtpa) LNG trains and carbon dioxide injection facilities and a domestic gas phase of up to 300 terajoules per day (TJ/d). Initially, the project was approved for two 5-mtpa train development but later it was revised to include one more 5-mtpa train. The third train will be built within the 300-hectare development site allocated in the Barrow Island Act, representing just 1.3% of Barrow Island.
Subsea development of the Gorgon and Jansz gas fields involves subsea pipelines from the fields to Barrow Island. The project also includes the development of LNG shipping facilities to transport products to international markets.
Subsea development on the Gorgon field includes two production centers in the first phase. One center will accommodate six subsea wells, and the other will be able to accommodate four subsea wells. A 6-kilometer infield flowline will be constructed to connect the two production centers. Development on the Jansz field includes one production center that will be able to accommodate up to six subsea wells.
The process system will receive hydrocarbons from the Greater Gorgon gas fields and produce LNG for export, with the ability for domestic gas to be fed into the existing mainland distribution network.
The upstream wellhead collection facilities from the Greater Gorgon Gas fields will be situated approximately 90 km west of Barrow Island.
The process facility is being designed to produce 15 mtpa of LNG and 300 terajoule-per-day (TJ/d) of domestic gas (DOMGAS) per day. Carbon dioxide from the incoming gas stream will be stripped out in the process facility and compressed for reinjection into saline aquifers deep beneath Barrow Island.
The Kellogg Joint Venture–Gorgon (KJV), which comprises Hatch, Kellogg Brown and Root, JGC Corporation of Japan and Clough Projects Australia, will perform pre-front-end engineering-design (FEED) work for the downstream elements of the Gorgon project comprising three, 5 mtpa LNG trains and a 300 TJ/d DOMGAS plant.
It may be recalled that in October 2007, the Federal Minister for the Environment had issued Australian government approval for the Gorgon Development Proposal on Barrow Island.
The Greater Gorgon gas fields (Gorgon and Jansz), discovered in 1981, is Australia’s largest gas resource and has certified gas reserves of over 40 trillion cubic feet with a nominal development life of around 60 years. The Gorgon project will result in 45 million metric tons per annum less greenhouse gases compared to the use of more carbon intensive fossil fuels to supply energy to Asian markets.