Timor Sea

Timor Sea Oil and Gas Fields

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  • The Timor Sea is regarded as a highly prospective petroleum region.
  • Geological features are the Bonaparte (main) and Browse Basins.
  • The area is administered by the Northern Territory, Western Australia and the Timor Gap Joint Authority.
  • The Northern Territory Government administers the Ashmore Cartier Islands Adjacent Area (on behalf of the Commonwealth Government) and the NT Adjacent Area.
  • The Northern Territory is conveniently located close to the vast oil and gas resources of the Timor Sea. The Timor Sea is home to the world scale Bayu-Undan, Sunrise and Evans Shoal gas projects. Recently completed major oil developments include the Elang/Kakatua, Laminaria/Corallina and Buffalo projects. The Northern Territory, with abundant petroleum resources, is ideally positioned to be the next gas-based manufacturing hub for the region.
  • Exploration commitments offshore are high, with the expectation of further oil and gas discoveries in the future which would be stimulated by gas markets in Darwin and Australia.
  • Centrally located to Asian markets and a number of major resource projects in the Timor Sea and beyond, Darwin is rapidly developing into a service and supply hub for the region.


  • Exploration commenced in the early 1960s.
  • 32 wildcat wells (rank exploration wells) were drilled to 1975. There were several oil and gas strikes although no commercial developments resulted.
  • Exploration in the Timor Gap area was suspended in 1975 due to the unresolved border between Australia and Indonesia.
  • Signing of Timor Gap Zone of Cooperation Treaty and award of production sharing contract areas in 1992 hailed the start of the exploration ‘boom’.

Production and Exploration

  • There are currently 5 producing oilfields in the Timor Sea - Jabiru, Challis (both operated by Newfield Australia (Ashmore Cartier) Pty Ltd), Elang/Kakatua, (operated by Phillips Petroleum) Laminaria/Corallina (operated by Woodside Offshore Petroleum Pty Ltd) and Buffalo (operated by Nexen Petroleum Australia Pty Ltd).
  • In the Ashmore Cartier Islands Adjacent Area, Jabiru oil field commenced production in 1986, Challis/Cassini oil fields in 1989 and Skua oil field in 1991.
  • Production from the Skua field was completed during 1998.
  • In the Joint Petroleum Development Area (formerly Zone of Cooperation Area A), Elang/Kakatua/Kakatua North oil field began production in 1998. 
  • A number of projects are at various stages of feasibility and development: Bayu-Undan Greater Sunrise and Evans Shoal.
  • US$1.6 billion is committed for the Bayu-Undan liquids project, with production to commence in 2004.
  • There were 16 oil and gas discoveries in the past 5 years.
  • A$750 million is committed for Timor Sea exploration from 2001 to 2006.
  • Between A$7.75 to A$15.15 billion is proposed for potential developments of Timor Sea oil and gas resources.
  • Emerging technological advances may lead to commercial development of Prospective Fields.

Gas Projects

  • Estimated gas reserves of 566 billion cubic metres (20 trillion cubic feet) in the Bonaparte Basin, and 538 billion cubic metres (19 trillion cubic feet) in the Browse Basin off Western Australia, could meet the Territory’s current annual gas requirements for over 2,500 years.
  • Major fields being considered for development include:
  • On 23 February 2000, the Bayu-Undan project received approval for Phase 1 – Liquids Stripping from the Joint Authority for the Timor Gap Zone of Cooperation (now known as the Joint Petroleum Development Area). The field holds reserves of 64 million cubic metres (400 million barrels of condensate and LPG). Production is scheduled to commence in 2004, with peak production of 17,488 cubic metres (110,000 barrels) per day.
  • Woodside and Phillips announced on 30 November 2000 that they had reached in-principle agreement to pursue cooperative development of their Timor Sea gas resources in the Sunrise and Bayu-Undan projects. The concept is designed to combine the early gas delivery potential of the Bayu-Undan development with the large reserve base of the Greater Sunrise fields and to optimise investment in infrastructure.
  • Since the agreement however, Shell has announced a proposal for FLNG (Floating LNG) on Sunrise as an alternative to onshore LNG. The operator, Woodside, announced in February 2002 that FLNG is their preferred option. Should the Joint Venture partners proceed with this development option, there would not be cooperative development of the Bayu Undan and Sunrise fields.
  • In July, 2001 Phillips and its co-venturers announced the deferral of the subsea pipeline proposed to transport natural gas from the Bayu-Undan field to Darwin, Australia. This decision is due to unresolved legal, fiscal and taxation issues surrounding the development. However, Phillips and East Timor announced in December 2001 that an agreement has been reached on tax, legal and fiscal issues that will enable gas to be produced. The Agreement is subject to ratification by Australian and East Timorese governments and conclusion of a new Timor Sea Treaty. This is proceeding and is to be completed in time for East Timor's independence on 20 May 2002.
  • Phillips announced on 12 March 2002 that it has signed a Heads of Agreement (HOA) with The Tokyo Electric Power Company, Incorporated (TEPCO) and Tokyo Gas Co. Ltd (TG) detailing terms for the sale of three million tonnes per year of LNG from the Bayu-Undan field. Gas deliveries are expected to begin late 2005. This agreement commits nearly 100% of the proven reserves of this field. This HOA also justifies the initial pipeline infrastructure required to move Timor Sea gas into Australia.
  • Natural Gas Australia (NGA) has developed a concept to construct a high volume methanol and synfuels gas reforming facility on a concrete gravity structure located in shallow water adjacent to the Evans Shoal gas field. The first phase of the conceptual facility would have a production capability of 5,000 tonnes of methanol per day (1.725 Mtpa). The plant design would also incorporate a second phase of development, where production facilities could be expanded to 10,000 tonnes per day (3.45 Mtpa).

Oil Projects

  • Estimated remaining oil reserves in the Timor Sea are at least 167.73 million cubic metres (1.05 billion barrels) of oil, condensate and liquid petroleum gas (LPG).
  • Elang/Kakatua, developed at a cost of A$140 million is the first project to proceed in the area formerly known as ZOC-A. Production began in July 1998 via a floating production storage and offtake (FPSO) vessel, the Modec Venture 1. Design production capacity is 5,167 cubic metres (32,500 barrels) per day.
  • Woodside’s Laminaria/Corallina development, costing A$1.37 billion, commenced production from the Northern Endeavour, one of the world’s largest floating production facilities, on 6 November 1999. The production rate since start-up has averaged 142,500 barrels per day, with peak production rates of up to 180,000 barrels per day.
  • BHP Petroleum’s Buffalo development commenced production on 29 December 1999. The field has reached a net peak production of 20,000 barrels of oil per day.
  • Cumulative production to August 2000 at Jabiru was approximately 15.9 million cubic metres (100.2 million barrels) of oil and Challis/Cassini fields had produced 8.1 million cubic metres (51 million barrels) of oil. These fields are approaching the end of their productive lives.


  • Darwin is the logistics base for the majority of Timor Sea operations.
  • Supply vessels, helicopter support and other servicing facilities such as maintenance and rig refit capacity are available in Darwin.
  • Northern Territory receives 15% of exploration expenditure and 50% operational expenditure from Timor Sea projects - currently about $70 million per annum.
  • The new East Arm Port improves Darwin’s capacity to service offshore facilities.
  • Large volumes of gas onshore in Darwin could see the development of new industries and major investment in gas related projects such as liquefied natural gas (LNG), fertiliser, methanol and other gas based manufacturing projects.
  • There will be significant direct and indirect employment benefits for the Territory.

Current at  March 15, 2002

Director of Petroleum Development

Office of Territory Development
GPO Box 4396

Ph: 61 8 8999 5425
Fax: 61 8 8999 5191
email: otd.info@nt.gov.au