From Offshore Technology web site

BAYU-UNDAN TIMOR SEA, AUSTRALIA

Bayu-Undan lies in the Timor Sea, 500km offshore of Darwin and 250km south of East Timor. It straddles the boundary between blocks 91-12 (60%) and 91-13 (40%), within Area A of the Australia/Indonesia Zone of Cooperation. The fields are located on the same 160km² structure.

DISCOVERY

Bayu was discovered in early 1995, when the Bayu-1 well intersected a 155m gas/condensate column, at a depth of 897m. This tested 2.54m³/day of gas and 5,250bbl of condensate. The follow-up well, Bayu-2, tested 991,000m³/day of gas and 2,000bbl of condensate from a 52m interval.

In July 1995, Undan was discovered 10km north-west of Bayu, where a 139m gross hydrocarbon column tested 1.6 million m³/day of gas and 3,900bbl condensate/day. The total recoverable field of reserves is 350-400 million barrels of hydrocarbon liquids and 3.4TCF of gas.

The 25x15km field will require approximately 26 wells over its lifetime to produce the reserves, 16 of which - including the first high-angle well in the Timor Sea - will be required before start-up. The field life is estimated to be 25 years. First liquid production is planned to commence in late 2003, with full commercial production by 2004. Preliminary engineering studies were completed in late 1998 and co-venturer approval was received in October 1999.

The project involves a two-phased development. The US$1.4 billion first-stage gas-recycling project will involve the production and processing of wet gas, the separation and storage of condensate, propane and butane, and the re-injection of dry natural gas back into the reservoir. Tankers will transport the product to market.

Total Integrated Group Approach (TIGA), an alliance between Fluor Daniel and Worley, was selected as the engineering and procurement contractor.

The development complex includes:

WELLHEAD (WH) PLATFORM

THE COMPRESSION, UTILITIES & QUARTERS (CUQ) PLATFORM AND THE DRILLING, PRODUCTION & PROCESSING (DPP) PLATFORM

These both consist of an 8-leg steel jacket, slotted to accommodate topside deck floatover. The jacket dimensions are 48x50m, with a height of 90m. The topsides are 54x64m and are 17.5m high.

The processing equipment includes three 23MW gas-turbine-driven injection compressors, two 7.5MW gas-turbine flash gas compressors and two turbo expanders. It has high-pressure (100/310bar) column vessels and four gas-turbine-driven generators. A Letter of Intent (LOI) has been issued to the Clough-Aker Joint venture for the floatover installation of the integrated topside.

FLOATING STORAGE & OFFLOADING FACILITY (FSO)

The purpose-built FSO, will be manufactured by Samsung Heavy Industries and permanently positioned offshore in the field. The vessel is expected to be completed by mid 2003. A Letter of Intent (LOI) has been issued to Advanced Production and Loading Systems for the supply of a mooring system to the facility.

PIPELINES

Flowlines between the DPP and FSO will consist of a 12in condensate line, a 6in carbon steel propane line, a 6in butane line and a 4in carbon-steel fuel gas line, all 2.3km long.

PHASE 2

A second phase of downstream development, to commercialise the field’s gas reserves, is also planned. Gas will be stored in a floating storage facility.