Abadi Gas Field, Indonesia

The Abadi gas field is situated in the 3,221km² Masela block in the Arafura Sea, Indonesia. The field lies in water depths ranging 984ft-3,281ft.

Inpex Masela, a subsidiary of Japan-based oil and gas company Inpex, operates the field. Inpex earlier owned a 90% interest in the field but in July 2011 transferred 30% to Shell. Abadi is a large-scale project and Inpex invited Shell Upstream Overseas Services as a strategic partner to use its expertise in floating LNG technology. PT EMP Energi Indonesia owns the remaining 10%.

A product sharing agreement for the field was signed in November 1998, covering 30 years. The plan of development for the field was submitted in September 2008 to BPMigas, the Indonesian Government authority responsible for oil and gas upstream business, and approved in December 2010. First production is expected in 2018 with an initial output of 2.5 million tonnes of LNG a year and 13,000 barrels per day of condensate.

Discovery

A 2D seismic survey was carried out in the block using marine vessel Geco Rho between February and March 1999.

The Abadi field was discovered by the Abadi-1 exploration well, which was drilled between October and December 2000 by the Energy Searcher rig. The confirmed presence of gas and condensate was the first discovery of crude oil and natural gas in the Arafura Sea.

Between July and September 2001, a 3D seismic survey was carried out using the PGS Ramform Challenger marine vessel. In 2002, two appraisal wells, Abadi-2 and Abadi-3, were drilled to examine the extent of reserves of the field. Abadi-2 was drilled by the Energy Searcher rig and Abadi-3 was drilled by the Ocean General rig.

Four more wells drilled between May 2007 and June 2008 confirmed the presence of significant gas reserves.

Abadi geology and reserves

The Abadi field reservoir is of the Middle Jurassic Plover Formation and located at depths ranging between 3,700m and 3,900m. The reservoir contains shallow-marine, highly mature, quartzose sandstones.

The field is estimated to contain ten trillion cubic feet of natural gas reserves.

Field development

The field will be developed in phases using a subsea production system and a floating LNG facility. About 18 directional production wells are expected to be drilled from five subsea drilling centres. Initial development will be carried out in the northern part of the field, where most of the reserves are concentrated.

The produced natural gas will be processed, liquefied and stored for offloading in the floating LNG facility that will have annual production capacity of 2.5 million tonnes. The pre-FEED work for the floating LNG facility was carried out between September 2007 and November 2008. The FEED is scheduled to begin in the first half of 2012.

The project's environmental impact assessment is being carried out between 2010 and 2013, and the geophysical and geotechnical surveys in 2010 and 2011. FEED studies are scheduled for 2011-2012. The engineering, procurement and construction contracts are expected to be awarded between 2014 and 2018.

Floating LNG facility

The floating LNG facility will feature the integration of proven technologies such as FPSO, baseload onshore LNG plants and LNG carriers. It will include an LNG loading plant, an LNG storage tank and a loading facility similar to that available on a conventional FPSO.

The floating LNG concept was chosen for the field because it reduces the environmental impact of constructing an onshore facility in terms of the land, harbour and infrastructure facilities required.

The MetOcean conditions at the field also favoured the design and operation of the floating LNG facility. In addition, the concept is expected to reduce the costs incurred and the project lead time.

The project partners are expected to invest $19.6bn in the facility, which will be installed about 170km south-west of the city of Saumiaki.

Production

The feed gas produced will be collected through the subsea drilling centres and transported to the floating LNG through flexible production risers. The gas will be processed and liquefied on the floating LNG. The LNG and condensate will be stored in the floating LNG, and offloaded at regular intervals through LNG carriers.