Julimar Development Project, Australia

The Julimar development project includes the development of the Julimar and Brunello natural gas fields. The two fields lie in the WA-356P exploration permit in the Carnarvon Basin, off the coast of Western Australia. Water depth in the permit area is up to 721ft.

Apache Corporation is the operator of the project and holds 65% interest. The remaining 35% interest is held by Kuwait Foreign Petroleum Exploration Company (KUFPEC).

Julimar and Brunello are the largest gas discoveries made by Apache. The partners in the project are expected to invest $4bn in the development of the two fields. First production is expected in 2016.

The natural gas produced from the fields will be supplied to the Wheatstone LNG Project being developed by Chevron in Western Australia.

Apache holds 13% interest in the Wheatstone project while KUFPEC holds 7% interest under an equity agreement signed in December 2010.

Discovery of the Julimar and Brunello natural gas fields

The Julimar field was discovered in April 2007 by the Julimar-1 well. Sedco 703 rig drilled the well to a depth of 12,221ft and encountered 132ft of gas column.

The Brunello field was discovered by the Brunello-1 well in September 2007.

Geology and reserves of the Carnarvon Basin

Julimar and Brunello field reservoirs are of the Triassic Mungaroo formation.

Combined recoverable gas reserves of the two fields are estimated to be in excess of 2.1 trillion cubic feet.

Drilling and exploration of the Australian coastal area

Three appraisal wells have been drilled at the Julimar field following the discovery. The Julimar East-1 appraisal well was drilled to a depth of 13,517ft and encountered 224ft of gas in six zones of the Triassic Mungaroo formation.

The Julimar Northwest-1 encountered 43ft of gas in the J-17 Triassic Mungaroo sandstone.

The third appraisal well, Julimar Southeast-1, discovered 195ft of gas in five zones in the Triassic Mungaroo reservoir.

Field development

FEED studies of the project commenced in May 2010. A preliminary development plan was submitted to the government in November 2010. The final development plan submitted to the government in May 2011 approved in August 2011. Apache took the final investment decision on the project in September 2011.

The development is phased out over 20 years. It involves drilling 20 subsea production wells in total. The drilling will be carried out from three drill hubs and two remote locations. The subsea wells will be connected to the Wheatstone platform.

The initial phase of the project will start with the development of the Brunello field as it is located closest to the Wheatstone platform.

Wheatstone central processing platform

The Wheatstone platform will be one of the biggest integrated production facilities in the world. It will feature topsides weighing 35,000t and a gravity based structure weighing 22,000t.

Each of the 20 wells of the subsea production system will be tied back to three eight-slot manifolds. The manifolds will be installed on the sea bed and connected through flowlines. Two raw gas production lines will connect the manifolds to the Wheatstone platform.

The gas recovered from the project will be mixed with gas produced by the Chevron-operated Wheatstone and Iago fields on the Wheatstone platform.

The gas will then be exported through a 225km subsea pipeline to the Wheatstone LNG facility near Onslow in Western Australia. The LNG facility will consist of two processing trains with an annual capacity of 8.9mt of LNG.

Contracts awarded

In May 2010 J P Kenny, part of Wood Group, was awarded the front end engineering and design (FEED) contract for the project. The scope of work includes FEED studies for the subsea development system. ASEEDA was subcontracted by J P Kenny for carrying out the FEED studies.

Mustang Engineering was involved in the review of carbon dioxide and nitrogen removal technologies suitable for use at the fields.

Atteris provided design services for shore approaches of pipelines for the project.