Cost Effective Development of a Remote Field: Installation of the Laminaria and Corallina Subsea Facilities
Authors: Murray Gordon , Thompson Roy , Ferrario Silvana 
Published: March 2009

Woodside Energy Ltd, together with its co-venturers BHP Petroleum and ShellDevelopment Australia, are developing the Laminaria and Corallina fields in Block AC/P8 of the Timor Sea, offshore northern Australia. The developmentconcept comprises a new-build FPSO supplied by six subsea wells, two manifoldsand a network of flowlines, umbilicals and risers. Water depths range from 380-420 metres across the fields, and all subsea facilities are designed fordiverless installation and operation. The two-phase installation campaigncommenced in September 1998 and the fields are due to commence operations in October 1999.

A particular challenge of the development is ther emoteness of the fields'location. Darwin, the closest shore support base, is some 550 km to thesouth-east, while the nearest existing oil fields are Jabiru and Elang, some170 km and 70 km distant. This remoteness has implications for the design ofthe subsea facilities in two key areas: firstly, installation must becost-effective, and secondly, maintenance and repair requirements must beminimised once the fields are in operation.

This paper describes how the challenges of the remote location were addressedand overcome during the installation of the Laminaria and Corallina subseafacilities, including the trees, manifolds, flowlines, umbilicals, risers and FPSO mooring system. In particular, the structuring of the installation programaround a single multi-functional support vessel from an early stage in thedesign process was a key factor in achieving efficient installation.

Introduction

In October 1996, Woodside Energy Limited (WEL) awarded the contract formanagement, design, procurement and installation of the Laminaria and Corallina Subsea Facilities to Coflexip Stena Kenny (CSK), an unincorporated Joint Venture between Coflexip Stena Offshore Asia Pacific Pty Ltd and J P Kenny Pty Ltd. Together with WEL, CSK set up an integrated team to tackle the challengespresented by this development. In particular the remoteness of the field, located in the Timor Sea, and the deep water of up to 420m, required innovativedevelopment and installation techniques.

At award of the Contract to CSK, selection of the installation support vessel(ISV) was made based on the installability of all components of the originallyproposed subsea field layout. The CSO Venturer, a construction classdynamically positioned monohull, was selected.

Field Development

The Laminaria and Corallina fields are located in a remote area of the Timor Sea, about 550 kilometres west-north-west of Darwin and 160 kilometres south ofthe Island of Timor, Indonesia, in exploration permit AC/P8 (territory of Ashmore and Cartier Islands) which is administered by the Northern territory Department of Mines and Energy on behalf of the Commonwealth of Australia. The Laminaria/Corallina development will be the first in this part of the Timor Sea, the nearest production facilities are the 'Jabiru Venture' located 170 kmsouth west of Laminaria, and Elang, some 70km distant in the zone ofcooperation (ZOC) between Australia and Indonesia, both operated by BHPPetroleum. The field location is shown in Figure 1.