The Woodside-operated Blacktip field (covering the WA-279-P permit area) is the source for the Trans-Territory Pipeline. Discovered in August 2001, the field is approximately 100 km northwest of Port Keats in the Joseph Bonaparte Gulf.
Woodside estimates that there is scope for recovery of 1.1 trillion cubic feet of gas. The gas is expected to be of high nitrogen content which is consistent with most pipeline specifications in Australia.
The gas recovery development includes the construction of offshore production facilities which will be connected to a landbased processing plant at Wadeye Gate Station through a subsea pipeline.
The Heads of Agreement specified the proposed supply of 40 petajoules (PJ) of gas per annum over 20 years from 2007.
Alcan’s alumina refinery currently produces 1.85 million tonnes/year of Alumina and 2.0 million tonnes/year of Bauxite. The plant is currently undergoing an optimisation development where its production of Alumina will be increased to 2.1 million tonnes/year, with the first phase completed. The plant will then be expanded to 3.5 million tonnes/year capacity which requires about $A1.5 billion worth of investment. Approval for this expansion is expected by July 2004.
The final stage of this expansion will be the conversion to use natural gas as a fuel source as opposed to oil, which is expected to offer a long term stable energy supply to the Gove refinery. This stage will also include connection to the natural gas pipeline and is expected to cost about $A50 million.
The 940 km pipeline will stretch from Wadeye to Galupa running south of Katherine. It will be constructed with DN 400 or DN 450 API 5LX70 pipe rated at 900 # (15,300 kPa MAOP) at a total cost of $A500 million. There is the possibility for an intermediate compressor station at a location south of Katherine.
Currently a number of bidders have been short-listed to construct the pipeline ahead of a final decision. Procurement and materials supply and infrastructure upgrade is expected to be achieved by 2005 with pipeline construction beginning during the dry season in 2006. First gas production is scheduled for January 1 2007.
OSD Energy Services has supported the Trans-Territory Pipeline project by undertaking the corridor surveys and co-ordination of the field activities required to refine the pipeline’s route.
OSD involvement has included the initial pre-feasibility studies in July 2002, continuing into the current status of seeking pipeline licence approval under the direction of Alcan. OSD has supported Alcan as their pipeline engineering advisers throughout this period.
The activities OSD has performed are the engineering definition for the pipeline to assist with capital cost estimates, and the logistics and construction planning for the pipeline.
Major achievements have been:
- Route corridor refinement helicopter survey in July 03;
- Ground survey work to optimise the proposed pipeline centreline inside the corridor (currently in progress);
- Front end engineering design to define project to allow the submission to government to proceed (proceeding on schedule); and,
- Pipeline Sizing and Design Optimisation
OSD has also established a full GIS database management system for the project based on the Epic software packages. All field data is currently being gathered and lodged into the information management system.