This is believed to be the first time that an AUV (autonomous underwater vehicle) of this type will be used to perform such an important and technically demanding survey in the offshore oil and gas industry in this region, Covus said.

Lying across the continental shelf, the Pluto Field is about 185km north-west of Dampier, Western Australia. The water depth at the Pluto field ranges from about 150m on the shelf edge to over 1100m to the north-west of the continental shelf.

Within the field, the seabed is characterised by several deep channels running off the shelf edge and steep slopes of up to 45 degrees or more are anticipated. This type of terrain and water depth has driven the requirement for an AUV survey rather than a more conventional survey.

Covus will perform this work in conjunction with Geoconsult AS of Norway, using the Hugin 3000-GC AUV. The vehicle will be deployed from the high-specification DP2 multi role support vessel 'Geosea'. This equipment will be brought from Norway specifically for the Pluto project.

The Hugin 3000-GC is a remotely controlled underwater vehicle that performs data collection in water depths down to 3000m.

Unlike industry standard ROVs (remotely operated vehicles), Hugin does not depend on an umbilical for power supply or instrument control. Its added freedom of movement means it is perfectly suited to detailed seabed mapping across a range of depths, or for operations where superior data quality and speed of collection is of primary concern.

The Hugin 3000-GC has a payload consisting of the best technology available on the market. The sensors are specifically designed for an AUV platform, meaning that a high degree of robustness has been included in the software and hardware, with a focus on low power consumption to increase operational endurance. The system also includes technology and software for real-time navigation and post- processed positioning.

Launched in 2002, the Geosea is a modern, high specification dynamically positioned Multi Role Support Vessel (MRSV) which has been purpose built for offshore construction and subsea intervention activities.

It has in-built 3,000m rated Triton MRV ROV and survey systems, a Super Puma-rated helideck, 30 tonne heave compensated crane, large working deck area (complete with moonpool) and accommodation for 70 personnel.

The Pluto project’s AUV survey campaign to start in Dampier at the end of this monthand is expected to last for several weeks.

At the completion of the Pluto geophysical survey, Covus and Geoconsult will make the Geosea and Hugin 3000-GC AUV available from Dampier for follow-on projects requiring AUV, ROV or diving operations.