Fugro Uses AUV on Akpo Field

Fugro Survey Ltd, UK, is using conventional ship-borne techniques as well as an autonomous underwater vehicle for a major seabed survey contract off Nigeria.

The surveys are for Total Upstream Nigeria to support the deepwater Akpo field development. Engineering survey data is being gathered to determine the optimum pipeline route to connect the deepwater (over 1400m) field to an existing shallow water pipeline system closer to shore.

For the deepwater section of the work, Fugro's survey vessel Geo Prospector is deploying the NUI Explorer AUV. This operates to depths of 1500m to acquire deepwater high resolution survey data in a far more cost-effective way than by conventional ship-borne towed systems. With a typical constant survey speed of four knots the AUV can survey over 100 survey line-kilometers on each dive, with a typical 24-hour duty cycle.

Fugro Survey mobilized the NUI Explorer vehicle in Bergen, Norway, after extensive deepwater trials which drew on Fugro's experience with its own AUV - Echo Ranger - currently engaged on deepwater projects in the Gulf of Mexico.

On Akpo, NUI Explorer acquires simultaneous data on:

  • Bathymetry. High accuracy depth measurements using Simrad EM 3000 or EM 2000 multibeam sounder and DigiQuartz pressure sensor;
  • Seismic. Shallow penetration data using a sub-bottom profiler;
  • Seabed imagery. Dual frequency (100/400kHz) sidescan sonar.

For the shallow water section of the route Geo Prospector uses conventional vessel-mounted and towed systems. Onboard data processing gives the client the opportunity to make a near real-time assessment of the pipeline route. caption: Fugro Survey is using the NUI Explorer AUV for deepwater pipeline route surveys off Nigeria.