Vessels in Good Order

The Norwegian company Eidesvik runs a modern fleet of highly specialized vessels, a number of which operate in the seismic survey sector. Their longtime business partner CGG is a fully integrated geoscience company operating out of 70 locations worldwide.

For three years now, their joint venture, CGG Eidesvik Ship Management AS, has operated and managed the high-end seismic vessels in the CGG fleet. This venture was created to share the constraints of seismic operations and achieve excellence through reduced maritime downtime, better targeted maintenance and improved information flow.

The ship management joint venture operates ten vessels, one of which is the Oceanic Endeavour. This is a dual-source, multi-streamer seismic vessel equipped with state-of-the-art integrated geophysical and navigation data acquisition systems.

The seismic sources on the vessel consist of tuned arrays of air guns. Three NEA Seismic Air Power Systems (NEA SAPS) of the 62 series serve as energy sources for the air guns. They provide air pressure of up to 200 bar (3,000 psi) with a screw compressor and a three-stage, two-cylinder V-type NEA reciprocating compressor.

Competent and flexible on board

Once a year, NEAC Compressor Service carries out maintenance work on the containerized compressor systems. The technicians inspect and replace wear parts if necessary. To keep downtime to a minimum, the three-year revision and subsequently the one-year service were scheduled during a dry dock overhaul in Måløy, Norway.

To save time, the supervisors boarded the ship there before their colleagues joined them in Måløy. The NEAC supervisors started with the first dismantling work during the transfer, in consideration of the tight time schedule of two weeks.

Coordinating their work was particularly challenging for the service technicians. As usual on a ship, resources such as cranes, tools, mounting equipment or hoisting devices are always limited. Nevertheless, the six NEAC experts disassembled all recip compressor wear parts (apart from such crankcase driven components as the cross head or connecting rod), and replaced them with new ones, where necessary. They also exchanged the frame tie-rods with newly designed and improved ones.

After this they replaced the three screw compressors with new couplings, coupling bolts and alignment and the existing condensate system also had to be renewed. In addition NEAC checked and cleaned all other important parts to ensure proper and even better functioning of the complete unit.

NEAC Product Manager Stefan Damberg was surprised: “During overhaul and measuring almost all replacement components showed no, or only little wear and were in remarkably good condition.”

For the next 4,000 operating hours, the Oceanic Endeavour is now perfectly prepared for superior 3D high-resolution and 4D seismic projects; in accordance with its leitmotif: safer, quieter, better offshore acquisition.