DNV to Class Two Ramform Series Seismic Vessels (Japan)

The new, fifth generation Ramform series seismic vessels of PGS is built at Mitsubishi Heavy Industries Ltd., Japan. The order for two seismic vessels plus two options which was signed in Oslo earlier this year. When completed in 2013 these vessels will be the most technically advanced seismic vessel featuring 3D seismic data acquisition and analysis capability. The vessels will be built to DNV class.

The new seismic vessels are the first in fifth generation Ramform series, “Ramform W-class”. Developed to have length of 104 meter and a very wide breadth of 70 meter, the series adopted diesel electric for the main propulsion system for quiet operation. Based on the design of the current Ramform fleet, capabilities along several key parameters were improved.

“These new generation series are developed in much bigger size compared to the previous Ramform series. One of the main reasons to develop the new Ramform design in wider hull form was to increase the stability and results of PGS’s model tests on these new hull shape prove that these new design give better stability compared to the previous Ramform series,” elaborates Johan Tutturen, DNV Country Manager, Japan.

The advanced seismic technology applied to these vessels are targeted for the fast growing High Density segments which are driven by deep water exploration and production in geologically complex areas such as Brazil, West Africa and the Gulf of Mexico and also opening up new market in the North Sea. Large spreads, long streamers and towing efficiency are the important technical issues to be overlooked in the High Density segment.

DNV is to class the two Ramform series seismic vessels with advanced verification works including hydrodynamics analysis required by extreme principle dimensions and FMEA required by RP notation. The new “Ramform-W” vessels will have class notation +1A1, SPS, ICE-C, E0, HELDK, RP, CLEAN DESIGN,TMON, BIS, NAUT-AW, VIBR, COMF-C(3)V(3).

“DNV has an extensive experience with classifying the hull shapes for previous Ramform series. This is an opportunity for DNV to capitalize our experience with the Ramform series and to help the owner and the builder to further manage the possible risk associated with these unique, tailor-made vessels,” concludes Johan Tutturen.

By Sun Young Park

[mappress]
Source: DNV, September 07, 2011;  Image: PGS