Vision 2012/1 - Rolls-Royce

With more and more E&P work taking
place in deep water, operators are
moving to drillships rather than rigs.
Rolls-Royce has established itself as the
principal provider of propulsion units, in
the form of the UUC-series underwater
mountable azimuth thrusters.
Many of the companies now investing in drillships have
this type of thruster on their fleets of semisubmersible rigs,
and the good reputation built up by these sturdy
Rolls-Royce units has ensured that they are ordered for
drillship newbuilds.
In the course of 2011 eleven different companies have
ordered a total of 21 drillships with Rolls-Royce thrusters.
All the vessels are to be built by yards in South Korea, with
deliveries scheduled between 2012 and 2014. The
customers are Seadrill, Noble, Atwood, Ocean Rig, Pacific
Drilling, Vantage, Fred Olsen, Pride (now part of Ensco) and
Aker Drilling (now part of Transocean).
Each vessel will have six thrusters, normally three in a
triangular layout at the bow and three in a similar
arrangement at the stern. Thruster frame size and power
varies from vessel to vessel within the 4,500 – 5,500kW
range per unit, and fixed pitch propellers are specified.
These drillships will work always in DP mode without
anchoring. This places a heavy demand on thruster
performance and reliability. Both efficient propulsion in
transit to a drilling site, and closely controlled positionkeeping
when drilling operations are in progress are
requirements. With operators now very concerned about
emissions and the environment, these propulsion,
manoeuvring and positioning demands have to be met
with the minimum of energy consumption and CO 2
emissions.
Although the UUC-series thrusters are not the lightest
units on the market, they win on performance and
robustness.
“ We have gone for large reduction ratios and big, slow
turning propellers to give maximum thrust, combined
with strong construction for a long service life” says Jarle
Hessen, General Manager, Sales, in Rolls-Royce.
Propulsion for drillships has been a speciality since
propellers and tunnel thrusters were first supplied in 1980,
multiple azimuth thruster installations grew from the mid
1990s and numerous drillships with Rolls-Royce thrusters
have been constructed in the past few years.
Several of the vessels now on order are to the latest
version of the GustoMSC P10 000 design, built under
licence by HHI in Korea. The hull is 210m long and 36m
beam, displacing about 70,000 tonnes.
The drillships are capable of dual activity drilling in water
depths of 3,600m to a total drilling depth of 12,000m.
VISION 1/12
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