Annual Report 2011 - PGS

Operations
Ramform’s Sustainable Productivity Benefits:
Setting New World
Records
The Ramform design is a distinctive PGS
hallmark. The concept of the delta-shaped hull
with a characteristic extremely wide aft beam —
twice the width found on a conventional vessel
— was introduced with the Ramform Explorer in
1995. The benefits of the Ramform vessel were
immediately obvious and PGS continued to
order more of the purpose-built seismic vessels.
Ramform Challenger, the next in the series,
entered the market in 1996, followed by Ramform
Viking and Ramform Valiant two years later and
Ramform Vanguard and Ramform Victory (now
Shigen) in 1999.
Early on, PGS differentiated itself as the most
efficient industry participant. PGS has continued
to focus on high-capacity vessels. The Ramform
Sovereign and Ramform Sterling, which entered
service in 2008 and 2009 respectively, were
even larger and featured more capabilities than
their Ramform predecessors and have executed
notable projects.
Ramform Sovereign was assigned to a major
contract for Petrobras in the second half of 2008
that was scheduled to last approximately one
year. The vessel performed well and several
project extensions ensued. At the time of
writing this report the Ramform Sovereign was
still under contract with Petrobras doing HD4D
mapping of the world’s largest oil fields. In
most of its work, Ramform Sovereign has been
operating with 14 streamers, each 8,100 meters
long, with 50-meter streamer separation. This
dense spread is a deployment of more than 112
kilometers of streamers. By year-end 2011, the
spread had been in the water for 1,000 days
and another 300–400 days of data gathering are
anticipated before survey work is completed. The
size and complexity of the streamer spread is a
world record and Ramform Sovereign has been
performing that record tow on a daily basis for
several years.
Her sister ship, the Ramform Sterling, is
acquiring seismic data using a similarly
impressive spread. In the second half of 2011, she
began a project towing 12 streamers, each 8,100
meters long, with 120-meter separation. In terms
of survey footprint, this is the world’s largest
spread. Ramform Sterling has been logging a
daily maximum production that exceeds 140
square kilometers. This coverage represents
approximately half the size of a small seismic
survey. In its first two weeks of operations
deploying its record spread, Ramform Sterling
acquired more than 1,750 square kilometers of
high-quality seismic data.
Ramform Vanguard, one of the V-class Ramforms,
towed 17 streamers each 3,600 meters long, with
50-meter separation, for a project that began
in the summer of 2011. The assignment was a
4D survey in the North Sea where Ramform
Sovereign had made the first baseline survey in
2008. This performance proves that PGS’ V-class
vessels are capable of towing more than 16
streamers, which had been the previous record
for that type of vessels.
The Ramform Sovereign is here doing a
17 streamer survey in the North Sea in
2008, which was repeated by the Ramform
Vanguard in the summer of 2011.
PGS Annual Report 2011 31