PGS completes marathon HD4D survey offshore pre-salt Brazil
OSLO -- On July 17th Petrobras and PGS celebrated completion of the largest HD4D project ever acquired.
During a series of surveys PGS flagship Ramform Sovereign produced 21.3 billion seismic traces while sailing a distance equivalent to 3 ½ times around the Earth’s equator, covering some of the biggest and most significant offshore oil discoveries of the last 30 years.
The mammoth 13031 sq km HD4D program delivers baseline data for future monitoring for some of the most important Brazilian sub-salt oilfields. It began in October 2008 and concluded in July 2012.
Accurate positioning and recording of streamer and source positions ensures that the baseline surveys can be matched with future time-lapse surveys to optimize oil production in decades to come.
The statistics racked up by the Sovereign and her crew during this acquisition campaign are impressive.
Over a period of 45 months, a vast array of recording equipment was towed behind the ship: Fourteen cables, each 8100 m long and packed with electronics were towed in formation, 50 meters apart, i.e. in total 113400 meters of streamer cables (or the distance from Rio de Janeiro to Maceio, along the coast).
The entire streamer array was kept continuously in the water for 9 ½ months implying that all cleaning and maintenance was done from work boats during this period.
Not surprisingly this project has produced a batch of new industry records, largest HD4D spread, largest HD4D survey area, longest continuous deployment. Clearly it has demonstrated the resilience of PGS technology and the skill and determination of the acquisition teams.
Project Success
At a celebratory dinner in Rio de Janeiro, Per Arild Reksnes (PGS Executive Vice President, Marine Contract) thanked both Petrobras and PGS staff for their support and advices contributing to the project’s success:
“Rough seas, adverse currents and a rich flora of sea creatures added challenges that were mastered and managed for 45 months by a competent and committed crew, an excellent vessel and solid onshore support from Petrobras and PGS.”
Likewise, Petrobras expressed their satisfaction with the work done by PGS:
“We would like to sincerely thank the Ramform Sovereign crew for its efforts in making this such a successful long term project and look forward to seeing them back in Brazil in the future.” said Neri Boz (Petrobras, Acquisition Manager)
This project, which has spanned 45 months, has set a series of new industry records.
World Records
Largest active HD4D streamer spread (14 x 8100 m x 50 m separation)
113.4 km
Largest HD4D program 13 031 sq km
Longest continuous deployment of an HD4D spread
9.5 months
Other Statistics
Total distance sailed
136,824 km
Total acquired CMP lines
1,657,131 km
Total acquired prime + infill 20,584 sq km
Total shots recorded
2,352,592
Approximate data volume
481,580 GB
Total data traces acquired
21,342,716,610
08/10/2012