1. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Seismic Navigation GIS
Student presentation GEG2230
Didrik Lilja, May 13, 2014
Student presentation GEG2230 1 / 35

2. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Outline
Background
Marine Acquisition
Survey Classifications
Seismic navigation
Data production
Monitoring
Planning for non-production time
Minimizing the amount of in-fills
Student presentation GEG2230 2 / 35

3. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Outline
Background
Marine Acquisition
Survey Classifications
Seismic navigation
Data production
Monitoring
Planning for non-production time
Minimizing the amount of in-fills
Student presentation GEG2230 3 / 35

4. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Seismic Data
From listening to echoes
Definition
Relating to or denoting geological surveying methods
involving vibrations produced artificially by explosions:
’seismic data show the deep structure of rift systems’.
– Oxford dictionaries1
Used as a tool for oil and gas exploration, but also for
academic research, and possibly for CO2 storage in the future.
1
http://www.oxforddictionaries.com/definition/english/seismic
Student presentation GEG2230 4 / 35

5. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Outline
Background
Marine Acquisition
Survey Classifications
Seismic navigation
Data production
Monitoring
Planning for non-production time
Minimizing the amount of in-fills
Student presentation GEG2230 5 / 35

6. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Towed marine seismic data acquisition2
Figure : Seismic reflections, courtesy of
deliveryimages.acm.org
Figure : Overlap-
ping common
mid-points (CDP),
courtesy of Excess
Geophysics.
2
also referred to as marine seismicStudent presentation GEG2230 6 / 35

7. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Pre-plots and seismic lines
The prospect area sailing routes
Seismic lines
• Lines confined to a
preplot polygon
• Parallel lines
• Line change with
180 deg turns
• Lines organized in
swaths (chunks)
Figure : Preplot polygon, courtsey of survOPT
Student presentation GEG2230 7 / 35

8. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Marine seismic equipment
Sources, cables, navigation equipment++
Student presentation GEG2230 8 / 35

9. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Marine seismic data section
One section per cable
Student presentation GEG2230 9 / 35

10. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Outline
Background
Marine Acquisition
Survey Classifications
Seismic navigation
Data production
Monitoring
Planning for non-production time
Minimizing the amount of in-fills
Student presentation GEG2230 10 / 35

11. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Typical cable configurations
The more cables, the more data sections
2-D surveys
• 1 towed cable
• Sparse line coverage
• Long lines
3-D surveys
• 6-14 towed cables
• Dense line coverage
• Short lines
• Frequent line changes
4-D surveys
• Time-lapse monitoring
• Replicating 3-D survey
• Tight specs
Multi-vessel surveys
Student presentation GEG2230 11 / 35

12. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Typical 3-D layout: 12x8000 m cables, 100 m sep.
Figure : Seismic layout footprint on Oslo, using Google earth and .kmz file from
SurvOPT.
Student presentation GEG2230 12 / 35

13. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Marine seismic survey classifications
Modern acquisition lines
Seismic imaging improves with more illumination angles, as
provided by modern acquisition techniques. These techniques
have complex navigation:
• Crossing lines
• Overlapping lines
• Coil lines
• Extended source–receiver distances
• Often multi-vessel operations
Student presentation GEG2230 13 / 35

14. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Marine seismic survey classifications
Modern illumination techniques
Figure : Various illumination angles, Courtesy of ENI
Student presentation GEG2230 14 / 35

15. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Marine seismic survey classifications
Coil line shooting
Figure : Coil line acquisition has no line changes, courtesy of WesternGeco.
Student presentation GEG2230 15 / 35

16. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Outline
Background
Marine Acquisition
Survey Classifications
Seismic navigation
Data production
Monitoring
Planning for non-production time
Minimizing the amount of in-fills
Student presentation GEG2230 16 / 35

17. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Outline
Background
Marine Acquisition
Survey Classifications
Seismic navigation
Data production
Monitoring
Planning for non-production time
Minimizing the amount of in-fills
Student presentation GEG2230 17 / 35

18. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Data recording is tied to navigation
Seismic data production
Currents can cause drifting on cables (feathering) and/or
impacts the vessel speed over ground.
• Data quality depends on positioning and coverage:
SNR(n) ∼ SNR(1) ·
√
n
n is the no of recordings
SNR is the signal-to-noise for a CMP gather
Student presentation GEG2230 18 / 35

19. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Data recording is tied to navigation
Seismic data production
Currents can cause drifting on cables (feathering) and/or
impacts the vessel speed over ground.
• Data quality depends on positioning and coverage:
SNR(n) ∼ SNR(1) ·
√
n
n is the no of recordings
SNR is the signal-to-noise for a CMP gather
• Data and positioning depends on navigation.
• Data is merged and stored with navigation positioning
data.
Student presentation GEG2230 18 / 35

20. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Seismic Navigation System
A real-time GIS
Production coordinates
• DGPS at vessel antenna
and cable tail buoys.
• Acoustic communication
in a network of modules
attached to the cables.
Figure : Courtesy of National
Oceanography Center,[3].
Student presentation GEG2230 19 / 35

21. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
In-fills
Patching of CMP coverage holes
Loss of CMP coverage
Cables may drift outside of their preplot-assigned bins, besides
the possility of unacceptably noisy data, which calls for in-fill
line patching.
Student presentation GEG2230 20 / 35

22. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Navigation constraints and challenges
A long list...
• Sea environmental (tides, cross-currents, head/tail current)
• Areas restrictions (shoals, protected areas, obstructions, marine mammals)
• Acquisition type (conventional, wide azimuth, rich azimuth, multi-azimuth,
coil)
• Vessel-operational (multi-vessel coordination, planned downtime,
time-sharing)
• Turn rate (tension, depth control)
The remedy
Good navigation planning and monitoring
Student presentation GEG2230 21 / 35

23. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Downtime, line changes and in-fills are costly
Navigation GIS is key to productivity
Student presentation GEG2230 22 / 35

24. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Outline
Background
Marine Acquisition
Survey Classifications
Seismic navigation
Data production
Monitoring
Planning for non-production time
Minimizing the amount of in-fills
Student presentation GEG2230 23 / 35

25. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Real-time monitoring
Information for steering
Figure : SeaPro Nav GIS navigation system, courtesy of Sercel.
Student presentation GEG2230 24 / 35

26. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Real-time monitoring
On-line steering
Vessel and equipment steering
Real-time monitoring ensures
• Data quality: Better coverage and positioning
• Safety: Avoid collisions and cable tangles
• Productivity: Optimal sailing courses, also in conjunction
with downtime
Downtime
The vessel needs to sail at a minimum speed to keep the
equipment afloat. Bad weather, causing too high noise levels
on the data recordings, will force the vessel to circling around
when ”riding the storm off”. The same thing happens in cases
of unexpected downtime events.
Student presentation GEG2230 25 / 35

27. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Equipment steering
Lateral and depth controllers
Figure : eBird - Seismic cable control, courtesy of Kongsberg
Student presentation GEG2230 26 / 35

28. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Outline
Background
Marine Acquisition
Survey Classifications
Seismic navigation
Data production
Monitoring
Planning for non-production time
Minimizing the amount of in-fills
Student presentation GEG2230 27 / 35

29. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Minimizing time spend for line change
Pre-survey planning
Deciding on the preplot
• Fixed polygon boundaries
• Lines in swaths
• Line direction matters
• Aim for fewer and longer
lines → Fewer line
changes
• No of lines vs. vessel
configuration
Student presentation GEG2230 28 / 35

30. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Plan for maintenance downtime
Maintenance during e.g. swath changes
Student presentation GEG2230 29 / 35

31. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Plan for avoiding obstructions
Student presentation GEG2230 30 / 35

32. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Outline
Background
Marine Acquisition
Survey Classifications
Seismic navigation
Data production
Monitoring
Planning for non-production time
Minimizing the amount of in-fills
Student presentation GEG2230 31 / 35

33. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Optimized in-fill line sequence
On-site decisions and back-office support planning
Student presentation GEG2230 32 / 35

34. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Fresnel zone
Fresnel zone reflection
• Vertical resolution
governed by dominant
wavelength λ: λ
4 is the
highest possible
resolution
• The vertical resolution
affects the horizontal
resolution to cause a
Fresnel zone reflection
• Fresnel zone width:
w = 2dλ +
λ2
4 Figure : Courtesy of University of
Wisconsin-Madison
Student presentation GEG2230 33 / 35

35. Seismic
Navigation
GIS
Background
Marine
Acquisition
Survey
Classifications
Seismic
navigation
Data production
Monitoring
Planning for
non-production
time
Minimizing the
amount of in-fills
Saving in-fills with Fresnel zone binning
Fresnel zone binning
Improves the monitoring
of CDP coverage, as used
in (ray trace) processing
• Navigation-integrated
• Saves in-fills
• Provides better
positioning
Figure : Facsimile from a FZB service brochure,
courtesy of Fugro-Geoteam.
Student presentation GEG2230 34 / 35

36. Seismic
Navigation
GIS
Appendix
For Further
Reading
Some references
SurvOPTTM
Marine seismic project optimization
http://www.survopt.com/Marine-seismic-software-features.html
Lecture notes
Department of Geoscience, University of
Wisconsin-Madison
http://www.geology.wisc.edu/courses/g594/Lectures/L15_
SeismicReflectionII.pdf
How seismic surveys work
Courtesy of National Oceanography Center
http://noc.ac.uk/research-at-sea/nmfss/nmep/seismic-exploration
Student presentation GEG2230 35 / 35