Focused fluid flow systems in continental margins

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Focused fluid flow systems in continental margins
Implications and recent advances

• Christian Berndt
• oceansurv, Cowes, Isle of Wight

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Overview

• Introduction
• Focused fluid flow systems
• Relevance of focused fluid flow systems
• Seismic imaging
• Gas hydrates
• Volcanic intrusions
• Geohazards
• High-resolution 3D seismic acquistion system
• Conclusions, outlook and possibilities for
  collaboration

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Fluid flow in passive margins
Berndt, 2005
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Why fluid flow research?

• Fluid flow is the most important link from the
  subsurface to the seabed and many seabed
  processes cannot be understood without this link
• Fluid flow/seepage and sedimentation are the two
  most important carbon fluxes from/to the
  geosphere
• Fluid flow has important implications for
  hydrocarbon exploration and production, but it is
  only understood for very simple cases
• Fluid flow is highly relevant to society on a
  short term as opposed to many other geological
  processes

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Specific fields of research
Fluid flow in passive margins is an important
aspect of the Earth System

• Fluid flow controls the release of carbon into
  the ocean and into the atmosphere
• Fluid flow provides nutrients for chemosynthetic
  ecosystems
• Fluids and gas migration poses the most dangerous
  hazard to offshore exploration and scientific
  ocean drilling
• Fluid flow controls the distribution of natural
  energy resources (oil, gas, condensates, gas
  hydrates)

Weaver et al., 2004
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What does seafloor methane hydrate look like?

• Methane hydrate (clathrate)
• Methane (CH4) gas molecule trapped in lattice of
  water (H20) molecules
• Dissociates (solid ? gas)
• High P, low T

Pictures IfM-Geomar
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Where do we find methane hydrates?
Berndt et al. 2003
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Geophysical response to gas hydrates

• Gas hydrate quantification through
• Seismic velocity response
• Seismic attenuation
• EM

High Q low Q-1
Western Svalbard Hydratech OBS tomography
results, Rossi et al. (2007)
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Evidence for gas hydrates
Vanneste et al., 2006
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Intrusive volcanism in sedimentary basins

• Break-up related volcanism
• Sill intrusions into the sedimentary basins
• Contact metamorphism releasing huge amount of
  carbon into the atmosphere
• Early Eocene climate optimum

Explosive eruption of greenhouse gas
Formation of pipes and explosion craters
Svensen et al. 2005
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Distribution of vent complexes on the Norwegian
Margin

• 735 mapped
• 2-3000 likely present
• 1-2 km below the sea floor

Mud volcanism in Azerbaijan as a modern analogue
to gas explosions? (Photo BBC, 2001)
Svensen et al., 2004
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Volcanic intrusions in the Faeroe Shetland Basin
Vents in the Faeroe Shetland Trough
Berndt and Hili, 2006
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Free gas and slope stability linkage
Masson and Berndt , 2006
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Blow outs from free gas accumulations A major
geohazard

• Gas blow-outs are the single biggest geohazard
  for the offshore industry
• Every year blow-outs happen causing casualties
• 3D imaging of shallow gas accumulations is
  necessary for avoiding blow-outs

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P-Cable projects

• P-Cable is patented technology by VBPR
• Joint development project involving VBPR, NOCS,
  UTromsoe, and IfM-Geomar

• A seismic cable towed perpendicular to the
  vessels steaming direction
• Many single-channel seismic streamers attached to
  a wire held in place by two doors

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Mercator Mud Volcano Gulf of Cadiz
BSR
Berndt et al., 2007
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3D visualisation
Berndt et al., 2007
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Overview

• Introduction
• Focused fluid flow systems
• Relevance of focused fluid flow systems
• Seismic imaging
• Gas hydrates
• Volcanic intrusions
• Geohazards
• High-resolution 3D seismic acquistion system
• Conclusions, outlook and possibilities for
  collaboration

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Summary

• Focused fluid flow systems are extremely relevant
  to society as they control our environment in the
  short term
• Understanding the involved physical processes is
  instrumental for assessing their role in
• climate change
• chemosynthetic ecosystems
• distribution of energy sources
• geohazards (tsunamis, slides, etc.)

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Possible Collaborations

• Influence of halokinesis on fluid migration
  patterns / cementation and drilling problems
  around salt diapirs
• Effects of fluid migration/gas hydrates on sea
  bed stability
• Mud volcanoes as a window to deeper hydrocarbon
  systems
• Thermal structure from BSR depth
• Effect of sill intrusions on sedimentary basins
• Carbon sequestration
• Site surveys

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Contact details
Dr. Christian Berndt oceansurv 32 Denmark
Road Cowes Isle of Wight PO31 7SZ United
Kingdom cbe_at_noc.soton.ac.uk
Consulting projects will be carried out by
oceansurv. Scientific projects will be carried
out either through National Oceanography Centre,
Southampton, or IfM-Geomar, Kiel depending on
project.