Geothermal Reservoir Characterization of Clastic Sedimentary Targets Needs

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Geothermal Reservoir Characterization of Clastic
Sedimentary Targets Needs Gaps
Heinz-Gerd Holl
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standard scenario
seismic section Liebenwalde 01, amplitude
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best case scenario
amplitude stratal slice of Miocene clastic
sediments, offshore Louisiana (Zeng Tucker 2004)
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alternatives?
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geometry of facies distribution
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FMI Lower Elbe Subgroup (4149.75 - 4151.00)
N E S W N
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Lower Elbe Subgroup (4120 - 4202m)
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porosity from logging data
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estimating permeability from logging data
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N(uclear) M(agnetic) R(esonance)
Luthi 2001
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sandstones (Lower Dethlingen Formation)
Depth 4169 m PHI 18.6 K 115 mD
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core porosity permeability
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facies dependent permeability
Castle Byrnes 2005
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conclusions

• seismic scale
• 3-D seismic surveys are essential in areas with
  intensive compartmentalisation
• facies architecture
• Distribution of sedimentary facies has to be
  known for more precise calculation of
  reservoir volumes
• logging resolution
• NMR measurements are best suited for
  petrophysical characterization of reservoirs
• micro scale
• Laboratory measurements of horizontal vertical
  permeabilities are crucial for understanding
  hydraulic response of the reservoir
• Irreducible water saturation of the target has
  to be known to prevent overestimation of
  production values