Inversion of reflection coefficients

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Inversion of reflection coefficients
Supervisors Bjørn Ursin and Henning Omre Part
of URE Uncertainty in Reservoir Evaluation
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Vp and Vs
Dan Russell
Dan Russell
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Wave propagation

• isotropic 3 parameters
• generally anisotropic 22 parameters
• transversely isotropic 5 parameters

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Exact reflection coefficients

• Snells law
• Zoeppritz equations- angles- medium parameters
  in both layers- non-linear and complicated

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Approximated reflection coefficients

• second order
• transversely isotropic
• reduced number of unknowns

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Inversion of P-waves

• forward model rPP cm mTCm
• Jacobian J c (CCT)m
• least square solution
• statistical approach

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Why inversion?

• link between geology and seismic
• P- and S-wave velocities are important rock
  properties
• substitution model in 4D seismic

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Why anisotropic and second order?

• subsurface not isotropic
• valid for larger reflection angles
• valid for larger contrasts

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