elements of 3d seismology: introduction to interpretation
DESCRIPTION
Elements of 3D Seismology: Introduction to Interpretation. Christopher L. Liner University of Tulsa November 2003. Synthetic Seismogram. Assume: Zero offset, zero dip, and v(z). Synthetic Seismogram. Travel times Layer thickness and velocity Reflection coefficients Velocity and density. - PowerPoint PPT PresentationTRANSCRIPT
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Elements of 3D Seismology:Introduction to Interpretation
Christopher L. LinerUniversity of Tulsa
November 2003
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Synthetic Seismogram
Assume: Zero offset, zero dip, and v(z)
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Synthetic Seismogram
•Travel times•Layer thickness and velocity
•Reflection coefficients•Velocity and density
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Synthetic Seismogram
•R0 is important•Reflection coefficient•Normal incidence (zero offset)•Values [-1,+1]
•Commonly [-.3,.3]•I = acoustic impedance
•Rock property influences•Mineralogy•Porosity•Pore fluid
•Seismic peak amplitude ~ R0
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Synthetic Seismogram
Wavelet
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Synthetic Seismogram
Wavelet
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Synthetic Seismogram
Is peak amplitude ~ R0 …. ?Modeling can supply the answer.
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(A)Field data stack(B) Stack of Z.O. synthetic(C) Detail of B(D)Gamma log(E) AVO synthetic
(F) Resistivity log(G) Bulk density log(H) P-wave sonic(I) S-wave sonic(J) Vp/Vs ratio
Lindsay and Koughnet, 2001, TLE
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Tuning
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Tuning
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Vertical Resolution
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Vertical Resolution
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Tuning and Resolution
Tuning and resolution thickness are equal– Wavelength/4 = v/(4 f)– v is interval velocity of the thin bed– f is dominant, or average, frequency
• About 20-40 Hz
Subresolution thickness mapping– Difficult because top/base events commingle– Tools
• Tuning curves, spectral decomposition,+
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