1. 3-D Fault Visualization with Fracture Swarms
Multi Azimuth
PSTM
High Resolution Coherence
Petrophysical Analysis,
Shear-log modeling
Multi-Azimuth, Simultaneous
Pre-stack Inversion
Porosity Cross-plotting
Multi Attribute
Visualization
3-D Fault Visualization with Fracture Swarms

2. Simultaneous inversion for Fractures, Shales and Porosity
By Bob Parney Ph.D.,

3. Inversion
We can use Inversion to calculate Elastic Coefficients: Young's Modulus, Poisson's Ratio …
In shales we can locate Brittle/Frac-able rock by cross- plotting Young’s Modulus and Poisson’s Ratio.
We can go a step further and map Elastic coefficients by azimuth.

4. Inversion 1 2 3
Offset
Reflection amplitude is controlled by Vp, Vs,  (density), incident angle
Top of Layer 2: Difference between layer 1 and layer 2
Bottom of Layer 2: Difference between layer 2 and layer 3
Inversion does the “accounting” to find Vp, Vs,  within reservoir

5. Post-stack inversion works by making a connection between impedance contrast, the wavelet, and the final seismic section
P-impedance
Changes in P-imp
Wavelet
Stack

6. Pre-stack inversion: Using gathers or angle stacks we invert
For multiple offsets instead of just the stack
Gather/Angle Stack
P-wave Impedance
S-wave Impedance

7. Examples of Simultaneous Inversion:
Outputs: (1) P-impedance (velocity*density)
(2) S-impedance
(3) Density (less reliable)
Can be used for:
P-impedance/ Sonic Velocity for Lithology
Poissons ratio for Porosity and Vshale
Youngs Modulus: Identify frac zones
Interval Velocity for Pore-pressure
Azimuthal Inversion: Natural fractures and frac zones by azimuth.

8. Example (1): Standard processing vs
Example (1): Standard processing vs. High Frequency (Xfreq) and P-impedance from inversion

9. Example (2): Wire Line P-impedance vs
Example (2): Wire Line P-impedance vs. Poisson’s Ratio, Colored by Effective porosity
Poisson's Ratio
P-impedance

10. Wireline: Rockies Cross plot
Poisson's Ratio
P-impedance
Effective Porosity Log

11. SEISMIC: Crossplot of P-impedance vs
SEISMIC: Crossplot of P-impedance vs. Poissons ratio same zones as effective porosity on wireline
Poisson's Ratio
P-impedance

12. Inline Close up of Porosity

13. Example (3) Shales: Elastic Moduli can be calculated from Inversion results
Poissons ratio  = F (Vp/Vs) = F (Pimp/Simp)
Youngs Modulus E ·  = 2 · (1+ ) · Simp2
(1) Either Cross plot E ·  (density) vs Poisson,
or (2) take  from the inversion and divide to get E

14. High E and low  = Brittle Rock
Cross-plot of Young's Modulus (E) vs. Poisson's Ratio () to Determine “Brittle” Rock for Induced Fracturing in Shale
Poisson's Ratio
Young's Modulus
High E and low  = Brittle Rock

15. Inline of E · and 
Stack
Poisson's Ratio
Young's Modulus ·

16. Cross-plot of Ymodrho to Poir
Stack
Poisson's Ratio
Young's Modulus ·

17. Inversion
We can use Inversion to calculate Elastic Coefficients: Young's Modulus, Poisson's Ratio …
In shales we can locate Brittle/Frac-able rock by cross- plotting Young’s Modulus and Poisson’s Ratio.
We can go a step further and map Elastic coefficients by azimuth.

18. Example (4) Fractured Reservoir Analysis from Seismic
Migrate by sector to reduce uncertainty in source of Anisotropy
Simultaneous Inversion by Sector
Stack then Coherence by Sector
Now have all elastic moduli by azimuth

19. Map view of single set of vertical fractures
P wave (velocity) anisotropy and
S wave (AVO) anisotropy can be
described as ellipse.
P waves and S waves slow
down across fractures
Neither P or S waves “see” fractures
Parallel.

20. Azimuthal changes in velocity and amplitude
Vertical Fractures,
or matrix anisotropy
Dipping reflector
Fault displacement,
Heterogeneity

21. Sort Gathers by Azimuth Prior to Migration
Pre-stack Migration by Azimuth for correct azimuthal amplitudes and velocities
Sort Gathers by Azimuth Prior to Migration N

22. Fracture Workflow Sector by Azimuth PSTM Coherence Pre-stack Inversion
(Angle Stack)

23. Fit Ellipses To Sectored Inversions+ + =
(1) Orientation of Maximum P and S Anisotropy
(2) Magnitude (Max-Min) of Maximum P and S Anisotropy
(3) Magnitude and Orientation of Anisotropy in all other Inversion Products: Poisson's Ratio, Young's Modulus, Lambda Rho, Mu Rho...

24. Magnitude of Poisson's Ratio Anisotropy (Max-Min) over Coherence on all azimuth stack.
Poisson's Ratio and Coherency

25. Magnitude of P-Impedance Anisotropy (Max-Min) over Coherence on all azimuth stack.
P-impedance and Coherency

26. Magnitude of Shear Anisotropy vs. Full Coherence

27. Magnitude of Shear Anisotropy vs. S1 Coherence

28. Magnitude of Shear Anisotropy vs. S2 Coherence

29. Magnitude of Shear Anisotropy vs. S3 Coherence

30. Magnitude of Shear Anisotropy

31. Sector 3 Azimuth High Res. Eigen

32. Summary of Simultaneous Inversion:
Outputs: (1) P-impedance (velocity*density)
(2) S-impedance
(3) Density (less reliable)
Can be used for:
P-impedance/ Sonic Velocity for Lithology
Poisson's ratio for Porosity and Vshale
Young's Modulus: Identify frac zones
Interval Velocity for Pore-pressure
Azimuthal Inversion: Natural fractures and frac zones by azimuth.