Download presentation

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.

Similar presentations

OK

Seismic Petrophysics Andy May April 14, 2014. Rock Physics Determine the in-situ acoustic properties of the reservoir and surrounding rocks and their.

Seismic Petrophysics Andy May April 14, 2014. Rock Physics Determine the in-situ acoustic properties of the reservoir and surrounding rocks and their.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on local self government rural Ppt online downloader youtube Ppt on nitrogen cycle and nitrogen fixation definition Ppt on history of atomic model Ppt on bond length chemistry Ppt on principles of peace building commission Ppt on solid dielectrics capacitors Ppt on life cycle of a frog Laser video display ppt online Ppt on personality development slides