Synthetic Study of Azimuthal AVO Analysis with Anisotropic

Spreading Correction

Ellen (Xiaoxia) & Ilya

Acknowlegment

• Andreas Rueger

Model Geometry

Spreading: Moveout Parameters

Moveout-based Anisotropic Spreading Correction (MASC)

input parameterspick the raw amplituderemove the source and receiver directivitycorrect for geometrical spreading calibrate the corrected amplitude

Moveout-based Anisotropic Spreading Correction (MASC)

input parameters, pick the raw amplituderemove the source and receiver directivitycorrect for geometrical spreading calibrate the corrected amplitude

Parameters for Orthorhombic Media

Model 1

x1

x2

x3

Synthetics for Model 1T

ime

(s)

3

2

1

Offset (km) Offset (km) Offset (km)0 1 2 0 1 2 0 1 2

azimuth 0o azimuth 45o azimuth 90o

Reconstructed Reflection Coefficients

Horizontal slowness (s/km)0 0.15 0.3

0.0

0.05

0.1

azimuth 0o

azimuth 90o

azimuth 45o

Comparison of Spreading

Offset (km)0 1 2 3

8

7

6

5

4azimuth 0o

azimuth 90o

azimuth 45o

Sp

read

ing

(km

)

Reconstructed RCs using t2 gain

Horizontal slowness (s/km)0 0.15 0.3

0.0

0.05

0.1

azimuth 0o

azimuth 45o

azimuth 90o

Model 2

x1

x2

x3

Synthetics for Model 2Offset (km) Offset (km) Offset (km)

0 1 2 0 1 2 0 1 2

Tim

e (s

)

3

2

1

azimuth 0o azimuth 45o azimuth 90o

Reconstructed Reflection Coefficients

0.06

-0.02

Horizontal slowness (s/km)0 0.15 0.3

0.00

0.04

0.02azimuth 0o

azimuth 45o

azimuth 90o

Reconstructed RCs using t2 gain

0 0.15 0.3

0.06

0.04

0.02

0.00

-0.02

Horizontal slowness (s/km)

azimuth 0o

azimuth 45o

azimuth 90o

Model 3

x1

x2

x3

Synthetics for Model 3T

ime

(s)

3

2

1

Offset (km) Offset (km) Offset (km)0 1 2 0 1 2 0 1 2

azimuth 90oazimuth 45oazimuth 0o

Reconstructed Reflection Coefficients

Horizontal slowness (s/km)0 0.15 0.3

-0.06

-0.10

-0.14

-0.18

azimuth 0o

azimuth 90o

azimuth 45o

Reconstructed RCs using t2 gain

Horizontal slowness (s/km)0 0.15 0.3

-0.06

-0.10

-0.14

-0.18

azimuth 0o

azimuth 90o

azimuth 45o

Influence of Transmission Loss

Horizontal slowness (s/km)0 0.15 0.3

Model 3

0.0

-0.1

0.1

0.2

azimuth 0o

azimuth 90o

azimuth 45o

Conclusions

• RCs accurately reconstructed

• fits into processing sequence

• critical for quantitative AVO

• important for qualitative AVO

• transmission loss negligible

Acknowledgment

• Andreas Rueger

• Debashish Sarkar

• Dave

• Ken