1NTNU, Trondheim

Shibo Xu & Alexey Stovas, NTNU11.06.2015, Loucen, Czech Republic

Estimation of anisotropy parameters by using the CRS approximation

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• 1 The properties like curvature, heterogeneity and anisotropy

are hidden behind the seismic data. To distinguish these properties and see their affect are my main motivations.

• 2 The CRS coefficients depend on the reflector curvatures, heterogeneity and anisotropy, which can be used for estimation.

Motivations

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Method • Based on the reflection and geometry relations, we can get the CRS approximation.

The series coefficients of the CRS approximation depends on curvature, heterogeneity and anisotropy.

• Using the simplest analytical curved reflector (circular reflector) embedded into anisotropic and heterogeneous (layered) medium, we can distinguish these behaviors.

,),( 22

2210

2 hBmAmAAhmTCRS

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Estimation

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RRRRRR

mm

mm

21ˆlimˆ,2)1(ˆlimˆ

),421(ˆlimˆ),1(ˆlimˆ

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0

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The plot of the estimated radius (left) and depth for the center of a circular reflector (right). The EI and VTI cases are shown by blue and red colour.

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Conclusions • 1 Based on the CRS approximation, we propose a new method to evaluate the anisotropy parameters and the model parameters.

•2 The estimated reflector radius and depth are underestimated from the midpoints just above the circle and overestimated when midpoints are far away from the circle.

The estimates in isotropic model parameters: radius (left) and depth for the center of a circular reflector (right). The ISO and VTI cases are shown by blue and red colour.