Wavenumber illumination analysis validation: Which elastic anisotropic parameters can we resolve?
KAUST DepartmentEarth Science and Engineering Program
Physical Science and Engineering (PSE) Division
Seismic Wave Analysis Group
Permanent link to this recordhttp://hdl.handle.net/10754/661911
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AbstractVertical fractures are often embedded into a finely layered medium, which leads to an effective medium with orthorhombic anisotropy. Ten independent parameters are necessary to completely characterize such a medium, including density and excluding rotations. Through wavenumber illumination analysis, it has been shown that only six of these parameters can be reliably inverted from P - P scattered energy. Here, we demonstrate that with the addition of converted waves, nine parameters can principally be recovered. We also demonstrate that the one-dimensional null space is along a linear combination of the shear-wave dimensionless parameters, g1 and g2, or a linear combination of the elastic coefficients C12 and C66 parameters. This null space can be captured by the Thomsen g parameter if it is introduced into the parameterization. Finally and most importantly, there is still a lot of skepticism around the applicability of multiparameter model wavenumber illumination analysis, so we validate the radiation patterns using finite-difference modeling code. We find that theoretical scattering patterns are in good agreement with numerically modeled wavefields scattered from thin layers. The latter is a step towards applications of similar analysis, initially in the framework of time-lapse monitoring of the reservoirs, where the perturbations of parameters are generally small.
CitationKazei, V., Kabanov, D., & Alkhalifah, T. (2019). Wavenumber illumination analysis validation: Which elastic anisotropic parameters can we resolve? SEG Technical Program Expanded Abstracts 2019. doi:10.1190/segam2019-3216694.1
PublisherSociety of Exploration Geophysicists
Conference/Event nameSociety of Exploration Geophysicists International Exposition and Annual Meeting 2019, SEG 2019