142 citations · 260 across the 6 of their papers we have counts for
7 papers
Christoffel equation in the polarization variables
Vladimir Grechka
We formulate the classic Christoffel equation in the polarization variables and solve it for the slowness vectors of plane waves corresponding to a given unit polarization vector.…
Triple singularities of elastic wave propagation in anisotropic media
Vladimir Grechka
A typical singularity of elastic wave propagation, often termed a shear-wave singularity, takes place when the Christoffel equation has a double root or, equivalently, two out of t…
NMO-velocity surfaces and Dix-type formulae in anisotropic heterogeneous media
Vladimir Grechka, Ilya Tsvankin
Reflection moveout of pure modes recorded on conventional-length spreads is described by a normal-moveout (NMO) velocity that depends on the orientation of the common-midpoint (CMP…
Seismic characterization of multiple fracture sets at Rulison Field, Colorado
Ivan Vasconcelos, Vladimir Grechka
Conventional fracture-characterization methods assume the presence of a single set of aligned, vertical cracks in the subsurface. We relax this assumption and demonstrate the feasi…
3D two-point ray tracing for heterogeneous, weakly transversely-isotropic media
Vladimir Grechka, George A. McMechan
A two-point ray-tracing technique for 3D smoothly heterogeneous, weakly transversely-isotropic media is based on Fermat's principle and takes advantage of global Chebyshev approxim…
Inversion of walkaway VSP data in the presence of lateral velocity heterogeneity
Vladimir Grechka, Ilya Tsvankin, Pedro Contreras
Multi-azimuth walkaway vertical seismic profiling (VSP) is an established technique for the estimation of in situ slowness surfaces and inferring anisotropy parameters. Normally, t…