Abstract: A method can include providing compressional and shear-wave slowness data for a homogeneous, anisotropic formation at deviated borehole angles greater than 40 degrees and less than 90 degrees as defined by a vertical transverse isotropy (VTI) symmetry axis; providing a relationship for normal and tangential compliances (e.g., BN and BT); and, based on the data and the relationship, outputting a model for calculating anisotropy parameter values (e.g., ?0, ?, .?) that characterize the homogeneous, anisotropic formation (e.g., along a borehole angle of 90 degrees). Various other apparatuses, systems, methods, etc., are also disclosed.

Abstract: A method can include providing compressional and shear-wave slowness data for a homogeneous, anisotropic formation at deviated borehole angles greater than 40 degrees and less than 90 degrees as defined by a vertical transverse isotropy (VTI) symmetry axis; providing a relationship for normal and tangential compliances (e.g., BN and BT); and, based on the data and the relationship, outputting a model for calculating anisotropy parameter values (e.g., ?0, ?, ?) that characterize the homogeneous, anisotropic formation (e.g., along a borehole angle of 90 degrees). Various other apparatuses, systems, methods, etc., are also disclosed.

Abstract: The disclosure provides devices, systems and methods for obtaining unaliased wavefield data despite using spatial sampling distances that are higher than conventional techniques and temporal sampling rates that are lower than conventional techniques. The devices can include an array of sensors for sampling a desired wavefield and at least one of its derivatives. The systems can include a multi-level array of such sensor configurations. The methods can include lowering such an array into a borehole and sampling data at distances that are greater than suggested by conventional theory, or lowering a multi-level array into a borehole and simultaneously gathering data at different depth levels.