Sonic measurements in hydrocarbon wells provide precious information for rock mechanical and geophysical studies. Compressional wave velocity is easily recorded and is available for all wells. However, measurement of shear wave velocity is more complicated
and these measurements are not available in old wells owing to lack
of technologic tools in those days. Run of recent tools in old wells is
not practical for most of them due to prevailing casing completion.
Therefore, a quantitative formulation between conventional well
logs (available in all wells) and shear wave velocity eliminates the
mentioned problems and makes it possible to perform geophysical
and geomechanical studies. Combination of shear and compressional
wave velocities measurements adds up to invaluable source
of information for lithology identification