Seismic technology has been an integral part of hydrocarbon exploration since the first seismic exploration patent in 1917 and the first field test in Oklahoma in 1921. Borehole acoustics was first patented in 1935 and successfully developed later as a continuous velocity logging tool, providing a much finer vertical subsurface perspective than seismic acoustics. Rock physics is the crucial discipline that interfaces acoustic wave amplitude and velocities, from seismic or borehole sonic measurements, with petrophysical characterization. The foundation for theoretical rock physics can be traced back to seminal works between the 1940s and the 1960s by Maurice A. Biot and Fritz Gassmann.