We have explored the possibility of obtaining first-order permeability
estimates for saturated alluvial sediments based on the poro-elastic
interpretation of the P-wave velocity dispersion inferred from sonic
logs. Modern sonic logging tools designed for environmental and engineering
applications allow one for P-wave velocity measurements at multiple
emitter frequencies over a bandwidth covering 5 to 10 octaves. Methodological
considerations indicate that, for saturated unconsolidated sediments
in the silt to sand range and typical emitter frequencies ranging
from approximately 1 to 30 kHz, the observable velocity dispersion
should be sufficiently pronounced to allow one for reliable first-order
estimations of the permeability structure. The corresponding predictions
have been tested on and verified for a borehole penetrating a typical
surficial alluvial aquifer. In addition to multifrequency sonic logs,
a comprehensive suite of nuclear and electrical logs, an S-wave log,
a litholog, and a limited number laboratory measurements of the permeability
from retrieved core material were also available. This complementary
information was found to be essential for parameterizing the poro-elastic
inversion procedure and for assessing the uncertainty and internal
consistency of corresponding permeability estimates. Our results
indicate that the thus obtained permeability estimates are largely
consistent with those expected based on the corresponding granulometric
characteristics, as well as with the available evidence form laboratory
measurements. These findings are also consistent with evidence from
ocean acoustics, which indicate that, over a frequency range of several
orders-of-magnitude, the classical theory of poro-elasticity is generally
capable of explaining the observed P-wave velocity dispersion in
medium- to fine-grained seabed sediments