Impact of T. J. Plona's Observation and Quantification of the Biot Fast and Slow Waves

摘要

In two well-know papers published in 1956 M. A. Biot developed a theory of acoustics in porous fluid-filled media which predicted the existence of two longitudinal /compressional waves, Fast and Slow, as well as a transverse/Shear wave. The relevance of this theory to real materials was long discounted by many researchers because no one had observed two distinct compressional waves in any porous medium. This changed with the publication in 1980 of Plona's seminal paper in which he reported Fast and Slow compressional waves, as well as the Shear wave, in a number of man-made samples saturated with water. This result led immediately to an explosion in the understanding of acoustics in porous media, which I will review. Furthermore, this understanding led directly to the development of of a commercial service whereby the fluid flow resistance of an oilfield formation can be determined by means of acoustic measurements taken within the borehole.