To understand the significance of the results to follow, we briefly
review a well-known result due to Gassmann (1951) [also see Berryman
(1999b) for a tutorial].
Gassmann's equation relates the bulk modulus *K ^{*}* of a saturated,
undrained isotropic porous medium to the bulk modulus

(6) |

(7) |

We want to emphasize once more that (7) is a result of the theory, not an assumption. It follows immediately from (6) for any isotropic poroelastic medium. Furthermore, the two equations (6) and (7) taken together show that, for isotropic microhomogeneous media, the fluid effect is all contained in the parameter ,where and are the well-known Lamé parameters. This result is crucial for understanding the significance of our later results to oil and gas exploration.

10/16/2003