Patent ID: 7675817

Claim:
A method of evaluating an earth formation having at least two components in a matrix of the formation, the method comprising: (a) measuring a compressional velocity and a shear velocity of the formation through a casing in a borehole in the earth formation; (b) measuring a porosity of the earth formation through the casing; (c) measuring a fraction of one of the at least two components of the earth formation through the casing; and (d) using a two-component mixing model, the measured compressional velocity, the measured shear velocity, the measured porosity and the measured fraction of the one component of the earth formation to estimate a property of a fluid in the formation; wherein each component of the two-component model satisfies a relation of the form: K sat K o - K sat = K K m - K + K f ϕ ⁡ ( K o - K f ) where φ is a porosity, K is a frame modulus, K m is a grain modulus, and K f is a fluid modulus.