Patent ID: 8175807

Claim:
A method for determining properties of a subterranean formation, comprising: determining at least one characterization parameter based on wave velocity measurement data, wherein the at least one characterization parameter is a variable dependent on a rock type of the subterranean formation; measuring a first elastic coefficient of a plurality of elastic coefficients using a sonic measurement tool; determining a second elastic coefficient of the plurality of elastic coefficients as a function of at least the first elastic coefficient based on a parameterized approximation equation comprising at least one selected from a group consisting of C 13 =(C 33 −χC 44 ), C 11 =χ′*C 33 *C 66 /C 44 +(1−χ′)*C 33 , C 12 =ξC 13 and C 13 =ζC 33 −2C 44 , and C 11 = A ⁢ ⁢ C 33 ⁢ C 66 C 44 + B , wherein the plurality of elastic coefficients comprise C 13 , C 33 , C 44 , and C 66 , and wherein the at least one characterization parameter comprises at least one selected from a group consisting of χ, χ′, ξ, ζ, A, and B; determining an anisotropic stress profile of the subterranean formations based on a stiffness matrix of the subterranean formation comprising the plurality of elastic coefficients; and displaying the anisotropic stress profile of the subterranean formations.