Patent ID: 8024124

Claim:
A method for determining maximum horizontal stress in an earth formation, comprising: obtaining fast shear wave velocities (V s1 ) and slow shear wave velocities (V s2 ) for various depths in the earth formation; calculating shear wave anisotropy (A data ) using V s1 and V s2 ; obtaining vertical stress (S v ) and minimum horizontal stress (S h ) for the formation; representing maximum horizontal stress (S H ) using a parameterized function having at least one parameter and using S h and S v as input; determining a value of the at least one parameter by minimizing a cost function that represents a measure of difference between A data and A pred for the various depths and A pred is predicted shear wave anisotropy determined using S v , S h , and S H ; calculating S H using the parameterized function and the value of the at least one parameter; and storing S H in relation to the earth formation.