Patent ID: 7349807

Claim:
A method for determining a property of a subsurface region of an earth formation, the method comprising: (a) obtaining a velocity of the subsurface region from a seismic survey; (b) estimating from the obtained velocity: (A) a formation pore pressure of the subsurface region using a density estimated using the velocity and an effective stress of the subsurface region estimated using the velocity, and (B) an uncertainty associated with the estimated pore pressure of the subsurface region, said uncertainty depending at least in part on an uncertainty in the obtained velocity; and (c) using the determined formation pore pressure for establishing a minimum and maximum mud weight used in drilling a borehole in the earth formation based on at least one of: (i) the pore pressure of the subsurface region; (ii) a strength of a rock constituting the subsurface region; (iii) a maximum principal stress in the subsurface region; (iv) a minimum principal stress in the subsurface region; and (v) a collapse pressure that prevents drilling.