Patent ID: 7782709

Claim:
A method to compute a pore pressure of a subsurface region, comprising: measuring electromagnetic (EM) field data related to EM resistivity at the subsurface region by actuating at least one EM transmitter disposed on at least one of the Earth's surface and on a tool in the subsurface region, and detecting response of the subsurface region using at least one EM receiver disposed in the subsurface region if the EM transmitter is disposed at the Earth's surface or disposed at the Earth's surface if the EM transmitter is disposed on the tool in the subsurface region; measuring acoustic wave data related to acoustic velocity at the subsurface region by actuating at least one acoustic transmitter disposed at least one of the Earth's surface and in the subsurface region and detecting acoustic energy with at least one acoustic receiver disposed at least one of a tool in the subsurface region if the acoustic transmitter is disposed at the Earth's surface or at the Earth's surface if the acoustic transmitter is disposed in the subsurface region; providing a rock physics model characteristic of the subsurface region, wherein the rock physics model comprises a correlation between EM resistivity field data, acoustic wave velocity data, and a pore pressure estimate for the subsurface region, to provide an EM resistivity distribution and an acoustic velocity distribution at the subsurface region; and computing the pore pressure of the subsurface region by adjusting the EM resistivity distribution and the acoustic velocity distribution to the measured EM field data and the measured acoustic wave data.