Patent ID: 8272438

Claim:
A method for determining pore pressure of a subsurface formation surrounding a wellbore penetrating the subsurface formation, comprising: disposing a temperature sensor and a pressure sensor in a channel, wherein the channel extends from a casing of the wellbore into the subsurface formation; using an impermeable seal to separate the measuring location from the wellbore, the impermeable seal configured to prevent fluids flowing into the channel from the borehole; disposing a pressure sensor and a temperature sensor in the subsurface formation at a measuring location in the channel, wherein the measuring location in the channel is behind the casing of the wellbore; using the pressure sensor and the temperature sensor to measure a pressure and a temperature of the subsurface formation at the measuring location in the channel, wherein the pressure and the temperature of the subsurface formation are measured at the measuring location in the channel over a pre-determined period of time or after the pre-determined period of time, and wherein the pre-determined period of time is longer than a decay time of pressure perturbations caused by the drilling of the wellbore or production of hydrocarbons from the wellbore; storing the pressure and temperature measurements; communicating the stored pressure and temperature measurements to a processor; and processing a pore pressure of the subsurface formation from the pressure and temperature measurements.