This work contributes to a concept proposal for obtaining pore fluid viscosity and formation permeability from thermoacoustic measurements (i.e., conducting acoustic logging of pore fluid mobility at different temperature conditions in the wellbore). The acoustic method for mobility estimation from Stoneley wave attenuation and dispersion is widely used in the industry. Currently, nearly all wireline measurements are performed at static thermodynamic conditions in the wellbore. But what happens if thermodynamic conditions are changed and logs are run at different temperature conditions at a given depth? In this case, the measurements of the pore fluid mobility at different temperatures allow obtaining additional information on the pore fluid viscosity and improve the accuracy of permeability estimation by the acoustic method. This work includes experimental and modeling verification of the suggested thermoacoustic method. The experiments were on laboratory core samples; finite-difference poro-visco-elastic code was used for the modeling. The applicability of the method is shown to be dependent on the temperature difference of the formation, accuracy of the Stoneley wave dispersion and attenuation measurements, and the in-situ wellbore pore fluid viscosity, temperature, and pore pressure.
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