METHOD OF DETERMINING THERMAL PROPERTIES OF ROCKS OF SHALE FORMATIONS Russian patent published in 2019 - IPC G01N33/24 G01V9/00 E21B49/00 

FIELD: measurement technology.

SUBSTANCE: invention relates to investigation of rock properties of shale formations. Method comprises determining lithological rock types at intervals of shale thickness depths. Then, samples of rocks of shale sequence for each lithological type are determined by directions of main axes of thermal conductivity of rocks. After that rock thermal conductivity is measured on rock samples for directions corresponding to directions of main axes of rock thermal conductivity at atmospheric pressure and temperature. Volumetric heat capacity of rocks at atmospheric pressure and temperature is measured. Speeds of propagation of longitudinal waves in rocks for directions corresponding to the established directions of the main axes of thermal conductivity of rocks are determined. According to the results of rock thermal conductivity measurements for directions corresponding to the directions of the main thermal conductivity of rocks, volume heat capacity of rocks and propagation speed of longitudinal waves in rocks for directions corresponding to the directions of the main axes of heat conductivity, for each lithological rock type, equations of regression are established between rock heat conductivity and longitudinal wave propagation speeds in rocks for corresponding directions of main axes of rock thermal conductivity, as well as regression equations between volume heat capacity of rocks and propagation speed of longitudinal wave in rocks. Determining heat conductivity of rocks at atmospheric pressure and temperature for directions corresponding to directions of main axes of thermal conductivity of rocks, and volumetric heat capacity of rocks at atmospheric pressure and temperature with availability of data on propagation speed of longitudinal waves in rocks, using for this purpose installed for lithological types regression equations between heat conductivity of rocks and speed of propagation of longitudinal waves in rocks for corresponding directions of main axes of heat conductivity of rocks, as well as the regression equations established for lithological types between the volume specific heat capacity of rocks and the propagation speed of longitudinal waves in rocks. For each lithologic type there determined are dependences of rock thermal conductivity for directions corresponding to directions of main thermal conductivity axes, temperature and pressure, and dependences of volume heat capacity of rocks on temperature and pressure are determined. Method then includes determining thermal conductivity of rocks for directions corresponding to directions of main axes of thermal conductivity of rocks, and volumetric heat capacity of rocks at formation temperature and pressure, using for this purpose rock formations of rocks thermal conductivity for directions corresponding to directions of main axes of heat conductivity of rocks, temperature and pressure and dependence of volume heat capacity of rocks on temperature and pressure.

EFFECT: wider functional capabilities of determining thermal properties of rocks for studying shale sequences, as well as possibility of determining thermal conductivity and volume heat capacity of rocks, taking into account formation temperature and pressure.

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