Method and Apparatus for Quantifying Thermal Conductivity and Specific Heat Capacity of Subsurface Geologic Formations

A device, comprising:

• a plurality of temperature sensors and at least one heater element carried by a borehole insertable device housing;
• a power source operable with the at least one heater element;
• and
• an interrogator operable with the plurality of temperature sensors;
• wherein the interrogator is configured to query each temperature sensor of the plurality of temperature sensors after the power source actuates the at least one heater element for a predefined duration to determine a temperature distribution along a length of, and around a circumference of, the borehole insertable device housing.

A system for evaluating ground thermophysical properties, the system comprising:

• an inflatable sleeve carrying a fiber optic sensor defining a fiber Bragg grating extending along a length of the inflatable sleeve parallel to a central axis of the inflatable sleeve;
• at least one heating element situated along the inflatable sleeve such that the at least one heating element is situated between at least some optical fiber sensors of the fiber Bragg grating and at least some other optical fiber sensors of the fiber Bragg grating;
• a power source operable with the at least one heating element;
• and
• an interrogator operable with the fiber Bragg grating;
• wherein the interrogator is configured to query the fiber Bragg grating after the power source actuates the at least one heating element to determine a temperature distribution along the length of, and around a circumference of, the inflatable sleeve.