Method and apparatus to assess the thermal damage caused to a PCD cutter using capacitance spectroscopy

A method of determining wear resistance of a downhole tool, comprising:

• measuring capacitance values of a first plurality of leached polycrystalline diamond compact (PDC) cutters;
• destructively testing wear resistance of each cutter of the first plurality to obtain calibration data;
• brazing a second plurality of leached PDC cutters to the downhole tool, the first plurality and the second plurality being of the same type;
• after brazing, measuring a capacitance value of each cutter of the second plurality;
• and
• determining an estimated wear resistance of each cutter of the second plurality using the respective measured capacitance value of each cutter of the second plurality and the calibration data,
• wherein the capacitance value of each cutter of the second plurality is measured by:
• obtaining a capacitance measuring device comprising a positive terminal and a negative terminal;
• electrically coupling a first wire from the positive terminal to a leached layer of the respective cutter;
• and
• electrically coupling a second wire from the negative terminal to a surface of the downhole tool.