The invention discloses an
optical fiber drilling
strain gauge, which comprises a strain cylinder, liquid, an end cover, a corrugated
pipe, a bolt, measurement gratings, a protective cover, an optical cable and ground
demodulation equipment, wherein the strain cylinder is used for sensing strain; the liquid is filled in the strain cylinder and used for transferring the strain sensed by the strain cylinder; the end cover is used for sealing; the corrugated
pipe is arranged at the bottom of the strain cylinder and used for sensing the change of pressure in the strain cylinder; the bolt is arranged at the bottom of the strain cylinder and used for filling liquid and sealing; the measurement gratings are fixed at the end of the corrugated
pipe and the bottom of the strain cylinder and used for measuring the end displacement of the corrugated pipe; the protective cover is arranged at the bottom of the strain cylinder and used for protecting the internal structure of the
optical fiber drilling
strain gauge; the optical cable is connected with the
optical fiber drilling
strain gauge arranged at the bottom of a well and the ground
demodulation equipment; and the ground
demodulation equipment is used for demodulating the
wavelength change of the measurement gratings so as to obtain a ground strain value. By using the optical
fiber drilling strain gauge, the problems of
electromagnetic interference,
lightning stroke resistance and null shift of the conventional drilling strain gauge are solved.