Method and device for calibrating depth of optical fibre in well

A device for calibrating a depth of an optical fibre in a well, comprising:

• a seismic wave field data acquisition unit, used for acquiring borehole seismic wave field data based on an optical fibre acoustic wave sensor;
• a first arrival time determination unit, used for determining first arrival time information based on the borehole seismic wave field data;
• a downgoing wave first arrival amplitude determination unit, used for determining a downgoing wave first arrival amplitude based on the first arrival time information and the borehole seismic wave field data;
• a feature point determination unit, used for determining an optical fibre amplitude feature point based on the downgoing wave first arrival amplitude;
• an optical fibre parameter determination unit, used for determining a wellhead initial position and a receiving point spacing of the optical fibre in the well based on the optical fibre amplitude feature point and logging curve feature points;
• and
• a depth calibration unit, used for determining depth calibration information of the optical fibre in the well based on the wellhead initial position and the receiving point spacing.