Methodology for automated verification and qualification of sidewall core recovery depth using borehole image logs

A method of determining depth of a sidewall core sample taken from a borehole relative to a reference log of the borehole, the method comprising:

• obtaining, using a borehole image logging tool, the reference log recorded on a reference log depth scale of a portion of the borehole from which the sidewall core sample has been taken;
• obtaining, using the borehole image logging tool, a borehole image log recorded on a borehole image log depth scale of the portion of the borehole from which the sidewall core sample has been taken;
• generating, by a computer processor, a calibrated borehole image log from the borehole image log and the reference log;
• identifying, using a circle Hough transform, by the computer processor, a candidate sidewall core image artifact in the calibrated borehole image log;
• assigning, by the computer processor, a confidence value for the candidate sidewall core image artifact based on a characteristic of the candidate sidewall core image artifact;
• and
• determining, by the computer processor, using the confidence value, a probability that the sidewall core sample was collected at a certain depth on the reference log depth scale.