Detection of pipe characteristics with a remote field eddy current

摘要

Methods for detection of pipe characteristics, such as defect detection of downhole tubulars and overall thickness estimation of downhole tubulars, utilizing remote-field eddy current technique. A defect detection method may further include disposing a defect detection tool in a wellbore, wherein the defect detection tool comprises a transmitter and a plurality of receivers, recording measurements for a plurality of channels, utilizing pre-calculated estimation curves corresponding to the plurality of channels at a plurality of defected candidates to obtain thicknesses corresponding to the plurality of channels at each defected candidate; and evaluating variations for the thicknesses by computing standard deviations between the thicknesses obtained for the plurality of channels at each defected candidates utilizing a minimum variation, and computing an overall thickness change using overall thickness estimations for the plurality of defected candidates.