The inspection tool is composed basically of a sonde with two coils. The upper (transmitter) coil generates an electromagnetic field in the borehole, casing, and formation. For all practical purposes only the field passing through the casing in front of the coils, and through the medium behind the casing between the coils, creates an electromotive force into the lower (receiver) coil. This electromotive force is out of phase with the transmitted signal. This difference in phase is recorded and is proportional to the average thickness of the casing in front of both coils. Changes in average casing thickness can generally be attributed to corrosion or other damage. Interpretation is greatly enhanced by having a base log, run early in the life of the casing, for comparison with subsequent logs.
terms:electromagnetic_thickness_log
terms/electromagnetic_thickness_log.txt · Last modified: 2023/11/22 08:40 by 127.0.0.1