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2 Overview
Electro-magnetic Thickness Instrument is used to measure the thickness of downhole metal pipe, which can reflect
the corrosion degree of casing. The sensor array of the instrument is composed of 16 (12) independent sensors.
Every sensor can get a curve of casing thickness.
2 Operating Principle
The tool generates an alternating magnetic wave, which propagates out of the tool and permeates through the casing. Once outside the casing, the wave travels a short distance along the length of the pipe, before re-entering the
well bore in order to complete its path. It is in this region, where the magnetic wave re-enters the well bore,
that the sensor array is positioned. Each sensor then detects localized information about the magnetic wave that
has traveled through the casing wall.
Electro-magnetic Thickness Instrument in Wireline Logging Tools
