Analysis of Abnormally Weak Signals in Passive Casing Collar Locator During Logging
The Casing Collar Locator(CCL)measures the number of couplings in the oil and casing in the well,so as to realize the judgment and verification of the depth of the downhole equipment,as well as the accurate measurement of the depth of the oil and casing.At the same time,it judges the damage position of the oil and casing,and identifies the perforating depth or interval.In the field application process,it has been encountered many times that the coupling signal is weak or the signal-to-noise ratio is poor,which makes it difficult to distinguish the coupling signal from the noise signal,and affects the accuracy and efficiency of the field operation.After the workshop investigation,it is confirmed that the magnetic steel and coil are in good condition.This paper conducts an in-depth analysis of the reasons.