In the Remote Field Eddy Current Testing (RFECT) of joint casings

the two penetrations of eddy current will enhance the complicacy of analyzing joint casings.Based on our previous studies

the secondary peaks that caused by transmitter passing defects can be removed by employing two pick-up coils in remote field.However

when transmitter at normal pipe locations

there are not any secondary peaks

and nothing will be removed.The pipe information near transmitter is still contained in testing signals.In order to overcome this shortcoming

based on the pick-up coils

this paper deduced the method for removing Normal Pipe Value (NPV) caused by transmitter from testing signals.Firstly

the Wiener deconvolution filter is adopted to identify the signal that can be used to indicate defects.Secondly

based on the signal obtained by Wiener filter

the self-adapting acquisition of NPV is achieved.The correctness and feasibility of proposed method are validated by testing tool and Kesuo #1 well.