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1. (WO2018106389) PULSED EDDY CURRENT CASING INSPECTION TOOL

Pub. No.:    WO/2018/106389    International Application No.:    PCT/US2017/060531
Publication Date: Fri Jun 15 01:59:59 CEST 2018 International Filing Date: Thu Nov 09 00:59:59 CET 2017
IPC: G01N 27/90
E21B 47/00
E21B 47/005
E21B 47/09
G01V 3/18
G01V 3/28
Applicants: PROBE TECNOLOGY SERVICES, INC.
Inventors: ZHANG, Jun
Title: PULSED EDDY CURRENT CASING INSPECTION TOOL
Abstract:
Various downhole logging tools and methods of using and making the same are disclosed. In one aspect, a downhole logging tool (10) for inspecting one or more well tubulars (20, 35, 40) includes a housing (60) adapted to be supported in the one or more well tubulars by a support cable (13). A first transmitter (T120), a second transmitter (T125) and a third transmitter (T130) are positioned in longitudinally spaced-apart relation in the housing and are operable to generate magnetic fields. Driving circuitry is operatively coupled to the first transmitter, the second transmitter and the third transmitter to selectively fire the first transmitter, the second transmitter and the third transmitter in multiple transmission modes to generate magnetic fields to stimulate pulsed eddy currents in the one or more well tubulars. A first receiver (R125) is positioned in the housing to sense decaying magnetic fields created by the pulsed eddy currents. Electronic circuitry is operatively coupled to the first receiver to determine a parameter of interest of the one or more well tubular from the sensed decaying magnetic fields.