DEVICE TO EXAMINE TECHNICAL CONDITION OF FERROMAGNETIC PIPES Russian patent published in 2011 - IPC E21B47/08 G01N27/87 

FIELD: measurement equipment.

SUBSTANCE: invention relates to devices of nondestructive check methods for pipes, for instance, pipelines of various purpose and casing pipes in oil and gas wells. Device to examine technical condition of ferromagnetic pipes includes contactless transformer sensor with open magnetic conductor, pole tips extended along axis of casing string, magnetising and metering coils. Sensor is installed on rotary non-magnet tubular base, axis of rotation of which is combined with axis of well instrument probe. Magnetic conductor of sensor is arranged in the form of tape spiral stretched along its longitudinal axis and covering non-magnetic tubular base. Number of spiral turns is n=1. Ends of spiral are bent in direction of controlled surface of pipes and are located in plane passing through axis of well instrument. Ends of spiral are cut at the sharp angle, forming pole tips of magnetic conductor with working surfaces, parallel to inner surface of examined pipes. Magnetising coil of sensor is distributed evenly along length of magnetic conductor. Metering coils are arranged in cuts of rectangular shape on pole tips having various length.

EFFECT: increased accuracy of pipes wear and profile detection, provision of possibility to control technical condition of small-diameter pipes.

4 dwg