DEVICE FOR MAGNETIC FLAW DETECTION OF WELL PIPES Russian patent published in 2020 - IPC G01N27/82 

FIELD: defectoscopy.

SUBSTANCE: use for magnetic flaw detection of well pipes. Essence of the invention consists in that the device for magnetic flaw detection of well pipes includes a downhole module and a ground-based diagnostic system. Downhole module comprises a magnetising device made in the form of a magnetic conductor with a magnetisation coil, a magnetising section of pipes located between the magnetic conductor poles, to a state close to "technical saturation", in the direction along the generatrix of the pipe line, the main scanning magnetometric system, made in the form of a series of magnetically sensitive sensors arranged on flexible "skis" between magnetic conductor poles, on-board controller installed in close proximity to magnetising device and main scanning magnetometric system, each of data inputs of which is connected to output of corresponding magnetosensitive sensor. Output of power supply is connected to inputs of magnetising device, corresponding magnetosensitive sensor and onboard controller, which output is connected to first input of ground controller, connected by second input to selsyn output, and by output to personal computer. Each of magnetically sensitive sensors is connected to on-board controller through sealed connector, is poured with special tight compound, which provides protection against corrosion action, excessive pressure, high temperature of water-oil medium and vibration, is fixed on flexible "ski", which is made with possibility of movement along surface of pipes. Magnetisation coil is placed in protective casing. Magnetic conductor is made in the form of a ring with annular projections located at both ends inside and outside, is equipped with upper or lower dielectric dielectrics and is made with possibility of installation and fixation on the conductor wellhead of the well flange. Magnetisation coil is located between external annular projections, and a number of sensors – between internal ones with pressing inside. Selsyn roller and flexible "skis" of sensors are made with possibility of interaction with external surface of tubing string lifted from the well.

EFFECT: device makes it possible to perform flaw detection outside the pipes at their descent or lifting from the well and to compare defects with each specific pipe (individualize).

1 cl, 4 dwg