Pipeline Tool with Composite Magnetic Field for Inline Inspection

Abstract

Embodiments of an inline inspection (“ILI”) tool ( 10 ) of this disclosure include a plurality of composite field systems ( 20 ) arranged circumferentially about the body of the ILI tool, each composite field system including multiple magnetic circuits ( 60 ) to produce a composite or resultant angled field © relative to the target, along with a sensor array or circuit ( 40 ) configured for magnetic flux leakage (“MFL”) or magnetostrictive electro-magnetic acoustic transducers (“EMAT”) implementations. In embodiments, the pole magnets ( 61 ) of the magnetic circuits are oriented in the axial direction of the tool body rather than in the direction of the resultant angled field. The same is true of the sensors ( 43 ). This composite field system approach provides options to design geometries that were not previously possible in prior art single-circuit helical MFL designs and EMAT designs.

1 . A tool body ( 10 ) adapted for use in inspecting a wall of a tubular, the tool body having an axial direction and a transverse direction and further comprising:
 a first magnetic circuit ( 60 A) and a second magnetic circuit ( 60 B) located an exterior surface of the tool body, each magnetic circuit including a north pole magnet ( 61 N) and a south pole magnet ( 61 S) spaced apart and opposite one another;   the first magnetic circuit having a first magnetic field with a first orientation, the second magnetic circuit having a second magnetic field with a second orientation perpendicular to that of the first orientation;   the first and second magnetic circuits together forming a rectangular shape.   
     
     
         2 . The tool body of  claim 1 , wherein, an orientation of a combined magnetic field of the first and second magnetic circuits is between, and different than, the first and second orientations. 
     
     
         3 . The tool body of  claim 1 , wherein, the first magnetic field has a first strength and the second magnetic field has a second strength different than that of the first strength. 
     
     
         4 . The tool body of  claim 1 , wherein, one of the first and second orientations is in the axial direction and another one of the first and second orientations in the transverse direction. 
     
     
         5 . The tool body of  claim 1 , further comprising:
 a computer processor, the computer processor adapted to perform a vector addition of the first and second magnetic fields.   
     
     
         6 . The tool body of  claim 1  further comprising:
 a magnetic flux sensor located within the rectangular shape. 
 
     
     
         7 . The tool body of  claim 1 , further comprising:
 an electro-magnetic acoustic transducer located within the rectangular shape.   
     
     
         8 . The tool body of  claim 2 , further comprising:
 a sensor array including sensors ( 43 ) located within the rectangular shape, the sensors oriented at an angle relative to the axial direction different than that of the orientation of the combined magnetic field.   
     
     
         9 . The tool body of  claim 8 , wherein, the orientation of the combined magnetic field is at an angle α in a range of 40° to 50°. 
     
     
         10 . The tool body of  claim 1 , wherein, the north and south pole magnets of one of the first and second magnetic circuits are spaced apart from one another a distance at least as great as a length of the north and south pole magnets of another one of the first and second magnetic circuits. 
     
     
         11 . A method for inspecting a wall of tubular, the method comprising:
 collecting data indicative of wall quality using a tool body having an axial direction and a transverse direction and further including:
 a first magnetic circuit ( 60 A) and a second magnetic circuit ( 60 B) located an exterior surface of the tool body,
 each magnetic circuit including a north pole magnet ( 61 N) and a south pole magnet ( 61 S) spaced apart and opposite one another; 
 
 the first magnetic circuit having a first magnetic field with a first orientation, the second magnetic circuit having a second magnetic field with a second orientation perpendicular to that of the first orientation; 
 the first and second magnetic circuits together forming a rectangular shape. 
   
     
     
         12 . The method of  claim 11 , wherein, an orientation of a combined magnetic field of the first and second magnetic circuits is between, and different than, the first and second orientations. 
     
     
         13 . The method of  claim 11 , wherein, the first magnetic field has a first strength and the second magnetic field has a second strength different than that of the first strength. 
     
     
         14 . The method of  claim 11 , wherein, one of the first and second orientations is in the axial direction and another one of the first and second orientations in the transverse direction. 
     
     
         15 . The method of  claim 11 , wherein, the tool body further comprises a computer processor, the computer processor adapted to perform a vector addition of the first and second magnetic fields. 
     
     
         16 . The method of  claim 11 , wherein, the tool body further comprises a magnetic flux sensor located within the rectangular shape. 
     
     
         17 . The method of  claim 11 , wherein, the tool body further comprises an electro-magnetic acoustic transducer located within the rectangular shape. 
     
     
         18 . The method of  claim 12 , wherein, the tool body further comprises a sensor array including sensors ( 43 ) located within the rectangular shape, the sensors oriented at an angle relative to the axial direction different that of the orientation of the combined magnetic field. 
     
     
         19 . The method of  claim 18 , wherein, the orientation of the combined magnetic field is at an angle α in a range of 40° to 50°. 
     
     
         20 . The method of  claim 11 , wherein, the north and south pole magnets of one of the first and second magnetic circuits are spaced apart from one another a distance at least as great as a length of the north and south pole magnets of another one of the first and second magnetic circuits. 
     
     
         21 . A method for providing a tool body with an oblique magnetic field for use in pipeline inspection, the tool body having an axial direction and a transverse direction, the method comprising:
 locating a first magnetic circuit ( 60 A) and a second magnetic circuit ( 60 B) on an exterior surface of the tool body, each magnetic circuit including a north pole magnet ( 61 N) and a south pole magnet ( 61 S) spaced apart and opposite one another, pole magnets of one of the first and second magnetic circuits oriented in the axial direction and pole magnets of another one of the first and second magnetic circuits oriented in the transverse direction;
 the first magnetic circuit having a first magnetic field with a first orientation, the second magnetic circuit having a second magnetic field with a second orientation perpendicular to that of the first orientation; 
 the first and second magnetic circuits together forming a rectangular shape and producing a combined magnetic field having an orientation that is oblique relative to the axial direction; 
   placing one or more sensors ( 43 ) within the rectangular shape, the one or more sensors oriented at an angle relative to the axial direction different than that of the orientation of the combined magnetic field of the first and second magnetic fields; and   including a computer processor having instructions to calculate the combined magnetic field by performing a vector addition of the first and second magnetic fields.