Method and system to characterize eccentricity modes induced in a manufacturing process of a seamless pipe

Abstract

A method of characterizing at least one rotational and at least one linear eccentricity modes of a wall thickness of a seamless pipe induced during a manufacturing process of the seamless pipe. The method comprises the steps of measuring a wall thickness profile along and around a length of the seamless pipe using a ultrasound-based measurement tool; applying a Fourier transform to the wall thickness profile to obtain a frequency spectrum; identifying one or more amplitude peaks in the frequency spectrum; associating each amplitude peak to a corresponding one of the at least one rotational eccentricity modes; filtering the one or more amplitude peaks out of the frequency spectrum; applying an inverse Fourier transform to the frequency spectrum to obtain a filtered wall thickness profile; and modeling the filtered wall thickness profile into a radial profile of the seamless pipe representative of the at least one linear eccentricity modes.

1 . A method of characterizing at least one rotational and at least one linear eccentricity modes of a wall thickness of a seamless pipe induced during a manufacturing process of the seamless pipe, the method comprises the steps of:
 a) measuring a wall thickness profile along a length and around a radius of the seamless pipe using an ultrasound-based measurement tool;   b) applying a Fourier transform to the wall thickness profile to obtain a frequency spectrum;   c) identifying one or more amplitude peaks in the frequency spectrum;   d) associating each amplitude peak to a corresponding one of the at least one rotational eccentricity modes;   e) filtering the one or more amplitude peaks out of the frequency spectrum;   f) applying an inverse Fourier transform to the frequency spectrum to obtain a filtered wall thickness profile; and   g) modeling the filtered wall thickness profile into a radial profile of the seamless pipe representative of the at least one linear eccentricity modes.   
     
     
         2 . The method of  claim 1 , wherein the ultrasound-based measurement tool comprises a hollow passageway and one or more laser ultrasonic-based measuring probe projecting therein. 
     
     
         3 . The method of  claim 2 , wherein the measuring a wall thickness profile along a length and around a radius of the seamless pipe comprises, concurrently:
 translating the seamless pipe through the hollow passageway;   rotating the one or more measuring probes around the seamless pipe or rotating the seamless pipe; and   probes around the seamless pipe or rotating the seamless pipe.   
     
     
         4 . The method of  claim 1 , wherein the at least one rotational eccentricity modes comprises an eccentricity mode stemming from a rotation of a piercing mandrel during a piercing step of the manufacturing process of the seamless pipe. 
     
     
         5 . The method of  claim 4 , comprising associating the eccentricity mode stemming from a rotation of a piercing mandrel with one or more amplitude peaks of the frequency spectrum at higher frequencies. 
     
     
         6 . The method of  claim 1 , wherein the at least one rotational eccentricity modes comprises an eccentricity mode stemming from a rotation of a rotary hearth heating furnace during a heating step of the manufacturing process of the seamless pipe. 
     
     
         7 . The method of  claim 6 , comprising associating the eccentricity mode stemming from a rotation of a rotary hearth heating furnace with one or more amplitude peaks of the frequency spectrum at lower frequencies. 
     
     
         8 . The method of  claim 1 , further comprising characterizing the rotational eccentricity modes associated with amplitude peaks in the frequency spectrum. 
     
     
         9 . The method of  claim 8 , wherein characterizing the rotational eccentricity modes comprises:
 applying a low-pass filter on the frequency spectrum selected to isolate said amplitude peaks, thereby obtaining a low frequency filtered frequency spectrum;   applying an inverse Fourier transform to the low frequency filtered frequency spectrum, thereby obtaining a low frequency filtered wall thickness profile; and   analyzing sub-profiles of the low frequency filtered wall thickness profile associated with the rotational eccentricity modes.   
     
     
         10 . The method of  claim 1 , wherein filtering the one or more amplitude peaks out of the frequency spectrum comprises applying a high-pass filter to the frequency spectrum. 
     
     
         11 . The method according to  claim 1 , wherein modeling the filtered wall thickness profile includes comprises mapping an internal diameter position of the seamless pipe with respect to the outer diameter position. 
     
     
         12 . The method of  claim 1 , further comprising comparing radial profile of the seamless pipe representative of the at least one linear eccentricity modes to an expected radial profile of the seamless pipe. 
     
     
         13 . A system for characterizing at least one rotational and at least one linear eccentricity modes of a wall thickness of a seamless pipe induced during a manufacturing process of the seamless pipe, the system comprising:
 an ultrasound-based measurement tool to measure a wall thickness profile along and around a length of the seamless pipe; and   a processor and a non-transitory computer-readable medium having stored thereon processor-executable instructions for:
 receiving the wall thickness profile from the ultrasound-based measurement tool; 
 applying a Fourier transform to the wall thickness profile to obtain a frequency spectrum; 
 identifying one or more amplitude peaks in the frequency spectrum; 
 associating each amplitude peak to a corresponding one of the at least one rotational eccentricity modes; 
 filtering the one or more amplitude peaks out of the frequency spectrum; 
 applying an inverse Fourier transform to the frequency spectrum to obtain a filtered wall thickness profile; and 
 modeling the filtered wall thickness profile into a radial profile of the seamless pipe representative of the at least one linear eccentricity modes. 
   
     
     
         14 . The system of  claim 13 , wherein the ultrasound-based measurement tool comprises a hollow passageway and one or more measuring probe projecting therein. 
     
     
         15 . The system of  claim 14 , wherein the one or more measuring probes are laser ultrasonic-based. 
     
     
         16 . The system of  claim 14 , wherein the ultrasound-based measuring tool further comprises a rotational displacement system having the one or more measuring probes mounted thereon such that the one or more measuring probes can perform at least a complete revolution around the hollow passageway. 
     
     
         17 . The system of  claim 13 , wherein the at least one rotational eccentricity modes comprises an eccentricity mode stemming from a rotation of a piercing mandrel during a piercing step of the manufacturing process of the seamless pipe. 
     
     
         18 . The system of  claim 14 , wherein the at least one rotational eccentricity modes comprises an eccentricity mode stemming from a rotation of a rotary hearth heating furnace during a heating step of the manufacturing process of the seamless pipe. 
     
     
         19 . The system of  claim 13 , wherein the non-transitory computer-readable medium further stores thereon processor-executable instructions for characterizing the rotational eccentricity modes associated with amplitude peaks in the frequency spectrum. 
     
     
         20 . The system of  claim 13 , wherein the non-transitory computer-readable medium further stores thereon processor-executable instructions for comparing radial profile of the seamless pipe representative of the at least one linear eccentricity modes to an expected radial profile of the seamless pipe.