Enhanced Arc Control for Magnetically Impelled Butt Welding

摘要

Tubulars are joined for subterranean borehole use in the production of hydrocarbons by a technique of magnetically impelled arc butt (MIAB) welding. Large casing can be accommodated and the weld quality is maintained with control over the pattern of arc movement on the end walls by virtue of relative movements of the tubulars as the arc is generated and the magnetic field is applied. One or both tubulars can be manipulated relatively in a variety of direction to control the movements of the arc as the magnetic field induces circular arc movement along the end walls of the tubulars to heat up the ends to the temperature needed to effectively fuse the wall ends together. Movement can be rotational or axial about a fixed axis or lateral with respect to the axes both with and without skewing of the axes. The movements can be combined to obtain the desired track.

主权项

1. An arc control method for magnetically impelled butt welding, comprising:
bringing ends of tubulars to be welded adjacent each other to create a gap therebetween; producing a condition to create an arc that crosses said gap; applying a magnetic field to said gap; moving said arc around on said ends of said tubulars; moving at least one of said tubulars to control the path of said arc on said ends of said tubulars.