Welding Thermal Accumulation During Butt-welding of Coiled Tubing

Abstract

As a kind of advanced continuous coiled pipe, coiled tubing is widely used in oiled well engineering, it has high strength and good corrosion resistance. But unfortunately, its outstanding properties will be intensively affected by butt welding process. The welding thermal accumulation during butt-welding was studied in this paper. Based on double ellipsoid source model, a finite element model for butt welding process was developed and the temperature distribution was analyzed. The results show that for bead on plate welding, the weld pool size of tubing welding is smaller than that of plate welding because of dispersion of arc. Thermal accumulation can be observed around start point, where two peak temperatures appeared and cooling time is a little longer than plate welding.