Experimental Investigation on Electric Arc Cutting Process for Casing

Many cutting operations are necessary for tubular structures and the wellhead during platform decommission. Electric arc cutting technology for casing and wellhead inner cutting is presented in this study. The electric arc cutting system eliminates the plasma gas system and focuses only on high cutting efficiency given that this cutting operation has no requirements on dimensional accuracy. An arc ignition circuit that is different from traditional arc cutting power is introduced. This study aims to explore cutting performance, such as cutting efficiency and electrode wear. Several cutting parameters, including the working medium, electrode material, electrode diameter, cutting current, and workpiece thickness, are investigated by a series of experiments to analyze cutting performance. Cutting time and electrode wear rate are obtained to evaluate the cutting performance. The morphological features of the experimental results are also investigated. Results show that electric arc cutting technology can be employed to cut a workpiece effectively in sea water with a 4mm tungsten electrode. Cutting performance is affected significantly by cutting current and velocity. A 13 3/8inch casing is cut within 5min in the laboratory with optimal machining parameters, which allow for a good cutting effect.