Recent work has shown that localised high-pressure rolling of weld seams can be a very effective means of reducing the damaging residual stresses created during the welding process. In fact, rolling can completely alter the pattern of residual stress in a weld, creating compressive stresses in the regions which are most vulnerable to fracture and fatigue. We aim to study how this effect may be maximised by optimising roller geometry based on finite element analysis results, and how finely the residual stress distribution may be controlled.