Workover and completion fluids are often the same solid-free fluids used in the drilling process and often for the same purpose. The workover of a well, whether it is gas, oil, or an injection well, will alter the physical characteristics of the well, enhancing its production capabilities. This can include scale treatment, cleanout of wax, acid stimulation, fracture stimulation, and water shut-off, gravel packing, recompletion, and reperforations.