Scale is the precipitate that forms on surfaces in contact with water as a result of the precipitation of normally soluble solids that become insoluble as temperature increases. The chemical treatment of water associated with oil and gas includes the application of scale inhibitors, such as phosphonates, to help maintain the integrity of equipment that is used during the drilling and production phases. Treatment is used to reduce the concentration of scale forming compounds that can accumulate in production wells, water and disposal wells, flowlines and surface equipment.
The accumulation of scale can reduce flowrates or for instance, lower efficiencies in heat exchangers. Scale inhibiting chemicals can be applied up or downhole of the wellhead.