Three oil producing fields in the Danish sector of the North Sea, Gorm, Dan and Halfdan, have been assessed for downhole scale control. All three fields have water injection. To date downhole scaling has not been perceived as a significant production problem in these fields. This paper presents the results of a review of the well service history for each well in the three fields which identified when and where scales had been encountered and estimated the impact of scale on well intervention operations. A thermodynamic equilibrium model for mineral solubilities was used to assess the scaling tendencies of sulphate and carbonate scales from bottom hole to wellhead. The observational data for downhole scale has been compared with the scaling predictions and a risk assessment for carbonate and sulphate scales developed for each well. The implications of this study on industry trends are discussed.