Dissolution could be a serious problem in the operation of a carbon dioxide flood on a carbonate cemented sandstone. Laboratory core flooding experiments under reservoir conditions demonstrate the effect of the dissolution and the significance of textural properties of the rock. Core flood tests carried out on North Sea core material show similar permeability alteration and effluent concentrations both as a result of channelling and of total dissolution. The presence of residual oil delays the dissolution process. The textural heterogeneity in real rocks make it difficult for existing acidization models to be applied to the interpretation of the laboratory results.