Studies to date have generally shown that individual CO2-EOR offshore projects are uneconomic except under questionable assumptions. The present study is based on an interconnected cluster of nine oilfields in the Central North Sea linked to an onshore CO2 collection hub by a set of existing and new pipelines. Monte Carlo simulation modelling was undertaken of the prospective returns to investments in CO2-EOR in the fields. Relatively high oil prices were employed for the study period (2020-2050) and two contrasting CO2 transfer price scenarios, the first being the Carbon Price Floor (CPF) introduced by the UK Government and the second being relatively low negotiated prices reflecting recent and prospective levels under the EU-ETS. At CPF prices the investment returns were all found to be negative, but at prices averaging 10 per tonne positive returns were generally achieved. The study emphasises the importance of CO2 prices and the taxation system in determining the viability of the investments. (C) 2013 Elsevier Ltd. All rights reserved.