Many E&P Operators are today assessing the viability of converting existing assets designed for production of hydrocarbons into assets designed for injection and permanent monitoring of CO2. This tendency is mainly driven by laws and regulations aiming at reducing CO2 emissions, and permanent storage in depleted reservoirs is seen as a great enabler to achieve just that. The number of CCS projects is growing because of the prospect to reduce the carbon footprint of oil and gas operations by converting existing production wells to CO2 storage wells. The use of existing wells has certain advantages. On the one hand, there is no need to drill new wells, thereby reducing potential costs, which will be particularly significant when drilling offshore. On the other hand, there is a safety aspect: the fewer wells that penetrate the caprock, the better the integrity of the storage is. The main objective of this work is to create a workflow of converting existing oil/gas production wells into injector/monitoring wells in CCS projects and adapt it to one or several company’s existing wells in the Dutch sector of the North Sea.