There is no such thing as empty oil reservoirs. Any reservoir that goes into decline will eventually reach a state where stimulation methods are not cost-effective anymore for the price one gets for the oil. Thats when the wells are discontinued. One such stimulation method is pumping a lot of CO2 into a reservoir. CO2 makes the oil flow better and increases the pressure which helps oil production. And now taxes pay for that.
A Danish project to store captured CO2 in North Sea reservoirs that were once filled with oil and gas moved a step closer to becoming operational, after winning approval from new stakeholders.