Abstract: A method of modelling a hydrocarbon-containing reservoir which is representative of such reservoir in at least one physical characteristic such as reservoir porosity or permeability. Data, such as reservoir porosity is firstly determined. Such data is then transformed into printing instructions for a 3D printer. The 3D printer is used to print a reduced-scale model which is representative of the reservoir in respect of the at least one physical characteristic, such as reservoir porosity. A method of comparative testing of different hydrocarbon recovery techniques on a single hydrocarbon-containing reservoir is also disclosed and claimed.