The various forecasts dealing with the probable energy demand in the new century agree upon the fact that renewable energy sources will overshadow the hydrocarbons. This hypothesis, however, is slightly misleading if the absolute amount of oil and gas to be produced is concerned. According to a widely accepted scenario the oil production will increase during the next two decades, and then it will level annually at 2.5 Gt for at least half a century. Thus, altogether 250-260 Gt crude oil must be produced in the next hundred years. The stunning consequence of this demand is that only 380 Gt crude oil exists globally in proven and probable reservoirs. Namely, the production may meet the expectation by the application of such methods which are characterized by 65-70% recovery efficiency. "Sharp shooting the remaining potential" is not a slogan any more, but an imperative necessity! Theoretically, the low recovery efficiency can be attributed to the fact that the formation energy falls short to cover fully the activation energy of the displacement process. Therefore, it is evident that the chemical methods will become the real 'work horses' of hydrocarbon recovery in the coming decades not only in Europe, but also all over the world. So, we have to be prepared for a new era which will be marked, among others, by the more extensive and routine application of sophisticated chemical IOR/EOR methods, and unfortunately, by higher oil price. The papers presented in this volume and written by devoted scientists and petroleum engineers demonstrate well how difficult it is to comply with the ever increasing requirements and to make a good use of our non-renewable natural resources.