Role of Conventional and Unconventional Hydrocarbons in the 21st Century: Comparison of Resources, Reserves, Recovery Factors and Technologies

Abstract The paper deals with the availability of natural hydrocarbons until 2100. Starting point of the evaluation is that the global demand will not be met by production of conventional oil and gas. Basis of the discussion is the comparison of available resources and reserves, recovery factors and technologies. The analysis comprised oil shale, tar sand, gas shale, tight sand gas, coalbed methane and gas hydrates. Taking the data of competent organizations into account, obviously the global resources of unconventional oil and gas significantly exceed the availability of conventional natural hydrocarbons in spite of the fact that their recovery efficiency is extremely low. Although the production cost (operation expenditure) of unconventional hydrocarbons is usually much higher than those of the conventional ones, industrial scale production of tar sand oil, tight sand gas and coalbed methane has started over two decades ago and their contribution to total oil and gas production is already substantial in several countries (US, Canada). The authors stated, however, that wider application of sophisticated technology to recover unconventional hydrocarbons needs more extensive and intensive R&D activity and further, new paradigms are necessary in education, research, production, field management, and governmental regulation. Introduction Energy demand is expected to quadruple in the 21st century (Fig. 1). An energy mix that is undergoing a transition from the current dominance of fossil fuels to a more balanced distribution of energy sources will meet the energy demand. Although the relative importance of hydrocarbons apparently will decrease from 60% (present) to 15% (in 2100), roughly 250–260 billion t of crude oil (annually 2.5 billion t on average through the whole century) must be produced to meet the worldwide demand. That task is enormous if we consider that a little bit than 100 billion t of crude oil has been produced since 1850 and the average production rate was about 0.7 billion t/y. As we will see in the next chapter, only 390 109 t crude oil may exist in proven and probable reservoirs. Namely, the converging opinion of different agencies 1–7 is that the recovery rate of conventional hydrocarbons must be increased from 33–35% at present to 65–70%. Obviously, sophisticated recovery technologies must be routinely used at mostly matured oil fields in the future, however, a serious concern still exists whether that goal might be fulfilled or not. Through the past two decades, the global economic growth and oil demand increased on average by 3.73% and 1.95%, respectively (Fig. 2). Consequently, as a short analyzis made by Yergin 8 a minimum 0.5% increase in oil production is needed to boost the world economy by 1%. Based on that prediction, the industrial oil demand will increase from 20 to 38 MBD (from 1.3 to 2.31 Gt/y) between 1980 and 2030; meanwhile the total oil production probably drops to less than 3 Gt/y by the end of that period 1. Therefore, the skeptic opinions are supported by the facts that just the fuel consumption of transportation or hydrocarbon demand by industry alone will exceed the total crude oil production expected after 2040. It is no doubt, that additional hydrocarbon resources and industrial reserves are keenly necessary to maintain the rate of progress, otherwise the "dwindling supplies of oil and gas, obsolete power net-works and new environmental regulations threaten the western word into a new energy crisis. Consequently, the mankind is becoming again vulnerable to shortage in hydrocarbons, price shock, supply interruptions, and in the worst case, political and military blackmail" (Emerson T.: Newsweek, April 2002).