Economically and Environmentally Sustainable Enhanced Oil Recovery - M. R. Islam

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time approaching infinity are sustainable (Khan and Islam, 2007). The only problem with fossil fuel technology is that they are rendered toxic after they are refined using high heat, toxic chemicals and catalysts.

Graph of energy content versus natural processing time displaying an ascending curve with 4 diamond makers lying on it for wood, coal, oil, and natural gas (from bottom to top).

      Figure 2.15 Energy content of different fuels (MJ/kg) (from Spight and Islam, 2016).

      From the above discussion, it is clear that fossil fuels can contribute to a significant amount of energy by 2050. It is widely considered that fossil fuels will be used up soon. However, there are still huge reserves of fossil fuel. The current estimation on the total reserves is based on the exploration to-date. If one assumes a priori that reserves are declining with time (Figure 2.16a), one fails to see the role of exploration and drilling activities. As the number of drillings or exploration activities increases, more recoverable reserves can be found (Figure 2.16c). In fact, Figure 2.16 is equally valid if the abscissa is replaced by ‘time’ and ordinate is replaced by ‘exploratory drillings’ (Figure 2.16b). For every energy source, more exploration will lead to a larger fuel reserve. This relationship makes the reserve of any fuel type truly infinity, and alone can be used as a basis for developing technologies that exploit local energy sources.

Graph of reserves versus time displaying a descending line (a). Graph of explorations versus time displaying a descending line (b). Graph of reserves versus exploration displaying an ascending line (c).

      Figure 2.16 Fossil fuel reserves and exploration activities.

      The US oil and natural gas reserves reported by the EIA consistently show that the reserves over the years have increased (Table 2.6 gives a sampler). These additional reserves were estimated after the analysis of geological and engineering data. Hence, based on currently observed patterns, as the number of exploration increases, the reserves will also increase.

      Figure 2.17 shows that the discovery of natural gas reserves increases as exploration activities or drillings are increased. Biogas in naturally formed in swamps, paddy fields and other places due to the natural degradation of other organic materials. As shown in previous sections, there are huge gas reservoirs including deep gas, tight gas, Devonian shale gas and gas hydrates, which are not yet exploited. The current exploration level is limited to shallow gas, which is a small fraction of the total natural gas reserve. Hence, by increasing the number of exploration activities, more and more reserves can be found which indicates the availability of unlimited amount of fossil fuels. As the natural processes continue, formation of natural gas also continues for ever. This is applicable to other fossil fuel resources such as coal, light and heavy oil, bitumen and tar sands.

      Table 2.6 US crude oil and natural gas reserve (Million barrels) (From Islam, 2014).

Year Reserve % Increment
Crude Oil Reserve 1998 21,034
1999 217,65 3.5%
2000 22,045 1.3%
2001 22,446 1.8%
Natural Gas 1998 164,041
1999 167,406 2.1%
2000 177,427 6.0%
2001 183,460 3.4%
Graph of discovery of new reserves vs. exploratory drilling activities with an ascending curve having diamond markers lying on it for biogas, shallow gas, deep gas, tight gas, Devonian Shale gas, and gas hydrates.

      Figure 2.17 Discovery of natural gas reserves with exploration activities (From Islam, 2014).

      Figure 2.17 shows the variation of resource base with time starting from biomass to natural gas. Biomass is available on earth in huge quantities. Due to natural activities, the biomass undergoes various changes. With heat and pressure on the interior of the earth, formation of fossil fuels starts due to the degradation of organic matters from the microbial activities. The slope of the graph indicates that the volume of reserve decreases as it is further processed. Hence, there is more coal than oil and more oil than natural gas, meaning unlimited resources. Moreover, the energy content per unit mass of the fuel increases as the natural processing time increases. The biomass resource is renewable and the biological activities continue on the earth, the process of formation of fossil fuels also continues forever. From this discussion, the conventional understanding of there being a fine boundary between renewable and non-renewable energy resources is dismantled, and it is concluded that there is no boundary between the renewable and non-renewable in the long run, as all natural processes are renewable. The only problem with fossil fuels arises from the use of toxic chemicals and catalysts during oil refining and gas processing. Provided the fossil fuels are processed using the natural and non-toxic catalysts and chemicals, or make use of crude oil or gas directly, fossil fuel will still remain as a good supplement in the global energy scenario in the days to come. These resources are totally recyclable.

      Notes

      1 1 Organic mercury compounds, sometimes called organomercurials, are those containing covalent bonds between carbon and mercury. Examples are methylmercury, dimethyl-mercury and methylmercury chloride (methylmercuric chloride).

      2 2 For details of the galaxy model, see Islam (2014).

      3 3 On the yang side of the yin-yang are six organs, namely, gall bladder, stomach, small intestine, large intestine, bladder and triple burner.

      4 4 ‘Intangible’ would

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