Where is research on fossil fuels going in times of climate change? A perspective on chemical enhanced oil recovery

Abstract

In a society where the global search for renewable and sustainable sources of energy, chemicals and materials has rapidly become a priority, due to the challenges posed by climate change, one may think that there is no place anymore for research regarding extraction and production of fossil fuels. However, there is no denying that coal, oil and gas still constitute the major source of energy worldwide by far, and humanity will be dependent on them still for decades. As a matter of fact, the global demand of fossil fuels is still increasing rather than decreasing. However, fossil resources are consumed at a much higher rate than they are generated. Only focusing on crude oil, the chances of finding new conventional reservoirs are nowadays low, and this conventional sources are quickly depleting, therefore it is necessary to turn more and more the attention to unconventional sources, such as carbonate reservoirs, tar sands, oil shales and deep off-shore reservoirs. Chemical enhanced oil recovery (cEOR) techniques are already well established in improving macroscopic and microscopic oil displacement, increasing oil production after primary and secondary methods are exhausted. However, these are mostly implemented in reservoirs that normally possess favorable conditions. Research can still contribute in making these processes more efficient and sustainable, especially for unconventional oil, for as long as we will need to extract fossil fuels. After supporting the idea that exploitation of fossil resources cannot stop just yet, this perspective article will highlight recent advances in the field of cEOR, mentioning new developments in traditional methods, such as polymer and surfactant flooding, as well as newer methods, such as nanoparticles, preformed particle gels, and smart waterflooding, plus the various possible new combinations (hybrid EOR). This paper will finally try to shortly outline future directions of cEOR research, with emphasis on sustainable methods, such as CO2 flooding combined with carbon capture and storage strategies, and newly available research tools, such as reservoir-on-a-chip and machine learning.Graphical abstract