The solution to our expected critical minerals shortages might not be nestled among the stars or hidden in the depths of the ocean, but rather lying beneath our very feet in the often-overlooked byproducts of an entirely different industry: oil and gas.

The extraction of crude oil brings forth not only the sought-after fuel but also a substantial byproduct in produced water—between 6-10 barrels of water for every barrel of crude oil. This translates to a staggering daily output of 600-1000 million barrels of water, equivalent to 160 billion litres every single day.

This is no ordinary water. Over the course of millions of years, this water has intimately interacted with diverse minerals in the reservoir. As a result, it emerges as a mineral-rich solution, with Total Dissolved Solids levels reaching an impressive saline concentration of 37%, making it 10 times saltier than seawater.

The richness of this water goes beyond mere salinity; a comprehensive exploration of its composition reveals a near-complete representation of the periodic table. Virtually every element can be found dissolved within, albeit in varying concentrations.

It's noteworthy that while the salinity of produced water can indeed surpass that of seawater by tenfold, the concentration of ions doesn't necessarily follow the same pattern. In some instances, especially concerning critical minerals, the concentration can be up to 6,000 times higher than that found in seawater.

This underlines the untapped potential and significance of oil and gas-produced water as a valuable resource with diverse applications awaiting exploration and exploitation.

Oft-overlooked byproduct

Remarkably, the mineral-rich water we have discussed has, throughout history, suffered from a surprising oversight. Faced with technological constraints and, perhaps, a lack of foresight, this invaluable resource has predominantly been treated as a mere byproduct, carelessly disposed of back into reservoirs or oceans without any extraction or treatment.

The historical neglect of this water stems from a combination of factors. First and foremost, technological limitations in the past hindered the efficient extraction and utilisation of the mineral content within the produced water. The focus was primarily on the extraction of crude oil, with little consideration given to the untapped potential flowing alongside it.

Moreover, there existed a prevailing mindset that regarded this water as an ancillary concern rather than a valuable resource in its own right. The disposal of the water back into reservoirs or oceans was seen as a convenient and expedient solution, especially in the absence of technologies capable of harnessing its mineral wealth.

This oversight, however, needs to gain attention in light of advancing technologies and a growing awareness of the finite nature of Earth's resources.

As we reassess our approach to resource utilisation, there is a burgeoning realization that this once-dismissed water holds immense promise and economic value. The shift towards recognising and harnessing the mineral potential of produced water could marks a crucial turning point in our quest for sustainable resource management and underscores the importance of revisiting overlooked resources with fresh perspectives and innovative solutions.

Abundant supply

The benefits derived from tapping into this particular source are manifold. Firstly, the sheer abundance of this water, distributed generously across numerous nations, guarantees a substantial and consistent supply. Shifting our attention from the distant realms of space or the deep ocean to this terrestrial resource holds the promise of addressing numerous environmental and economic concerns. Not only does it provide a pragmatic solution to resource availability, but it also presents an opportunity for sustainable development grounded in the wealth of this readily accessible and ample source.

Fulfilling this visionary objective demands a collective and focused endeavour. The scientific community must embark on a journey of innovation, diligently working towards the creation of novel extraction techniques tailored to this distinctive medium. As the properties of this water differ significantly from conventional sources, the development of specialised methods becomes imperative to unlock its full potential.

Simultaneously, the onus lies on federal agencies and private sectors to take up the mantle of leadership in this pioneering effort. By championing and generously funding research in this direction, these entities play a pivotal role in fostering the evolution of technologies geared toward harnessing the wealth concealed within the byproducts of the oil and gas industry. Recognising the potential impact on global mineral supply chains, these stakeholders must actively engage in supporting the scientific community's endeavours.

In summary, the captivating prospects offered by outer space and the ocean's depths are undeniably intriguing. However, amidst the grandeur of interstellar exploration and the mysteries of the deep sea, a pragmatic and potentially transformative solution may be lying in the often-overlooked byproducts of our current industrial processes. 

Texas A&M University researcher Dr. Hamidreza Samouei is undertaking research into the potential to recover critical minerals from produced water.