Ironically, a treasure trove of vital minerals is actually water that was previously deemed too polluted and too expensive to clean. Dr. Hamidreza Samouei, a researcher at Texas A&M University who is studying the composition of this extracted water, said this waste byproduct of oil and gas extraction contains almost every element in the periodic table, including elements of great industrial and economic importance.
His goal is to treat water in stages using unwanted carbon dioxide (CO2) to recover these valuable elements and ultimately produce fresh water for agricultural use once the treatment process is complete.
"Recognizing the potential value of production water can provide practical solutions to some of the world's most pressing environmental challenges, including carbon dioxide emissions, the increasing scarcity of certain minerals and water itself," said Samuel, a research assistant professor in the Harold Vance Department of Petroleum Engineering.
In January 2024, the Society of Petroleum Engineers' Petroleum Technology Journal published an article titled "Liquid Gold Mines: Using Carbon Dioxide to Unleash the Key Mineral Potential of Produced Water," which introduced Samuele's "produced water mining" research. He presented on this topic at the Middle East Water Week Conference and Exhibition in Saudi Arabia in December 2023, and reported his latest findings at the Produced Water Association Annual Meeting in Houston, Texas, in February 2024.
Why is produced water being dumped?
Water accumulates in underground areas where geological processes occur, such as hydrocarbon reservoirs, where it dissolves and stores large amounts of minerals and other elements. In the oil and gas extraction process, on average, for every barrel of oil extracted, six 42-gallon barrels of "produced water" are recovered. In rare cases, the ratio can even reach an astonishing 500:1.
In 2020, more than 240 billion barrels of produced water were recovered from oil and gas operations globally each year, with Texas alone recycling 33 million barrels per day. Texas’ Permian Basin oil fields produce more produced water than all other U.S. shale fields combined. Treating such large volumes of produced water is expensive, so the produced water is primarily treated as wastewater and injected into underground treatment sites for safe containment.
Uncovering the hidden value in produced water
Since all of the components in produced water have never been cataloged, Samuele's research started with the basics. He collected produced water samples from across the United States and created a standardized method for analyzing water composition. At this point, he learned that water contained nearly every element listed on the periodic table.
Samuel's discoveries include key minerals such as lithium, rubidium, cesium, gallium and platinum group metals - fundamental technologies that will power the computing, energy and transportation industries now and into the future. What's more, like other produced waters, produced water also contains less expensive but abundant amounts of sodium, potassium, magnesium and calcium - substances that can be used in manufacturing processes, fertilizer production and other industries.
All of these minerals can be much more profitable than the oil in the produced water, so water reclamation costs can be easily offset by selling the recovered minerals.
Samuel explained that while desalination of the produced water has been considered, methods of mining all the salt and minerals before treating the water have not been explored. His current research is focused on developing optimal processes to extract valuable minerals from brine in stages using carbon dioxide desalination technology, which he says is "a pioneering approach to the directional recovery of minerals from produced water. The process includes various filtration technologies, such as ultrafiltration and nanofiltration, and even utilizes reverse osmosis technology."
commercialization potential
The study is establishing a baseline for produced water extraction, whether using produced water or other salty water resources, but Samuele said further development will require funding. Government sponsors are concentrating on mining critical minerals in places like the seafloor and even asteroids, rather than in close proximity like production water.
He hopes to change the way the oil and gas industry views produced water, first as a profitable way to collect payments and then, perhaps 10 years from now, as a source of water for its own mining operations: "If we see produced water as a waste, then it may not be beautiful, but if we see it as a resource, then it will have an impact on the world for the next generation."
Compiled from:ScitechDaily