Smackover Formation’s 5+ Million Tons Could Exceed Global Demand
A potential “game-changer” lithium reserve has been discovered in southwestern Arkansas, says a recent US Geological Survey (USGS) study.
There are an estimated 5 million to 19 million tons of lithium reserves in the Smackover Formation, a Jurassic-era limestone and dolomite area that stretches across six states from Texas to Florida.
If commercially harvested from the Smackover oilfield brines, the lithium would contribute greatly to US domestic energy resources, the USGS said. “Using these predicted lithium maps with reservoir parameters and geologic information, we calculated that there are 5.1 to 19 million tons of lithium in Smackover Formation brines in southern Arkansas, which represents 35% to 136% of the current US lithium resource estimate,” wrote Katherine J. Knierim, lead author of the USGS study published in Science Advances in September.
The discovery also has global implications.
“The low-end estimate of 5 million tons of lithium present in Smackover brines is also equivalent to more than nine times the International Energy Agency’s projection of global lithium demand for electric vehicles in 2030,” the USGS said.
According to Statistia.com, global demand for lithium is projected to rise “from 720,000 metric tons in 2022 to 3.1 million metric tons” in 2030. Much of this growth is due to the market for electric vehicles batteries.
The new lithium discovery, which was done using a combination of water testing and machine learning, was described as a “treasure trove,” by industry newsletter Supply Chain Dive. It could also be “a game changer” for the US domestic production of lithium, the newsletter said.
Currently, 60% of the world’s lithium is produced in Chile, Argentina, China, and in Nevada’s Clayton Valley in the US. Currently, the US relies on imports for more than 25% of its lithium.
Lithium and Brine
According to the study, the Smackover lithium reserves are dissolved in brine at concentrations as great as 400 milligrams of lithium per liter of brine, or more. The lithium was brought to the surface within brines that were produced as waste streams from oil, gas, and bromine operations. The researchers calculated that 5,000 tons of dissolved lithium were brought to the surface within brines in 2022, citing the opportunity of potentially extracting a valuable commodity from a waste stream.
Though lithium recovery technologies from brines are still in the testing and implementation phase, Metal Tech News reports that Mobil Lithium (a division of ExxonMobil), Albemarle Corp. (the world's largest lithium producer), and Standard Lithium Ltd (a US Department of Energy grant recipient for its South West Arkansas lithium project), are all working to develop the commercialization of direct lithium extraction technology.
"We have the technology that can extract lithium with fewer carbon emissions,” said Patrick Howarth, lithium global business manager at ExxonMobil Low Carbon Solutions.
Stanford Direct reported in August 2024 that Stanford University researchers had developed a lithium extraction method that promises to be far cheaper and more environmentally friendly than current brine extraction methods using drying ponds.
The USGS Study Backstory
In the USGS-led study, the researchers used “published and newly collected brine lithium concentration data” to train a “random forest machine-learning model” and create a continuous spatial map of predicted lithium in Smackover Formation brines. These were then used “with geologic and reservoir characteristics—such as formation thickness, porosity, and water-to-oil ratios” to calculate the mass of lithium in the brines.
Prior to the USGS-led study, scientists were already aware of the presence of lithium in oil field brine waste streams at various concentrations and volumes at locations within the Marcellus Shale in Pennsylvania, for instance, and were aware that using machine-learning models trained with “explanatory” geologic variables might help predict groundwater chemistry.
There had also been investigations into how brine geochemistry can help predict lithium in the Smackover Formation, but, according to the USGS-led team, that investigation had “only predicted lithium at brine sample locations.”
According to the team, two of the five most important variables for predicting lithium in Smackover brines were dissolved hydrogen sulfide (H2S) concentrations in the brines and the depth of the brine samples.
They said other geologic information may become important for predicting lithium quantities and can be tested in future modeling efforts.
Sources:
https://www.sciencealert.com/a-giant-hidden-source-of-lithium-was-just-discovered-in-arkansas
https://www.sciencealert.com/a-vast-untapped-source-of-lithium-exists-in-the-us
https://www.usgs.gov/media/images/lithium-smackover-formation
https://pdfs.semanticscholar.org/21fd/b1311d417523bd7e4fcd70bca39573688d23.pdf
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