Aqueous Rare Earth Elements, Concentration, and Stable Isotopes in Deep Basin Brines, Wyoming
Tuesday, March 21, 2017: 2:00 p.m.
Charles Nye
,
Carbon Management Institute, University of Wyoming, Laramie, WY
Scott Quillinan
,
Carbon Management Institute, University of Wyoming, Laramie, WY
Ghanashyam Neupane
,
Idaho National Laboratory, Idaho Falls, ID
Travis McLing
,
Idaho National Laboratory, Idaho Falls, ID
Aqueous Rare Earth Elements (REEs), stable isotopes, and aqueous geochemistry where quantified in 40 Wyoming deep basin brine water samples from oil and gas (O&G) wells spanning four geologic basins. Measurement of REEs at the ng/L level in high-interference brines was possible thanks to the methods developed by INL co-authors. Isotope, geochemical, and trace analyses were performed at UW and by commercial laboratories.
These deep groundwaters are characterized by their: major ions (sodium-chloride and sodium-carbonate), novel trace-element geochemistry, isotopic shift to the right of the Global Meteoric Water Line (ranging from -87 to -39‰ for δD and -7 to +2‰ for δ18O), and also aqueous REE patterns. All sampled groundwater exhibits similar light REE behavior, but REEs heavier than europium exhibit at least two distinct styles of enrichment. Investigation of these diverse heavy REE behaviors is ongoing, but preliminary results suggest that gadolinium may record the depositional environment of the host aquifer.
The identified chemistry, stable isotopes, and especially the aqueous REE patterns may offer an opportunity to trace deep groundwater flow systems, and study aquifer-scale processes. The REEs are of particular interest as they offer a potential resource to support continued study of saline groundwater, and co-produced groundwater.
In addition to the above possibilities for tracing flow and characterizing deep groundwater. The study includes assessment of water-rock interaction and microbial involvement. The stable carbon isotopic ratios show evidence of microbial activity at some sample sites with ranges from -16.8 to 9.8‰ for δ13C. The above δD and δ18O data suggests prolonged water rock interaction at elevated temperatures, which agrees with the recorded temperatures exceeding 150˚C in some samples.
Future work will allow further characterization of these waters, identification of additional naturally occurring tracers, and improved interpretation of anomalies in REE patterns.
Charles Nye, Carbon Management Institute, University of Wyoming, Laramie, WY
Charles Nye is Research Scientist for the Carbon Management Institute (CMI) at the University of Wyoming. In his 5 years of analytic and geologic research experience he has studied uranium in-situ mining, industrial waters, and is currently studying rare earth elements. His work includes experimental design, geochemical reactions, isotope groundwater tracing, and beneficial use of waters.
Scott Quillinan, Carbon Management Institute, University of Wyoming, Laramie, WY
Quillinan received a B.S. and M.S. in Geology from the University of Wyoming focusing in isotope geochemistry. Currently, he is a licensed professional geologist and research scientist at the University of Wyoming, Carbon Management Institute. Before coming to the University, Quillinan spent seven years as a project geologist with the Wyoming State Geological Survey. His recent research focuses on the intersection of energy resource production and groundwater resources. Quillinan has worked on groundwater challenges associated with the production of coal, coalbed methane, oil and gas (hydraulic fracturing), and CO2 sequestration; including estimating and identifying water/rock geochemical reactions, groundwater tracing, confined and unconfined aquifers, efficient reservoir dewatering techniques, and potential beneficial use for produced waters.
Ghanashyam Neupane, Idaho National Laboratory, Idaho Falls, ID
To be added.
Travis McLing, Idaho National Laboratory, Idaho Falls, ID
To be added.
