Controls on lithium content of oilfield waters in Texas and neighboring states (USA)

Abstract

The amount of lithium (Li) required to support the energy transition underscores the need to develop Li sources beyond the traditional hard-rock mining and surface continental brines. The objective of this study was to explore the potential for Li production from oilfield waters in the U.S. Gulf Coast region. Data on Li concentrations were obtained from ~2450 formation water samples taken in states along the greater Gulf Coast (NM, TX, OK, LA, AR, and MS). The dataset contains geochemical analyses that spans >70 years, including the USGS database (v2.3), compilation of recent data previously published by the authors, analyses from recently collected samples and from archived samples, and data from U.S. Bureau of Mines reports.Aqueous Li distribution is lognormal, typical of trace elements, with background levels in the 0–20 mg/L range. High concentrations (≥80 mg/L) are restricted to some intervals at certain locations: Jurassic Smackover Formation, a well-known brine deposit in Arkansas (300+ mg/L Li), but also along the Gulf Coast in Texas, Louisiana, and Mississippi (several samples ≥100 mg/L Li); Permian and Pennsylvanian Granite Wash in the Anadarko Basin of Texas (several samples >100 mg/L Li) (not confirmed); and Cretaceous Edwards Formation of South Texas (several samples ≥100 mg/L Li). Genetic models for Li enrichment are lacking, but high Li seems to be related to the noted fact that Li concentrations increase with depth and with total dissolved solids. Other common characteristics of high-Li brines in the Gulf Coast are high K, Ca, and B, which reflect water-rock interactions, presence of major faults, and association with higher permeability intervals that can spread Li-bearing fluids. Host rocks for high-dissolved Li brines commonly are carbonates, possibly because of their limited sorption opportunities. Close connection to an igneous basement or to a depositional environment that supported accumulation of surface continental brines does not seem to be required.