CDL Blog

Geoscience BC and Canadian Discovery Ltd. (CDL) published the NEBC Lithium – Formation Water Database on February 29, 2024. Lithium is on Canada’s Critical Minerals List and will play a significant role in our country’s move to a net-zero emissions economy as it is a key component of rechargeable vehicle batteries.

The study’s primary goal was to better understand the distribution of lithium in the subsurface in northeastern BC (NEBC) by sampling, analyzing and interpreting saline water (brine) samples from existing hydrocarbon-producing wells (figure 1). It also delves into brine evolution and potential lithium-enrichment mechanisms. Prior to this study’s completion, limited lithium data and knowledge were publicly available for BC, and this body of work plays a foundational role in supporting the lithium industry’s potential development.

The geology of NEBC is similar to that of Alberta and Saskatchewan where lithium brine data are publicly available and several lithium extraction projects are underway. The database (including data, report, maps and shapefiles) can be downloaded from the Geoscience BC website; the link is in the references.

A total of 133 samples were obtained throughout NEBC in a number of different formations, although heavily weighted toward the Montney. These data were supplemented by data from the Geological Survey of Canada and the Alberta Geological Survey. Lithium concentrations in NEBC ranged from negligible to 100 mg/L. Lithium concentrations exceeding 50 mg/L are currently deemed as economically interesting by industry given the current state of direct lithium extraction (DLE) technologies.

Significant lithium concentrations are found in the Montney, with the Blueberry/Gundy, Groundbirch and Parkland/Doe areas having the highest concentrations (figure 2). Within the Montney, CDL estimates a brine-hosted in situ lithium carbonate equivalent (LCE) potential of 9.8 million tonnes with an average concentration of 56 mg/L over an area of 32,000 km² (figure 3). The Montney in this area is not an aquifer; it is an unconventional, overpressured, low porosity and low permeability gas-bearing reservoir that is quite desiccated in some areas and, therefore, has low water production (compared to aquifer formations like the Belloy). CDL reviewed the distribution of Montney water production and found that areas of higher water production do not necessarily coincide with high lithium concentrations. Given the challenges of ensuring large sustained flowrates of water from the Montney, CDL’s assessment is that it is not feasible to produce Montney lithium brines on a standalone basis at this time; these brines must be co-produced with natural gas to be economic.

Given the scarcity of data over all formations, including the Montney, CDL researched proxies that are readily available from routine water analyses, which can then be used to infer lithium concentration. Several candidates emerged including potassium, calcium, magnesium and total dissolved solids (TDS). Further investigation showed a strong correlation between TDS and lithium with a value of 150,000 mg/L (also ppm) TDS corresponding to a lithium concentration of 30 mg/L. This correlation was used in mapping the Montney and other formations to suggest areas where there could be economic concentrations of lithium, despite the lack of lithium data.

Based on the TDS proxy analysis, there could be potential for the Slave Point, Keg River, Belloy and Halfway formations to host economic concentrations of lithium. These formations are aquifers and inadequate water production should not be an issue like in the Montney. There were not sufficient data in these (or other) formations to calculate a brine-hosted in situ lithium potential resource with any confidence.

During the research for this study, it was observed that process of seawater evapoconcentration alone is not adequate to account for the lithium concentrations observed in the Montney in NEBC. Other potential sources of lithium-enrichment were/are volcanically sourced clay minerals that underwent ion-exchange during illitization (water-rock interactions), temperature effects due to burial, and water-rock interactions between hydraulic fracturing fluids and the host rock (figure 4). These lithium-enrichment mechanisms are rich fodder for another blog!

Despite the advances made in this study, all formations in NEBC are under-sampled with respect to lithium. Two of the recommendations are that further sampling for lithium should be undertaken in all formations, and that lithium should be added to routine water analyses.

This database was sponsored by Geoscience BC, Northern Development, Natural Resources Canada and LithiumBank, while the research (designing the brine sampling program, collecting the samples, and analyzing and interpreting the data) was undertaken by Matrix Solutions Inc. and Canadian Discovery Ltd.

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