Patagonia Lithium Well 8 Pumps 146,800 Litres as Aquifer Recovers in 24 Hours
Key Takeaways
- Well 8 sustained 2,043 L/hour for 72 hours and extracted 146,800 litres of brine, a result Patagonia Lithium says is consistent with its other proximate wells.
- The well recovered from 52.4m to 3.64m within 24 hours of shutdown, which management reads as proof the aquifer performs strongly near the surface.
- Management estimates 30kg of lithium, or 159kg LCE, was in the brine pumped, based on an assumed 200ppm to 230ppm rather than a direct assay.
- The correction moves the closest packer sample to 330m, where lithium assayed at 232ppm, and confirms brine was pumped from 477m.
- An updated MRE and scoping report are coming with no disclosed timelines, against an existing 551,400t LCE resource at 294mg/L.
Well 8 pump test delivers 2,043 L/hour over 72 hours
Patagonia Lithium (ASX:PL3) has issued a correction to its 2 October 2026 “Significant Pump Test Results from Well 8” release. The 9 October 2026 announcement is described as “materially unchanged” from the original, with updated information on extraction depth and the process used to test the flow rate.
The headline result holds. The 72-hour pump test on Well 8 achieved 2,043 L/hour, with 146,800 litres extracted, and the Company states the results are consistent with its other proximate wells.
Key figures from the test:
- 2,043 L/hour sustained over 72 hours, totalling 146,800 litres extracted
- Well depth of 485m
- Pump installed at 80m, with brine pumped from 477m (a corrected detail)
- Static water level of 3.64m
The announcement’s key statistics section cites an estimated flow rate of 2,042 L/h. The headline figure used throughout the announcement is 2,043 L/hour.
Phillip Thomas, Executive Chairman
“We achieved strong pumping results from well 8 on the Cilon concession. The recovery, after pumping finished, was exceptionally fast…”
For you as an investor, a pump test shows whether the aquifer can actually deliver brine at a useful rate. That supports the work on the resource upgrade, where an updated Mineral Resource Estimate (MRE) is being computed.
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Fast aquifer recovery and lithium in the brine pumped
Recovery performance
After pumping stopped, the well recovered from 52.4m to 3.64m in 24 hours, according to the Figure 3 caption, which describes this as “very strong performance”. The Chairman’s quote in the text cites 52.7m as the depth after the pump was shut down. The two figures differ slightly, and this article uses the Figure 3 caption value.
Mr Thomas said the data shows “the aquifer performs very well near the surface not at 300 or 400m depth.” That is management’s interpretation of the result.
Lithium contained in the pumped brine
The correction also fixes a sample depth. The closest packer sample was at 330m (not 250m as reported previously), where the assay was 232ppm lithium. It was the heaviest brine measured by specific gravity (SG) at 1.088, and packer assays from 280m to 330m ranged from 218ppm to 230ppm.
Because of mixing during pumping, management considers it reasonable to assume 200ppm to 230ppm for the pumped brine. These are management assumptions, not measured assays of the pumped brine itself.
On that basis, the lithium contained in the brine pumped was between 29kg and 33.7kg, with a preferred value of 30kg (159kg lithium carbonate equivalent, or LCE).
Brine results from Well 7 at Formentera had earlier pointed toward an expanded resource, giving the Well 8 lithium figures a nearby comparison point.
| Metric | Value | Note |
|---|---|---|
| Flow rate | 2,043 L/hour | 72-hour pump test |
| Volume extracted | 146,800 litres | Brine pumped from 477m |
| Packer assay at 330m | 232ppm lithium | Corrected from 250m; SG 1.088 |
| Assumed range | 200ppm to 230ppm | Management assumption due to mixing |
| Lithium contained | 29kg to 33.7kg | Preferred value 30kg (159kg LCE) |
How pump tests work and why they matter
Grade tells you how much lithium sits in the brine. It does not tell you whether that brine can be pulled out of the ground at a useful rate, which is what a pump test is designed to measure.
A constant-rate pumping test runs a pump continuously while water levels are monitored, to determine the hydraulic parameters of the well and the aquifer. A recovery test then switches the pump off and tracks how quickly the water level rises back. Fast recovery suggests the aquifer refills readily.
The Well 8 setup, as described in the announcement:
- A 3″ outer-diameter submersible pump was installed at 80m.
- A Level Logger sensor was positioned at an approximate depth of 52m, with a Baro Logger installed inside the well above the static water level.
- Brine was discharged into 18 tanks of 8,000 litres each, with fill times monitored to calculate flow rate.
- Manual drawdown measurements were taken at constant, predefined intervals during 72 hours of continuous pumping.
- The pump was then shut down for a 24-hour recovery test, with water level rise recorded at constant intervals.
The announcement describes this testing as providing more information than that acquired in the packer assay tests (which sample brine at set depths).
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Porosity, Well 9 and the next steps
Porosity measures how much open space a rock holds, which affects how much brine it can contain. Further processing of the BMR spectral gamma geophysics at 15ms increased the Specific yield porosity by a further 2% across all six lithological zones.
Separately, DBS&A is processing a further 4 cores for porosity, to be correlated with BMR porosity results yet to be received. Well 9 has completed a successful packer test at 150m, with end of hole at 230m.
Well 8 key statistics from the announcement:
- A well-sorted sandy horizon with thin levels of volcaniclastic influence was identified between 226m and 324m
- 20 core samples were recovered for total and effective porosity determination
- 10 positive packer tests were carried out at different depths
- Laboratory analyses show lithium concentrations reaching up to 232 mg/L
A Mineral Resource Estimate update is being computed, and a scoping report will follow. The announcement discloses no timelines. The existing MRE, released on 14 July 2025, stands at 551,400t LCE at 294mg/L.
On capital structure, PL3 has 327.7 shares and 82.5m quoted PL3OB options.
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