Patagonia Lithium Delivers Strong Well 8 Pump Test Results Ahead of MRE Update
Key Takeaways
- Well 8 (JAM-26-08) at the Cilon concession achieved a sustained flow rate of 2,043 L/hour over 72 hours, extracting 146,800 litres and approximately 180 kg LCE during the test.
- Aquifer recovery was exceptionally fast — water levels rebounded from 52.4 m back to 3.64 m depth within 24 hours of pumping ceasing, signalling a highly permeable, well-connected system operating near the surface rather than at depths of 300–400 m.
- Lithium concentration at 250 m depth measured 232 mg/L, consistent with the existing MRE grade of 294 mg/L across the broader 551,400 t LCE resource.
- A well-sorted sandy horizon between 226 m and 324 m depth, 20 core samples, and 10 positive packer tests add to the technical dataset underpinning the forthcoming MRE update and scoping report.
- Well 9 has already completed a successful packer test at 150 m depth, confirming the drilling program continues to advance systematically across the 19,500 ha project area at Salar de Jama.
Well 8 delivers strong 72-hour pump test results at Cilon
Patagonia Lithium (ASX: PL3) has completed a 72-hour constant-rate pump test on Well 8 (JAM-26-08) at its Cilon concession within the Formentera/Cilon project, Salar de Jama, Jujuy Province, Argentina. The test achieved a flow rate of 2,043 L/hour, extracting a total of 146,800 litres over the pumping period.
The test was designed to determine the hydraulic performance of the aquifer, with results described by the company as consistent with its other proximate wells. The standout result was aquifer recovery: after pumping ceased, water levels returned from 52.4 m to 3.64 m depth within 24 hours, a strong indicator of aquifer quality.
The static water level at the start of the test was 3.64 m depth, falling to 52.7 m depth by the end of the 72-hour pumping period.
Phillip Thomas, Executive Chairman
“We achieved strong pumping results from well 8 on the Cilon concession. The recovery, after pumping finished, was exceptionally fast. The water level measured at start was 3.64m and after the pump was shut down was 52.7 m depth showing the aquifer performs very well near the surface not at 300 or 400m depth.”
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What pump testing tells lithium brine investors
A 72-hour constant-rate pump test is one of the most reliable ways to assess how an aquifer will actually behave under sustained extraction conditions. Rather than relying on theoretical modelling, the test pumps the well at a fixed rate for three continuous days, measuring real-world flow, how far water levels drop during pumping (called drawdown), and how quickly they recover once pumping stops.
For a lithium brine project, each of these metrics carries direct commercial weight. Fast recovery after pumping signals a highly permeable, well-connected aquifer, meaning the system can replenish itself efficiently. That matters for extraction economics because shallower, high-performing aquifers are generally cheaper to operate than deep ones. The company noted the aquifer performs well near the surface, rather than at depths of 300 m or 400 m.
The announcement also references approximately 180 kg LCE pumped during the test. LCE stands for lithium carbonate equivalent, the standard industry unit used to express lithium content in terms of the finished battery-grade chemical. It allows investors and analysts to compare exploration results on a common basis. For a junior explorer like Patagonia Lithium advancing toward a resource update, metrics like flow rate, aquifer recovery speed, and LCE yield from pump tests are meaningful indicators of how a deposit might perform at scale.
Lithium concentrations and aquifer characteristics confirm Cilon’s potential
The key technical results from Well 8 are summarised below.
| Metric | Result |
|---|---|
| Flow rate | 2,043 L/hour |
| Total volume extracted | 146,800 litres |
| Lithium concentration | 232 mg/L at 250 m depth |
| Lithium pumped during test | ~34 kg Li / ~180 kg LCE |
| Aquifer recovery | 52.4 m → 3.64 m within 24 hours |
Additional technical findings from the well program include:
- A well-sorted sandy horizon identified between 226 m and 324 m depth, noted for favourable porosity and permeability properties
- 20 core samples recovered for total and effective porosity determination in the laboratory
- 10 positive packer tests conducted at different depths, allowing brine sample collection for hydrogeochemical characterisation
Well Six porosity results at Formentera recorded 31%, establishing a benchmark of aquifer quality that subsequent wells in the program have continued to meet or exceed.
Packer tests involve isolating sections of the wellbore using inflatable seals (packers) to extract brine samples and measure flow from specific depth intervals.
- BMR spectral gamma geophysics reprocessed at 15ms increased specific yield porosity by a further 2% across all six zones
- 4 additional cores are being processed by DBS&A, with BMR porosity results still pending
In a sign of broader program momentum, Well 9 has also completed a successful packer test at 150 m depth.
Well 7 brine results at Formentera similarly showed strong hydrogeochemical characteristics, reinforcing the pattern of consistent aquifer performance across the sequential drilling program at Salar de Jama.
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What’s next for Patagonia Lithium
A Mineral Resource Estimate (MRE) update is currently being computed, with a scoping report to follow. The existing MRE, released on 14 July 2025, stands at 551,400 t LCE @ 294 mg/L, comprising 14,800 t LCE @ 393 mg/L Indicated and 536,600 t LCE @ 292 mg/L Inferred.
Well 8 is part of the ongoing drilling program at Cilon since the company listed on 31 March 2023, reflecting a systematic drilling programme across a project area spanning 19,500 ha at Salar de Jama. The Well 8 pump test results, alongside ongoing core processing and geophysics work, contribute to the dataset underpinning the forthcoming MRE update.
Investors seeking more frequent updates, including videos and commentary from Executive Chairman Phillip Thomas, can visit the company’s website and the Executive Chairman blog at patagonialithium.com.au.
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