Patagonia Lithium has corrected its Well 8 announcement, confirming a 72-hour pumping rate of about 2,043 litres per hour and rapid aquifer recovery at its Cilon project in Argentina. The pumped brine is estimated to have contained 29kg to 33.7kg of lithium, although the figure is an inferred assay-based estimate rather than a resource or production measure.
- 2,043 litres per hour sustained over 72 hours
- 146,800 litres of brine extracted from 485m Well 8
- Preferred estimate of 30kg lithium, equivalent to 159kg LCE
- Aquifer recovered from 52.4m to 3.64m in 24 hours
- Well 9 completed a successful packer test at 150m
Well 8 sustains 2,043 litres per hour
Patagonia Lithium Ltd (ASX:PL3) has confirmed a strong sustained flow from Well 8 at its Cilon concession, extracting 146,800 litres of brine during a 72-hour constant-rate pump test. The reported flow rate was approximately 2,043 litres per hour, although the detailed statistics also cite 2,042 litres per hour, a discrepancy the company has not explained.
Rapid recovery supports aquifer performance
The more striking result may be what happened after pumping stopped. Water levels fell from a starting level of 3.64 metres to about 52.4 metres during the test, then recovered to 3.64 metres within 24 hours. Patagonia said the recovery demonstrated strong aquifer performance near the surface, rather than only at depths of 300 or 400 metres.
The result builds on the earlier Well 8 porosity results, which reported 15% total porosity and 5.9% drainable specific yield from one core result, while noting that the pump test and additional porosity work were still outstanding at the time.
Lithium estimate depends on mixed brine samples
Brine was pumped from 477 metres in Well 8, while the closest packer sample was taken at 330 metres and assayed at 232 milligrams per litre of lithium. Packer assays from 280 to 330 metres ranged from 218mg/L to 230mg/L. Because the 72-hour pumping process mixed brine from different intervals, Patagonia has used a broader assumed range of 200mg/L to 230mg/L for the extracted volume.
That produces an estimated 29kg to 33.7kg of contained lithium, with a preferred figure of 30kg, or 159kg of lithium carbonate equivalent. The company has not presented this as a mineral resource, reserve or production forecast. It is an estimate of the lithium in the brine volume recovered during this particular test, and remains sensitive to the assumed concentration range and mixing during pumping.
Well 9 adds another successful test
Well 9 has completed a successful packer test at 150 metres, with the hole ending at 230 metres. At Well 8, Patagonia identified a sandy interval between 226 metres and 324 metres as a particularly interesting aquifer zone, supported by 20 core samples, 10 positive packer tests and further porosity analysis still being processed by DBS&A and BMR.
Resource update remains the next test
Patagonia said additional processing of spectral gamma geophysics increased specific-yield porosity by 2% across all six lithological zones. Four more core samples are being processed for porosity correlation, while an updated Mineral Resource Estimate is being prepared and a scoping report is planned. The technical progress is encouraging, but the commercial significance will depend on how these flow results, brine chemistry and porosity data translate into a larger and more confident resource base.
Bottom Line?
The pump test strengthens the technical case for Cilon, but the 30kg lithium figure describes one mixed test volume, not an indication of mineable inventory. The pending porosity work and updated resource estimate will determine whether strong well performance can be demonstrated across the project.
Questions in the middle?
- Will the additional core and BMR results confirm the higher specific-yield interpretation across all six zones?
- How will the updated Mineral Resource Estimate treat the rapid recovery and variable brine chemistry observed at Well 8?
- Can Well 9 replicate the flow and lithium characteristics seen in the deeper Well 8 aquifer intervals?