Patagonia Lithium Confirms High Porosity and Pumping Capacity at Formentera Well Six

Exceptional Porosity and Specific Yield Measurements from Well Six

Patagonia Lithium Ltd (ASX:PL3) has announced the completion of detailed borehole magnetic resonance (BMR) gamma surveys at Well Six within its Formentera Lithium Brine Project in Argentina. The survey revealed an average total porosity of 22% across a 462-metre logged interval, with maximum values reaching 39%, which the company describes as outstanding. The specific yield (Sy), representing the drainable porosity relevant for production, averaged 8% and peaked at 31% in the key Zone 7.

These porosity metrics are significant because they directly influence the volume of recoverable lithium-bearing brine. The high Sy values suggest that Well Six’s aquifer has excellent potential for sustainable extraction, supporting the company’s ongoing resource development efforts.

Lithium Concentration and Aquifer Characteristics

Brine samples from Well Six returned a lithium concentration of 412ppm, exceeding previous project averages and reinforcing the prospectivity of the Formentera deposit. The brine zones were identified below 88 metres depth, with resistivity measurements averaging 1.21 Ohm.m, consistent with lithium brine characteristics.

The aquifer is stratified into eight zones based on lithology and geophysical data, with main productive aquifers identified in Zones 3, 4, 5, and 8. The gravel layer (Zone 5) exhibits the highest hydraulic conductivity (approximately 20 m/day), contributing most significantly to the aquifer’s transmissivity and pumping capacity.

Sustainable Pumping Rate and Production Potential

Using aquifer parameters derived from the BMR survey and hydraulic conductivity data, Patagonia Lithium estimates a sustainable pumping rate of approximately 160,000 litres per hour from an 8-inch diameter well at Well Six. This rate is based on a low drawdown scenario and a typical basin radius of influence of 300 metres.

The company notes that the well itself is not the limiting factor for flow rate; the aquifer’s transmissivity, estimated at around 1000 m²/day, governs sustainable extraction. Theoretical calculations suggest the aquifer could support even higher flow rates with increased drawdown, indicating robust production potential.

Implications for Mineral Resource Estimate and Future Work

Executive Chairman Phillip Thomas highlighted that the BMR porosity results will have substantial implications for the upcoming Mineral Resource Estimate (MRE) update. These findings confirm the high flow rates observed in pump tests and provide a solid foundation for production well hydrology modelling.

This announcement builds on previous positive drilling and assay results at Formentera, including lithium assays up to 412ppm and strong pump test outcomes reported in recent months. The company’s prior resource estimate, lodged in July 2025, reported a lithium carbonate equivalent (LCE) resource of 551,400 tonnes, comprising both Indicated and Inferred categories.

Further work planned includes additional drilling, seismic surveys, and gamma porosity studies to refine geological understanding and resource confidence. These efforts align with the company’s strategy to progress towards demonstration plant production, with four production wells spaced approximately 300 metres apart projected to support a nameplate production of 1,000 tonnes lithium carbonate.

Patagonia Lithium’s recent progress, including the strong porosity and lithium assay results from Well Six, complements earlier positive findings such as those from Well JAM 25-05, which showed core porosity values exceeding regional averages and lithium concentrations between 156ppm and 219ppm, supporting potential MRE expansion Patagonia Lithium Reports Strong Porosity and Lithium Assay Results from Formentera Well, Supporting MRE Expansion.