Highlights

  • Vulcan reported its first brine reinjection test into the sandstone reservoir matrix at the Lionheart lithium and renewable energy project.
  • Well LSC-3a was the seventh well included in the planned 28-well field development programme.
  • The measured surface injection rate was about 35 standard litres per second at the reported test conditions.
  • A modelled injection capacity of approximately 64 standard litres per second under planned operating conditions exceeds the field plan assumption of about 40.
  • The findings are based on one well and do not establish commercial production, project returns or revised financial guidance.

Vulcan Energy Resources Limited (ASX:VUL) is developing an integrated lithium and renewable energy project in the Upper Rhine Valley of Germany. On 15 October 2026, Vulcan Energy Resources (ASX:VUL) announced injection test results from well LSC-3a at Project Lionheart. The test was designed to examine whether lithium-depleted brine can be returned directly to the sandstone reservoir matrix, an approach distinct from the fault-zone injection used in earlier wells.

The Significance of the Lionheart Well

LSC-3a is a horizontal well with a total measured depth of 3,743 metres. It was drilled in September 2026 by the company’s in-house drilling operation and tested in early October. The well represents the seventh well associated with the planned 28-well Lionheart Field Development Plan, including four existing wells and three new wells. The pilot hole identified a relatively permeable reservoir interval also observed in nearby wells.

Observed Injection Compared With Modelled Capacity

During the test, Vulcan measured a surface injection rate of approximately 35 standard litres per second at a wellhead pressure of 69 barg and temperature of 18°C. Those are the reported test conditions. The company separately interpreted injection capacity of about 64 standard litres per second at a planned operating wellhead pressure of 70 barg and temperature of 65°C, using test data, downhole measurements and wellbore modelling.

The distinction matters. The higher 64-litre figure was not directly measured at those operating conditions. Vulcan Energy Resources (ASX:VUL) said its Field Development Plan assumes roughly 40 standard litres per second for matrix-injection wells. The comparison therefore supports the company’s confidence in its engineering assumptions, while leaving uncertainty about sustained performance during operations.

How the Results Feed Into Reservoir Planning

The company said matrix injection provides additional flexibility alongside its planned fault-zone reinjection wells. Its reservoir interpretation draws on seismic reprocessing, drilling, logging, core analysis and testing. Vulcan believes these datasets support the continuity of a higher-permeability interval across more than one well and help improve decisions about well placement and the balance of injector types.

Further validation will come from new wells rather than from extrapolating one result across the field. Vulcan Energy Resources (ASX:VUL) intends to incorporate LSC-3a into its integrated geological and dynamic reservoir models and use the findings to guide the next reinjection wells, LSC-4 and LSC-5. Results could vary because reservoir properties are not uniform.

Production Ambitions and Project Limitations

Lionheart has a stated target of 24,000 tonnes of lithium hydroxide monohydrate annually, alongside renewable power and heat outputs. These are company project targets, not production achieved by the new well. The October disclosure does not announce additional financing, revised project economics, commercial lithium output or a new development schedule. Its focus is narrowly on reservoir testing.

Key Insights

The LSC-3a findings provide technical evidence supporting the matrix reinjection design at Lionheart. The measured rate and the higher modelled operating capacity should be assessed separately. For Vulcan Energy Resources (ASX:VUL), forthcoming results from additional injectors and updated field modelling will be important for determining whether the observed single-well performance translates into a reliable project-wide system.