D3 Energy’s RBD10 Well Surges 38%, Revealing Rare Reservoir Recharge

Unique Reservoir Dynamics Confirmed

D3 Energy Limited (ASX, D3E) has delivered a compelling update from its ER315 permit in South Africa’s Free State, where the RBD10 well has been re-tested with striking results. The well flowed at an average rate of 264 million standard cubic feet per day (Mscfd) over a 14-day period, marking a 38% increase from the initial test conducted last year. This improvement not only highlights the reservoir’s exceptional characteristics but also signals a potentially transformative impact on the project’s economics.

Unlike conventional reservoirs where pressure and flow rates typically decline after initial production, RBD10 has demonstrated an unusual pressure increase during shut-in periods. This phenomenon points to continuous recharge of helium and biogenic methane from deep source rocks, a feature that Managing Director David Casey describes as “once in a career.” The sustained recharge suggests a long-term equilibrium where production can be maintained with minimal decline, a rarity in the energy sector.

Implications for Development and Costs

The improved flow rates at RBD10, alongside a recent 32% increase at the nearby RBD03 well, indicate stronger reservoir connectivity and deliverability than initially anticipated. This enhanced performance means wells can be spaced further apart, reducing the total number of wells required to meet production targets. Fewer wells translate directly into lower drilling and development costs, improving the project’s capital efficiency and potentially accelerating timelines.

Such reservoir behavior is attributed to an extensive fault system facilitating the migration of gases from deep formations to the surface. The ongoing recharge mechanism could lead to slower production declines, offering a steadier supply profile and greater operational flexibility. This sets ER315 apart from typical gas projects, positioning D3 Energy as a notable player in the helium and natural gas markets.

Strategic Outlook and Next Steps

While the results are encouraging, the company acknowledges that an eventual balance between recharge and production will be reached, though this appears distant given historical evidence of boreholes drilled decades ago still flowing steadily. D3 Energy’s focus will now be on further testing and analysis to refine development plans and confirm the long-term sustainability of these unique reservoir characteristics.

With ER315 continuing to deliver strong technical outcomes, D3 Energy is well positioned to advance its flagship asset toward commercial development. The recent acquisition of helium and hydrogen permits in Australia’s Arckaringa Basin also broadens the company’s strategic footprint in critical gases, complementing its South African operations.