Prominence Energy Defines 203 Bscf Hydrogen and 9.2 Bscf Helium Prospective Resource at Eyre

Prominence Energy has established its first independently assessed Prospective Resources at the Eyre Project in South Australia, with RISC Advisory estimating 202.8 Bscf of hydrogen and 9.2 Bscf of helium on a 2U, or P50, gross unrisked basis. 

The assessment provides the first independent quantification of Prominence’s identified exploration portfolio at Eyre and covers 15 leads across multiple geological plays. At the higher 3U case, aggregate gross unrisked Prospective Resources increase to 491.6 Bscf of hydrogen and 32.3 Bscf of helium. 

The lower 1U case is estimated at 70.1 Bscf hydrogen and 1.7 Bscf helium. On a risked basis, which incorporates RISC’s assessed geological probability of success, the 2U estimates fall to 20.4 Bscf hydrogen and 0.9 Bscf helium. Hydrogen at the 2U unrisked level is equivalent to approximately 470,849 tonnes. 

The distinction between the unrisked and risked numbers is important. RISC has assigned individual leads geological probabilities of success ranging from 8% to 12%, reflecting the frontier nature of natural hydrogen exploration and uncertainty around whether the required source, reservoir, trap and seal elements combine into working subsurface systems. 

The Prospective Resources also relate to undiscovered accumulations. They are not reserves or Contingent Resources and do not represent evidence that a hydrogen or helium discovery has been made. Exploration drilling will be required to test whether the modeled accumulations exist and whether potentially recoverable gas is present. 

What the independent assessment does provide is a quantified framework for deciding where Prominence should drill. 

Rather than concentrating the prospective resource in one large target, Eyre contains a portfolio spanning Eocene channel and sandstone plays, fractured granite basement targets and fractured sandstone targets. Six of the assessed leads contain stacked exploration objectives, potentially allowing a single drilling location to investigate more than one prospective horizon.  

Several targets are individually material within the overall resource estimate. 

The largest identified 2U unrisked objective is Lead 2_15, with an estimated 33.0 Bscf hydrogen and 1.50 Bscf helium. Lead 3_2 contains an estimated 24.2 Bscf hydrogen and 1.11 Bscf helium, while the Eocene sandstone objective at Lead 2_7 is estimated at 20.1 Bscf hydrogen and 0.89 Bscf helium. 

Lead 2_2’s Eocene sandstone objective contributes another 19.1 Bscf hydrogen and 0.84 Bscf helium, while Lead 3_1 contains an estimated 17.2 Bscf hydrogen and 0.78 Bscf helium. Together, those five objectives account for approximately 56% of the aggregate P50 hydrogen and helium resource, leaving the remainder distributed across the broader portfolio. 

That distribution could give Prominence greater flexibility when designing its first drilling campaign. Targets can now be ranked not simply on estimated size, but on geological evidence, probability of success, potential stacked objectives, drilling efficiency and operational considerations. 

RISC’s work builds on multiple datasets assembled across Eyre, including Prominence’s soil-gas sampling, Sentinel-2 satellite studies, gravity and magnetic inversion, structural interpretation and South Australian Government mineral, groundwater and geological information. The assessment considers Hiltaba and Seaward suite basement granitoids within the acreage as viable potential source rocks. 

Prominence is now moving from resource definition into drill-target selection, engineering and preparations for a potential farm-out ahead of a targeted multi-well drilling campaign in mid-2027. 

An updated drilling engineering and cost assessment is scheduled for October, alongside the planned commencement of the farm-out process. Detailed design and planning for the drilling campaign are expected through November and December. 

The relatively shallow nature of the Eyre targets could also influence the economics of the exploration program. Preliminary company estimates indicate approximately A$5 million could potentially fund three exploration wells, or two wells plus additional seismic, although updated engineering and cost estimates are still required. 

A farm-out or strategic partnership could provide another route to financing the program while reducing Prominence’s direct capital exposure. The independent resource assessment gives potential partners a third-party framework through which to evaluate the scale and geological risk of the opportunity. 

Eyre is also only the first of two resource assessments planned across Prominence’s broader South Australian position. 

The company is targeting completion of an independent Prospective Resources Review for Northern Hinge by the end of September, following finalisation of its Native Title Land Use Agreement. Eyre and Northern Hinge form part of Prominence’s approximately 64,000-square-kilometre South Australian helium and natural hydrogen portfolio. 

Full press release can be found here.