Mosman Oil and Gas (MSMN) has released the results of the independent resource evaluation for its Sagebrush project in Colorado.
Mosman holds an 82.5% working interest in Sagebrush.
The report, prepared by Sproule ERCE, confirms Sagebrush as a technically credible helium and natural gas project with substantial commercial potential.
It shows a best estimate (2U) of helium resources at 134 million standard cubic feet, with a potential gross value of US$40 million, allowing US$300 per thousand cubic feet.
The upside scenario puts the helium resource at 269 million standard cubic feet, with a valuation of around US$80 million.
There are also significant quantities of natural gas and carbon dioxide under all scenarios.
Additional value from the hydrocarbons is estimated at between US$3 million and US$10 million, with greater upside possible through power generation use.
What’s more, untested deeper Leadville intervals showed hydrocarbon indications, providing further upside.
Sproule’s endorsement of the potential at Sagebrush is emphatic: “The Leadville Formation has become a premier helium target in North America, with recent discoveries demonstrating exceptional helium concentrations that far exceed typical commercial thresholds,” the consultant said.
“There is a well-defined, fault-enhanced four-way closure at the Top Leadville horizon covering 588 acres. Seismic data indicate a possible dual target with the overlying Ismay Formation which warrants future evaluation. The Sagebrush-1 Leadville Formation represents a technically credible helium and natural gas resource with sufficient potential to justify further investment in production testing and advanced seismic and petrophysical analysis.”
Mosman now plans the acquisition of high-resolution 3D seismic over an area of approximately 16 square miles. This work is scheduled to commence in October 2025. The survey will provide a much clearer picture of subsurface structures, refine the Sagebrush Leadville closure, and identify additional prospects across both Sagebrush and Coyote Wash.
During the fourth quarter, extended flow testing of Sagebrush-1, with acid stimulation to enhance productivity will also take place.
It should be noted that the Sproule numbers are in fact lower that the internal estimates for Sagebrush released by Mosman in May 2025. The crucial differentiation was Sproule’s evaluation of the porosity at Sagebrush.
Mosman’s internal analysis utilised an 8% porosity value, supported by in-house petrophysics and core data from analogue Leadville wells. Sproule ERCE applied a more conservative 4.6% “most likely” porosity, which has the effect of reducing calculated volumes. Mosman believes this approach understates the contribution from dolomite intervals, vugs and fractures observed in other producing Leadville reservoirs.
Accordingly, Mosman remains confident that real reservoir performance will prove stronger. The company therefore regards the Sproule 2U case of 134 MMscf helium as a baseline from which to build and sees material potential to achieve or exceed these figures as production testing and 3D seismic data are integrated.
“This independent validation by Sproule ERCE is a very significant milestone for Mosman,” said Howard McLaughlin, Mosman’s interim chief executive.
“Sagebrush is now confirmed as both technically credible and commercially attractive. While Sproule has applied conservative assumptions, we believe real reservoir performance will exceed the 2U outcome, consistent with producing Leadville reservoirs. With 3D seismic set to begin, and extended flow testing later this year, Mosman is building strong momentum toward unlocking Sagebrush as a flagship development.”
View from Vox
Good to see hard, independently verified numbers firming up for Sagebrush. Sproule’s endorsement of the project’s potential is unequivocal, even if its numbers are on the conservative side. That leaves the onus on Mosman to build on what it’s already accomplished, and prove up the further potential at Sagebrush. The dollar valuations already look wholesome. Additional work could add considerably more value.