Omai resource update in Guyana: mine planning and PEA takeaways for engineers
Reviewed by Joe Ashwell
First reported on MINING.com
30 Second Briefing
Omai Gold Mines has increased total resources at its past-producing Omai project in central Guyana to 8 million oz., up from 6.5 million oz., with indicated resources now 38.1 million tonnes at 2.04 g/t and inferred 106.6 million tonnes at 1.59 g/t, after 18,000 metres of drilling and updated modelling. The Wenot open-pit deposit now holds about 1.45 million oz. indicated at 1.59 g/t and 3.9 million oz. inferred at 1.33 g/t, while the Gilt Creek underground resource has grown to roughly 2.5 million oz. at 3.26 g/t. A new PEA due within three months is expected to evaluate a combined open-pit/underground operation targeting 250,000–300,000 oz. per year with a larger mill, ahead of a planned prefeasibility study and 50,000-metre drill campaign.
Technical Brief
- August 2025 resource stood at 20.7 Mt indicated at 1.46 g/t and 83 Mt inferred at 1.7 g/t.
- Contained indicated ounces have risen from 970,000 oz. to 2.5 million oz. through infill and re‑interpretation.
- Analysts attribute conversion mainly to high‑grade dyke corridor material upgraded from inferred to indicated.
- Gilt Creek underground resource increased from ~1.8 million oz. to ~2.5 million oz. while maintaining ~3.26 g/t grade.
- About 18,000 m of drilling completed since the last estimate, with a 50,000 m campaign now underway.
- Previous 2024 plan envisaged open‑pit‑only production of ~142,000 oz. per year over 13 years.
- New PEA is expected to supersede the 2024 open‑pit‑only case with a combined pit/underground scenario.
- Analysts flag existing infrastructure, permitting position and enlarged scale as making Omai a potential senior/intermediate M&A target.
Our Take
With Omai Gold Mines already featuring in our coverage for high‑grade hits at Wenot (hole 25ODD‑142 returning 14.7 metres at 11.07 g/t), the move to 8 million oz. in resources suggests the project is transitioning from a brownfields curiosity to a scale comparable with the more advanced Latin American gold projects we track in the 1202 Mining stories corpus.
The step‑change in underground ounces at Gilt Creek, combined with a prior 13‑year open‑pit‑only mine life, implies that the forthcoming PEA in Guyana is likely to test a hybrid pit‑plus‑underground scenario, which in our database typically improves NPV but tightens early‑year capital and geotechnical requirements around the historical pit shell.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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