Production test activities at Vintage Energy’s (ASX: VEN) 50%-owned Nangwarry-1 well in the onshore Otway Basin has generated strong carbon dioxide gas flows from the lower section of the Top Pretty Hill Formation.
Log data had previously indicated the flow would be at a lower rate within this lower section of the formation compared to the upper section.
However, to-date the flow rate has “easily exceeded” Vintage’s expectations at an estimated 12-14 million standard cubic feet per day (MMscfd).
Vintage managing director Neil Gibbins said the company was “extremely pleased” the first perforation zone in the deepest part of the Top Pretty Hill Formation had delivered an “excellent result” with strong carbon dioxide gas flows.
“The most pleasing part of this result is that the gas flow came from the lower section of the interpreted gas column,” Mr Gibbins added.
Production testing at Nangwarry-1 started last Friday 19 March and initially targeted the Mid-Pretty Hill Zone.
Perforation of this zone was to expectation and isolated, with testing focusing on the main target the Top Pretty Hill Formation.
As testing advances at the well, Vintage will continue evaluating the uppermost part of the Top Pretty Hill Formation over the coming days.
Once this uppermost section has been perforated, Vintage says it will extend production testing to quantify the well’s flow rate and analyse the pressure data to gauge connected volumes. This work will be completed in the “coming weeks”.
At completion of production testing, Vintage expects to have a stabilised flow rate and volumetric estimate of the recoverable carbon dioxide.
Gross recoverable estimates for Nangwarry-1 comprise 7.8 billion cubic feet of carbon dioxide (low), 25.1Bcf of carbon dioxide (best), and 82.1Bcf of carbon dioxide (high).
Food grade carbon dioxide
Vintage says the current testing at Nangwarry-1 is a “key milestone” as the company advances its path towards producing its first food grade carbon dioxide.
The production test will confirm volumes of saleable carbon dioxide and pave the way for Vintage and its joint venture partner Otway Energy to consider debt funding options to bring the well online.
According to Vintage, a stable source of food-grade carbon dioxide is in high demand, with a nearby well Caroline-1 ceasing production after 50 years.
Food grade carbon dioxide is used in refrigeration/dry ice for storage of products including vaccines. It is also used in carbonation of soft drinks, beer, firefighting, medical devices and winemaking.