Drilling Augustine '25
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GeoAlaska gains entire southern half island, MT survey planned for summer
Kay Cashman Petroleum News
On April 16, GeoAlaska told Petroleum News that effective April 1, the Alaska Department of Natural Resources granted GeoAlaska a geothermal prospecting permit (ADL 394374) covering 7,299 acres on Augustine Island. This acreage expands GeoAlaska's existing geothermal footprint at Augustine Island by 240%, encompassing the entire southern half of the island.
The company already had (ADL 394080), which involved 3,031 acres. The two permits total 10,830 acres,
Based on the expanded acreage and the recommendations contained in an independent geothermal reservoir engineering study commissioned during 2023, GeoAlaska and its partner are commissioning a new magnetotelluric (MT) survey covering the southern half of Augustine Island to be completed during June and July.
GeoAlaska is a geothermal energy company based in Anchorage. The company was founded in May 2020 by Paul L. Craig with the goal of proving sustainable, affordable, carbon-free, baseload geothermal power to the benefit of Alaska and its citizens.
GeoAlaska owns and operates geothermal prospecting permits and leases at Mount Spurr and Augustine Island.
GeoAlaska is partnered with Ignis Energy Inc., a sister company to Geolog. Ignis is involved with geothermal energy projects internationally, while Geolog is well known to the energy industry in Alaska as a premier surface logging company over the past 25 years.
First well 2025 The first geothermal well at Augustine Island is anticipated to be drilled in 2025. Follow-along production and injection wells will be planned, permitted, and drilled on the heels of that first well in 2025.
During 2023, GeoAlaska collected audio-magnetotelluric (AMT) and gravity data at Augustine Island to evaluate ADL 394080. These data were subsequently analyzed by JRG Energy Consultants, an internationally respected geothermal engineering company headquartered in New Zealand.
Using the AMT data, JRG's team identified what is believed to be the apex of a hydrothermal resource; an area within ADL 394080 that Craig has described as 'the sweet spot" -- GeoAlaska's initial lead.
JRG advised GeoAlaska that the AMT signal did not penetrate deeply enough to define the boundaries of the initial lead, including its depth and areal extent. Consequently, JRG was not able to complete further modeling or volumetric analysis.
The potential hydrothermal volume along with other factors such as temperature and flow rate, are required to calculate the amount of baseload geothermal power that a geothermal resource can support on a sustainable basis.
In response to JRG's recommendation to collect MT data that will accurately measure the depth and areal extent of the hydrothermal resource, and due to the 240% increase in acreage under which one or more additional leads may be identified, GeoAlaska and Ignis have decided that the prudent path forward is to collect additional MT data at Augustine Island during 2024 covering both geothermal prospecting permits.
The 2024 MT survey will be designed to measure resistivity at significantly greater depths than the 2023 AMT survey.
According to Craig, 'from a de-risking perspective, collecting the MT data across all of the acreage will result in GeoAlaska having more than a 10-fold increase in useful geophysical data regarding geothermal potential underlying Augustine Island."
Several of the MT readings collected in 2024 will be concentrated around the identified initial lead, while others will be distributed across the entire southern half of the Island to assess prospectivity at depth throughout the newly acquired acreage.
GeoAlaska is also proposing to collect a circle of MT data around the volcanic cone at Augustine in order to infer the location, depth and conformation of the shallow magma chamber(s) estimated by the USGS to be about 4 kilometers below sea level.
Similar to O&G de-risking Craig describes the current situation at Augustine Island as being similar to de-risking an oil or gas prospect identified using 2D seismic data. In Craig's words, 'The 2023 AMT data identified an initial lead. However, the resolution of the AMT data at depth is akin to 2D seismic data in the oil patch, when what you really need is high resolution 3D.
'GeoAlaska and Ignis have decided that it makes sense to collect high resolution MT data over the prospect -- not unlike completing a 3D seismic survey -- to further de-risk drilling and turn the sweet spot' at Augustine into a de-risked prospect."
Craig added, "The incremental cost of collecting MT data at Augustine during 2024 is money well spent. Measuring MT signal at sufficient depth over a larger area will increase our subsurface knowledge at Augustine by more than 10X. If we were to drill immediately, based on the 2023 AMT results, we would be poking and hoping' with the drill bit. Once we have collected the MT data, we will perform further modeling and volumetric analyses, to identify the optimal drilling location for our first exploratory well."
GeoAlaska and Ignis look forward to ongoing collaboration at Augustine, Mount Spurr and beyond, with the hope of meeting a portion of Alaska's current and future baseload energy needs -- sourced from clean, sustainable and affordable geothermal power.
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