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DNR inviting geothermal exploration
Agency seeking applicants interested in exploration on 12 land tracts near Mount Spurr on the west side of the Cook Inlet
Alan Bailey Petroleum News
Following a request for the nomination of land for interest in geothermal exploration, the Alaska Department of Natural Resources’ Division of Oil and Gas is calling for applications for exploration near Mount Spurr volcano on the west side of Cook Inlet. The division is proposing to allow exploration on 12 tracts covering 28,800 acres of state land on the flank of the mountain, about 40 miles west of the village of Tyonek.
Applications must be received by the division by 5 p.m. on March 21.
The concept would presumably involve finding sufficient subsurface heat for the generation of electricity.
Enticing target Land near Mount Spurr is an enticing target for geothermal exploration, given the natural heat coming from activity within the volcano and the relative proximity to the Alaska Railbelt electricity grid - the Beluga power station at one extremity of the grid is some 40 miles from the area of exploration interest. A geophysical survey conducted in the 1980s pointed to the possible existence of a layer of warm or hot brine 2,000 feet below a plateau at the entrance to the pass on the south flank of the mountain. There were also geochemical indications of geothermal water in the area.
And there has been previous geothermal interest in the mountain.
Ormat exploration In 2008 geothermal company Ormat Technologies bought 15 leases on the mountain’s flanks. In 2009 the company began evaluating the leases using various types of aerial survey, together with gravity and electromagnetic measurements. That led to the drilling of two core holes to depths of 1,000 feet in 2010. The following year the company brought in a drilling rig to drill to a depth of 4,000 feet.
According to a report presented to the Alaska Senate Resources Committee the deeper well encountered a rock that does not hold heat particularly effectively. The well encountered no hot water and subsurface temperatures no higher than 140 F. There may also have been some mixing of geothermal fluid with cold glacial water from the surface, the company said.
Ormat planned further field work and drilling, perhaps testing the subsurface closer to the volcano’s crater. However, in February 2015 the company announced that it was discontinuing its Mount Spurr venture, writing off the $7.3 million it had invested in the project.
Given the sparsity of the coring and drilling, it seems premature to write off the geothermal potential of a location where there clearly must be subsurface heat. Mount Spurr may yet prove a viable source of energy for the Railbelt.
Mount Augustine On this occasion the state is not offering geothermal exploration opportunities on the flanks of Mount Augustine, another volcano on the west side of the Cook Inlet. Presumably no one has nominated this area for potential exploration. Mount Augustine, while having obvious geothermal potential, suffers from the disadvantage of being situated a long way from the nearest electricity infrastructure - Beluga is 150 miles to the northwest and Nikiski is 112 miles away, on the east side of the inlet.
- ALAN BAILEY
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