Blue Mountain Geothermal Area
Geothermal Area Profile
|Exploration Region:||Northwest Basin and Range Geothermal Region|
|GEA Development Phase:||Operational"Operational" is not in the list of possible values (Phase I - Resource Procurement and Identification, Phase II - Resource Exploration and Confirmation, Phase III - Permitting and Initial Development, Phase IV - Resource Production and Power Plant Construction) for this property.|
|Mean Reservoir Temp:||197°C470.15 K
|Estimated Reservoir Volume:||5.5 km³5,500,000,000 m³
|Mean Capacity:||49.5 MW49,500 kW
|USGS Mean Reservoir Temp:||205°C478.15 K
|USGS Estimated Reservoir Volume:||3 km³|||
|USGS Mean Capacity:||62 MW|||
The Blue Mountain Geothermal Area is located on the western flank of Blue Mountain at an elevation of around 1350 m. The geothermal area is about 35 km west of the town Winnemucca in northern Nevada. The climate is semi-arid and the area receives an annual precipitation of approximately 15-18 cm. The average temperature is around 10.5°C, and local vegetation consists of desert plants and shrubs. One geothermal power plant, the Faulkner I Energy Generation Facility (Figure 1), has been developed in the area. It is a binary power plant that was commissioned in 2009, with a configuration of six turbines rated at 8.25 MW each. The power plant has a gross production of 49.5 MW and a net production of 39.5 MW.
History and Infrastructure
Operating Power Plants: 1
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Developing Power Projects: 0
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Power Production Profile
|Gross Production Capacity:||49.5 MW49,500 kW
|Net Production Capacity:|
|Power Purchasers :|
The geothermal area is a blind system with no visible hydrothermal features, so the geothermal resource was unknown until hot water was discovered in drill holes made for mineral exploration in the early 1990s. Geothermal drilling at Blue Mountain began in 2002 with the drilling of a slim hole observation well named Deep Blue No. 1 (DB1). A second slim hole (DB2) was drilled and completed in 2004. Information from these two wells showed that geothermal energy could be commercially produced at Blue Mountain. Geothermal production and injection wells began to be drilled in 2005, and in 2009 the 49.5-MW Faulkner I Energy Generation Facility was commissioned.
Ormat Nevada (a subsidiary of Ormat Technologies, Inc.) constructed the plant and completed it four months ahead of schedule. The plant was brought online in September of 2009. The project area covers 45 km2 and the plant is now operated by Alternative Earth Resources, Inc., formerly known as Nevada Geothermal Power, Inc. (NGP). In March of 2013, NGP transferred ownership to Alternative Earth Resources, Inc. NGP constructed the transmission line, which consists of a 20 mile long, 120kV overhead line, with a maximum capacity of 75 MW that connects to the electric grid just north of Mill City, Nevada.
Blue Mountain Timeline
1984-1990: Precious metal exploration by Nassau Ltd. begins at Blue Mountain.
early 1990s: Mineral exploration drilling encounters a hot water resource at Blue Mountain.
1993-1994: Noramex Corporation obtains geothermal leases and begins exploring for geothermal resources in the Blue Mountain area.
2000: The DOE awards Noramex Corporation funding through the Geothermal Resource Exploration and Definition cost share program to continue exploration drilling at Blue Mountain.
2002: Geothermal exploration drilling begins at Blue Mountain with the drilling of the Deep Blue No. 1 slim hole.
2004: A second slim hole (Deep Blue No. 2) is drilled to further test the geothermal resource.
2005: Injection and production well drilling begins at Blue Mountain.
2007: Internal Noramex and NGP reports by Adam Szybinski provide new insights on the structural character of the reservoir rock (Triassic metasedimentary rock).
2007: Report by Optim provides new seismic reflection data from Blue Mountain.
2007: Nevada Geothermal Power Co. signs construction contract for Blue Mountain Faulkner I binary power plant, with an estimated 49.5 MW gross yield. Approval received for construction of a 20 mile long 120 kV overhead transmission line.
2008: Melosh et al. present the results of new drilling successes and geochemical analysis contributing to the conceptual model of the Blue Mountain hydrothermal system.
2008: Faulds et al. develop a new conceptual structural model for the Blue Mountain geothermal system integrating data from previous studies.
2009: The six turbine Faulkner I binary power plant is commissioned at Blue Mountain with a net production of 39.5 MW. Facility construction by Ormat Nevada is completed and the plant is brought online in September 2009.
2010: Casteel et al. present an updated conceptual model of the Blue Mountain hydrothermal system at the World Geothermal Congress (WGC) with respect to new and existing geochemical data.
2010: Melosh et al. present new seismic reflection data at WGC and interpret the likely attitudes of faults controlling fluid flow within the Blue Mountain hydrothermal system.
2013: Ownership of the Faulkner I power plant is transferred to the current operator, Alternative Earth Resources, Inc.
Regulatory and Environmental Issues
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In a statement made in May 2012 by Brian D. Fairbank, President & CEO of Nevada Geothermal Power, Inc., future development plans include drilling two new injection wells and one new production well, thus increasing power generation capacity to 52 MW (gross) and 41 MW (net). A timeline of these developments is not provided, and since the ownership of the power plant has changed since this statement, it is unknown if these plans will be carried out.
First Discovery Well
|Well Name:||DEEP BLUE No.1 (DB1)|
|Initial Flow Rate:||2 kg/s120 kg/min
|Flow Test Comment:|
|Initial Temperature:||145°C418.15 K
Interest in the Blue Mountain Geothermal Area originally began due to gold exploration efforts in the region. A large amount of exploration work for precious metals was done from 1984-1990. The mining company that had a claim on the land at that time was Nassau Ltd., who carried out many surveys while looking for valuable minerals. Nassau Ltd. performed detailed geologic mapping, aeromagnetic and ground magnetic surveys, airborne VLF-EM, IP-electrical resistivity, gravity, seismic reflection, and soil and rock geochemistry. Although these surveys were not intended for geothermal exploration, the aeromagnetic, seismic, and resistivity surveys did provide useful information for the geothermal program. Over 130 exploration holes were drilled by mining companies, many of which encountered hot water. Temperatures of up to 81°C were recorded in some holes, and six of the drill holes produced artesian flows of 1.3-1.9 liters/sec.
In 1993 and 1994 Noramex acquired geothermal leases in the area and began a geothermal exploration program. The company completed detailed geologic mapping and aerial photography. In 1994 a program to drill 13 shallow temperature gradient drill holes, three medium depth holes, and two 914 m-deep slim-holes began. The goal of this exploratory drilling program was to locate and intersect the geothermal reservoir. Between 1996 and 1998 the Energy and Geoscience Institute (EGI) of the University of Utah worked in collaboration and did a Self Potential survey, induced polarization electrical resistivity surveys, and detailed temperature measurements in 11 new mineral exploration drill holes.
In 2000, the U.S. Department of Energy (DOE) awarded Noramex funding for a cost share program called the Geothermal Resource Exploration and Definition (GRED) program. As part of this program two slim geothermal observation holes were drilled, DB1 and DB2. DB1 was completed in 2002 and DB2 was completed in 2004; well logging for pressure, temperature, and gamma was conducted in the wells. Information gained from the two observation wells indicated that a commercial geothermal resource was feasible at Blue Mountain and the following year, the drilling started for full-sized production wells.
Well Field Description
Well Field Information
|Number of Production Wells:||6|||
|Number of Injection Wells:||4|||
|Number of Replacement Wells:|
|Average Temperature of Geofluid:||379 193°C466.15 K
|Sanyal Classification (Wellhead):||Moderate Temperature|||
|Reservoir Temp (Geothermometry):|
|Reservoir Temp (Measured):||250°C523.15 K
|Sanyal Classification (Reservoir):||High Temperature|||
|Depth to Top of Reservoir:||600m0.6 km
|Depth to Bottom of Reservoir:||1070m1.07 km
|Average Depth to Reservoir:||835m0.835 km
Two deep exploration slim wells were drilled in the geothermal field in order to assess the geothermal resource before any full-sized production wells were drilled. The first geothermal observation hole, DB1, was drilled in 2002 by Noramex Corporation. It reached a depth of 672.1 m and a temperature of 144.7°C. DB2, completed in 2004, reached 1128 m depth and a maximum temperature of 167.5°C. The first production well (26A-14) was completed in 2006; it reached a modest depth of 862.5 m and a temperature of 186°C. The well is cased down to 591 m and the bottom of the well is 12 ¼ inches in diameter. This well flows about 500kph at 80psig and can produce about 7 MW.
As of 2010, the geothermal area consisted of ten thermal gradient holes, six observation wells, six production wells, and four injection wells. The production wells drilled early in the project (14-14, 15-14, and 17-14) all have capacities of between 7-7.5 MW. The resource that these wells tap into is an artesian reservoir at an elevation of around 335 m. Geothermometers from these wells predict a reservoir temperature of up to 250°C.
Technical Problems and Solutions
In 2011 the Faulkner 1 Geothermal Plant was adversely affected by lower power production than expected, but the reasons behind the low production were not divulged. The power production forecast was 35 MW (net) rather than the planned 39.5 MW. Also, a decline of 2.5% per year was predicted. Solutions to this problem, if any, are not stated in the report.
Silica concentrations at Blue Mountain are high in the geothermal fluids, which poses a problem. As the fluid cools, silica becomes oversaturated and precipitates out of solution, causing scaling in pipelines. In order to mitigate this issue, chemicals are added that prevent the silica from becoming oversaturated in solution.
Geology of the Area
|Modern Geothermal Features:||Blind Geothermal System|||
|Relict Geothermal Features:||Argillic-Advanced Argillic Alteration, Hydrothermally Altered Rock, Hydrothermally Deposited Rock, Silicification|||
|Volcanic Age:||No Volcanism|
|Host Rock Age:||Triassic|||
|Host Rock Lithology:||Metasedimentary|||
|Cap Rock Age:|
|Cap Rock Lithology:||Hydrothermal alteration layer|||
The Blue Mountain Geothermal Area is in northern Nevada and lies within the Basin and Range Province. It is located along the west flank of Blue Mountain in southern Humboldt County (Figure 2). The Basin and Range consists of widespread extension and crustal thinning. Normal faulting with moderate- to high-angle dips and NNE-trending strikes dominate the region. The majority of fault blocks in the region tilt moderately eastward and are between major west dipping normal faults. Zones of fracturing and faulting in the Basin and Range provide permeable pathways for deep circulation of fluids which can then transfer heat from the deep crust to the surface.
The fault system that runs through the Blue Mountain Geothermal Area is called the Humboldt Structural Zone (HSZ). Blue Mountain is within the Battle Mountain heat flow high zone, a large region of relatively high heat flow in the northern Basin and Range. There are no surface manifestations such as hot springs or fumaroles at Blue Mountain, so the geothermal area is considered a blind system.
Rock structures at the Blue Mountain Geothermal Area generally strike N70°E and dip gently to the northwest. The majority of the structures in the area are Miocene to early Quaternary in age, in addition to some Holocene-age fault scarps. Steeply dipping, Tertiary age, normal faults cut through the meta-sedimentary rocks in the area. Three separate sets of high-angle normal faults have been identified by geologic mapping, aerial photographs, and rock samples from drill sections. The most obvious fault structures form along the southwestern side of Blue Mountain. These faults are noted to truncate diabase dykes. Fault structures along the northwest side of Blue Mountain are likely the control for most of the hydrothermal alterations that are exposed at the surface. The youngest of the three fault sets are high angle, west-dipping normal faults located at the western base of Blue Mountain. Borehole televiewer image logs from two production wells show fracture orientations with dips to the east and west, which strike between NNW-SSE and NNE-SSW. Some of the faults seen on the surface may be related to the observed downhole faults.
The geothermal field occupies the intersection between a regional NNE- to ENE-striking, west-dipping normal-sinistral fault system, which bounds the west flanks of Blue Mountain and the Eugene Mountains, and a more local WNW-striking, SW-dipping normal-dextral fault on the southwest side of Blue Mountain. Fluid flow appears to be controlled by a dilatant fault intersection, which is partly caused by strong basement fabrics orientated with Neogene faults. Quartz veins are common around Blue Mountain and are especially abundant near the major range front fault on the northwest flank of the mountain.
Blue Mountain consists of three Triassic meta-sedimentary stratigraphic units which, when combined, are over 6 km thick. Detailed descriptions of the Triassic metasedimentary host rock at Blue Mountain are available in geologic maps of the area prepared by Szybinski (2007)  and in maps of the Eugene Mountains directly to the south provided by Thole and Prihar (1998). The Blue Mountain Geothermal Area consists of a surface layer of unconsolidated sands, silts, and gravels that form the Quaternary alluvium fill. Beneath the alluvium, there is a mudstone layer, and below that is mainly an argillite formation that is cut by numerous fine- to medium- grained diorite to gabbro dikes. Below about 40 m, the core samples have revealed mainly silicified rocks with abundant pyrite and many clusters of quartz veins cross-cutting the core samples. At least some of the silicification appears to be associated with late Tertiary to Quaternary deposits of hydrothermal minerals. The layer immediately above the reservoir contains mainly argillic-altered rocks that are very high in clay content. The percentage of clay decreases as silicic alterations increase when entering the reservoir. The deep and intermediate core of the reservoir is hosted within silicic, argillic, meta-sedimetary, and intrusive formations. The permeability in the geothermal area does not appear to be directly related to lithology and is mainly controlled by localized faulting.
The geothermal reservoir is hosted within a network of faults and fractures. The bulk flow of hydrothermal fluids circulate along a major NE-trending range front fault. Artesian flow below an elevation of approximately 335 m occurs in the geothermal area (Figure 3). Hydrothermal alterations are predominant along the western slopes of Blue Mountain. Mineral exploration was focused around the area of alteration. The hydrothermal alterations are siliceous in nature and most prominent along intersections of faults and fracture zones. The alterations are late Tertiary to Quaternary in age and consist of quartz veins and stockworks, chalcedonic and reddish-brown opaline silica hot spring deposits, intense silicification, argillic alteration, alunite replacement, quartz-alunite replacement, veining, and the formation of numerous clays.
The heat source for the Blue Mountain Geothermal Reservoir is similar to that of other Basin and Range geothermal areas. Due to the extensional structural setting, the crust is thinning; therefore, deep circulation of fluid within highly fractured rock can occur. A lack of recent volcanism indicates that there is no significant magmatic thermal input in the upper crust. The heat is transferred via faults and fractures from deep rock within the crust. Maximum temperatures observed in the geothermal wells are 188°C at around 610 m.
The Blue Mountain geothermal reservoir is classified as a hot liquid-saturated convective geothermal system. The water circulating throughout the system is neutral-pH with dilute alkali-Cl and low-to-moderate non-condensable gasses. The reservoir fluids are initially unsaturated with respect to silica and calcite. Hydrothermal fluids used for power production become oversaturated in silica when they cool, which causes a potential for scaling in pipelines, but an anti-scaling compound is injected before the fluids reach the heat exchangers, thus preventing silica from precipitating.
Sulfur, barite, cinnabar, and iron oxide minerals are common within the clay alterations that have developed on the west flank of Blue Mountain. Silica levels are high in the hydrothermal alteration areas; silica deposition is so prominent that many veins and fractures have been clogged. Gold mineralization has taken place in the geothermal area; however, it is not in high enough concentrations to make extraction economical.
NEPA-Related Analyses (2)
Below is a list of NEPA-related analyses that have been conducted in the area - and logged on OpenEI. To add an additional NEPA-related analysis, see the NEPA Database.
Exploration Activities (29)
Below is a list of Exploration that have been conducted in the area - and cataloged on OpenEI. Add a new Exploration Activity
- Ruggero Bertani. 2005. World Geothermal Power Generation 2001-2005. Proceedings of World Geothermal Congress; Turkey: World Geothermal Congress.
- Geothermex Inc.. 2004. New Geothermal Site Identification and Qualification. Richmond, CA: California Energy Commission. Report No.: P500-04-051. Contract No.: 500-04-051.
- Benjamin Matek. Geo-energy [Internet]. Geothermal Energy Association. [updated 2015/04/28;cited 2015/04/28]. Available from: http://geo-energy.org/
- U.S. Geological Survey. 2008. Assessment of Moderate- and High-Temperature Geothermal Resources of the United States. USA: U.S. Geological Survey. Report No.: Fact Sheet 2008-3082.
- Fairbank Engineering Ltd (Fairbank Engineering Ltd). 2003. Phase I Report U.S. DOE GRED II Program. Albuquerque, NM: Noramex Corporation. Report No.: DE-FC04-2002AL68297.
- Lisa Shevenell,Richard Zehner. 2011. Status of Nevada Geothermal Resource Development - Spring 2011. Geothermal Resources Council Transactions. .
- Andrew J. Parr,Timothy J. Percival. 1991. Epithermal Gold Mineralization and a Geothermal Resource at Blue Mountain, Humboldt County, Nevada. Geothermal Resources Council Transactions. 15:35-39.
- Brian D. Fairbank, Kim V. Niggemann. 2004. Deep Blue No.1-A Slimhole Geothermal Discovery at Blue Mountain, Humboldt County, Nevada. In: GRC Transactions. GRC Annual Meeting; 2004/08/29; Indian Wells, California. Davis, California: Geothermal Resources Council; p. 333-338
- Niggemann Kim, Fairbank Brian, Petty Susan. 2005. Deep Blue No. 2-A Resource in the Making at Blue Mountain. In: GRC Transactions. GRC Annual Meeting; 2005/09/25; Reno, Nevada. Davis, California: Geothermal Resources Council; p. 289-294
- Nevada Geothermal Power Inc. Completes Transfer of Ownership in the Blue Mountain Geothermal Project to EIG Global Energy Partners [Internet]. 2013. marketwatch.com. MarketWatch. [cited 2013/08/27]. Available from: http://www.marketwatch.com/story/nevada-geothermal-power-inc-completes-transfer-of-ownership-in-the-blue-mountain-geothermal-project-to-eig-global-energy-partners-2013-04-01-14183550
- Adam Szybinski (Conducted for Nevada Geothermal Power, Inc.). 2007. Revised Structural Setting of the Blue Mountain Geothermal Development Project Area, Humboldt County, Nevada. unavailable: unavailable.
- Glenn Melosh, John Casteel, Kim Niggeman, Brian Fairbank. 2008. Step-Out Drilling Results at Blue Mountain, Nevada. In: GRC Transactions. GRC Annual Meeting; 2008/10/05; Reno, Nevada. Davis, California: Geothermal Resources Council; p. 49-52
- James E. Faulds, Glenn Melosh. 2008. A Preliminary Structural Model for the Blue Mountain Geothermal Field, Humboldt County, Nevada. In: GRC Transactions. GRC Annual Meeting; 2008/10/05; Reno, Nevada. Davis, California: Geothermal Resources Council; p. 273-278
- John Casteel, Rogel Trazona, Glenn Melosh, Kim Niggemann, Brian Fairbank. 2010. A Preliminary Conceptual Model for the Blue Mountain Geothermal System, Humboldt County, Nevada. In: Proceedings World Geothermal Congress. World Geothermal Congress; 2010/04/25; Bali, Indonesia. Bali, Indonesia: International Geothermal Association; p. 6
- Glenn Melosh, William Cumming, John Casteel, Kim Niggemann, Brian Fairbank. 2010. Seismic Reflection Data and Conceptual Models for Geothermal Development in Nevada. In: Proceedings World Geothermal Congress 2010. Proceedings World Geothermal Congress 2010; 2010/04/25; Bali, Indonesia. Bali, Indonesia: International Geothermal Association; p. 6
- Brian D. Fairbank. 16/05/2012. STATEMENT OF BRIAN D. FAIRBANK Nevada Geothermal Power Inc.’s Blue Mountain Geothermal Power Facility. Personal Communication sent to unknown.
- Glenn Melosh, Brian Fairbank, Kim Niggeman, Nevada Geothermal Power. 2008. Geothermal Drilling Success at Blue Mountain, Nevada. In: Proceedings 33rd Workshop on Geothermal Reservoir Engineering. Proceedings 33rd Workshop on Geothermal Reservoir Engineering; 2008/01/28; Stanford University. Stanford, California: Stanford University; p. 28–30
- James E. Faulds,Nicholas H. Hinz,Mark F. Coolbaugh,Patricia H. Cashman,Christopher Kratt,Gregory Dering,Joel Edwards,Brett Mayhew,Holly McLachlan. 2011. Assessment of Favorable Structural Settings of Geothermal Systems in the Great Basin, Western USA. In: Transactions. GRC Anual Meeting; 2011/10/23; San Diego, CA. Davis, CA: Geothermal Resources Council; p. 777–783
- D. A. Ponce, C. Bouligand, J. Casteel, J. M. Glen, J. T. Watt. 2010. Geophysical Setting of the Blue Mountain Geothermal Area, North-Central Nevada and Its Relationship to a Crustal-Scale Fracture Associated with the Inception of the Yellowstone Hotspot. AGU Fall Meeting Abstracts. 34(N/A):881-886.
- Ronald H. Thole, Douglas W. Prihar. Geologic Map of the Eugene Mountains, Northwestern Nevada. [Map]. Reno, Nevada. Nevada Bureau of Mines and Geology. 1998. Scale 1:24,000. Available from: http://searchworks.stanford.edu/view/4266444.
List of existing Geothermal Resource Areas.
Some of the content on this page was part of a case study conducted by: NREL Interns