In order to gather data to assess sedimentary geothermal feasibility in Nevada and Utah, state oil and gas and geothermal databases were serached for well files and well logs. Well data from the Nevada Bureau of Mines and Geology oil and gas and geothermal databases was mined for the following areas in Nevada: Blackburn oil field, Marys River, North Willow Creek, Tomera Ranch, and Diamond Valley, all in the Elko Basin; Bacon Flat in Railroad Valley; and Steptoe Basin. For Pavant Butte in Utah, the State of Utah Division of Oil and Gas Well File and Well Log Searches were mined for well records in Millard County. Only wells close to Pavant Butte were mined for detailed information, but all Millard County wells are included in the database. Well files were searched for temperature, permeability, pressure information, and formation depth and thickness. Temperature values are uncorrected. Locations for some wells were converted from township and range locations to approximate latitude and longitude using Google Earth and Earth Point grids to locate well pads. If no well pad could be located for a well, the center of the smallest section available (usually partsect) was used as the approximate location.

The objectives of this project were to (1) perform a literature review of sedimentary geothermal resources, (2) identify data sources and develop data-collection methodologies that characterize selected resources, (3) screen sedimentary basins and formations for sedimentary geothermal potential, and (4) evaluate the technical feasibility of one or more selected locations. Numerous publications have characterized geothermal resources within sedimentary basins. A literature search reviewed publications describing resources located in Colorado, Louisiana, Nevada, Texas, Utah, and Wyoming. The most attractive resources have high temperature gradients, low drilling costs, and reservoir permeabilities greater than 10 millidarcies (mD). Prospects in Colorado, Nevada, Texas, and Utah exhibit attractive characteristics and were chosen for further analysis. Sedimentary resources in Nevada and Utah are most attractive, followed by tested resources in Texas and untested resources in Colorado. The identified resources in Wyoming and Louisiana had lower geothermal gradients and were not evaluated. Reservoir modeling and techno-economic analysis were performed at Marys River Basin - North in Nevada. Geothermal energy production at this location is expected to have a levelized cost of energy (LCOE) ranging between 10 and 20 cents/kWh. Additional work may result in lower LCOE estimates at this location and at other attractive prospects in these three regions. Heat flow within three Colorado sedimentary basins reviewed as part of this study was calculated in targeted studies by the Colorado Geologic Survey and Colorado School of Mines. These calculations are based on bottom-hole temperature datasets with significant limitations and some variability but produce values consistently higher than the global continental average of 65 mW/m2 for all three basins. Heat flow in the Raton Basin is the highest; however, permeability measurements from specific sedimentary formations with high heat flow have not been obtained. Promising formations for sedimentary geothermal systems were found in all three regions studied - Nevada-Utah, Colorado, and Texas.

The objectives of this project were to (1) perform a literature review of sedimentary geothermal resources, (2) identify data sources and develop data-collection methodologies that characterize selected resources, (3) screen sedimentary basins and formations for sedimentary geothermal potential, and (4) evaluate the technical feasibility of one or more selected locations. Numerous publications have characterized geothermal resources within sedimentary basins. A literature search reviewed publications describing resources located in Colorado, Louisiana, Nevada, Texas, Utah, and Wyoming. The most attractive resources have high temperature gradients, low drilling costs, and reservoir permeabilities greater than 10 millidarcies (mD). Prospects in Colorado, Nevada, Texas, and Utah exhibit attractive characteristics and were chosen for further analysis. Sedimentary resources in Nevada and Utah are most attractive, followed by tested resources in Texas and untested resources in Colorado. The identified resources in Wyoming and Louisiana had lower geothermal gradients and were not evaluated. Reservoir modeling and techno-economic analysis were performed at Marys River Basin - North in Nevada. Geothermal energy production at this location is expected to have a levelized cost of energy (LCOE) ranging between 10 and 20 cents/kWh. Additional work may result in lower LCOE estimates at this location and at other attractive prospects in these three regions. Heat flow within three Colorado sedimentary basins reviewed as part of this study was calculated in targeted studies by the Colorado Geologic Survey and Colorado School of Mines. These calculations are based on bottom-hole temperature datasets with significant limitations and some variability but produce values consistently higher than the global continental average of 65 mW/m2 for all three basins. Heat flow in the Raton Basin is the highest; however, permeability measurements from specific sedimentary formations with high heat flow have not been obtained. Promising formations for sedimentary geothermal systems were found in all three regions studied - Nevada-Utah, Colorado, and Texas.

Well data were mined from Geothermal Prospector (GTP), Southern Methodist University (SMU), the Colorado Oil and Gas Conservation Commission (COGCC), and the Colorado Geological Survey (CGS). The well data gathered was then used to assess sedimentary geothermal feasibility in the Denver Basin, the Piceance Basin, and the Raton Basin.

Well data were mined from Geothermal Prospector (GTP), Southern Methodist University (SMU), the Colorado Oil and Gas Conservation Commission (COGCC), and the Colorado Geological Survey (CGS). The well data gathered was then used to assess sedimentary geothermal feasibility in the Denver Basin, the Piceance Basin, and the Raton Basin.

This report describes the geothermal resource at McGee Mountain, including: 1. Local geology 2. Thermal features 3. Known boreholes and temperature gradients 4. Geophysical surveys 5. Fluid geochemistry and geothermometry 6. Estimate of the heat-in-place Description of the heat-in-place estimate: The magnitude of the geothermal resource at McGee Mountain (Painted Hills) has been estimated using a Monte Carlo method applied to estimating heat-in-place. The method relies (along with certain other parameters) on estimates of the area, thickness and average temperature of the resource, but among these, only area has some constraint at this time. Therefore, the estimates used for thickness and temperature have been based on the characteristics of other geothermal resources in Nevada. Results yield a 90%-probable ("P90") thermal energy-in-place estimate of 87,300 MWth-years (that is, 90% of estimates are higher). We consider this to be a minimum likely value. At 50% probability ("P50") the estimate is 134,000 MWth-years. The recoverable portion of the preceding estimate of energy-in-place has also been estimated and converted into electrical energy, using values of recovery factor, rejection temperature, utilization factor, plant capacity factor and power plant life that are provided. The minimum (90% probable) estimate for generation potential is about 25 MWe for 30 years (or a total of 750 MWe-years) and at 50% probability the estimate is 52 MWe for 30 years (or a total of 1,560 MWe-years). These estimates are somewhat larger than a public-domain McGee resource estimate made by GeothermEx in 2004, because a 2-m deep temperature survey by Caldera has established continuance of the thermal anomaly about a half mile further north than previously documented. This resource estimate was made without reference to the Caldera property (project area) boundary, but it is likely that the entire magnitude of estimated resource lies within it. The estimate should be regarded with caution because there needs to be subsequent proof of area, thickness, temperature and commercial permeability by means of deep drilling and testing. No heat-in-place estimate of this type should ever be used to determine the final, installed size of a well field and power plant.

This report describes the geothermal resource at McGee Mountain, including: 1. Local geology 2. Thermal features 3. Known boreholes and temperature gradients 4. Geophysical surveys 5. Fluid geochemistry and geothermometry 6. Estimate of the heat-in-place Description of the heat-in-place estimate: The magnitude of the geothermal resource at McGee Mountain (Painted Hills) has been estimated using a Monte Carlo method applied to estimating heat-in-place. The method relies (along with certain other parameters) on estimates of the area, thickness and average temperature of the resource, but among these, only area has some constraint at this time. Therefore, the estimates used for thickness and temperature have been based on the characteristics of other geothermal resources in Nevada. Results yield a 90%-probable ("P90") thermal energy-in-place estimate of 87,300 MWth-years (that is, 90% of estimates are higher). We consider this to be a minimum likely value. At 50% probability ("P50") the estimate is 134,000 MWth-years. The recoverable portion of the preceding estimate of energy-in-place has also been estimated and converted into electrical energy, using values of recovery factor, rejection temperature, utilization factor, plant capacity factor and power plant life that are provided. The minimum (90% probable) estimate for generation potential is about 25 MWe for 30 years (or a total of 750 MWe-years) and at 50% probability the estimate is 52 MWe for 30 years (or a total of 1,560 MWe-years). These estimates are somewhat larger than a public-domain McGee resource estimate made by GeothermEx in 2004, because a 2-m deep temperature survey by Caldera has established continuance of the thermal anomaly about a half mile further north than previously documented. This resource estimate was made without reference to the Caldera property (project area) boundary, but it is likely that the entire magnitude of estimated resource lies within it. The estimate should be regarded with caution because there needs to be subsequent proof of area, thickness, temperature and commercial permeability by means of deep drilling and testing. No heat-in-place estimate of this type should ever be used to determine the final, installed size of a well field and power plant.

Files contain a summary of the production and injection data submitted by the geothermal operators to the Nevada Bureau of Mines and Geology over the period from 1985 thru 2009

Files contain a summary of the production and injection data submitted by the geothermal operators to the Nevada Bureau of Mines and Geology over the period from 1985 thru 2009

The McGee Mountain geothermal area was selected to test early-stage shallow temperature survey techniques and drill two slim holes to test the resource. Geothermal Technical Partners, Inc. was able to complete only a small portion of the project before lack of funding prevented further exploration work. This work included a shallow (2-meter) temperature survey, a Geoprobe survey, a close-spaced gravity survey, and several reports on geologic and transmission viability. The 18-page report includes a description of the geothermal geology of the area, geochemistry and geothermometry of nearby springs and wells, and findings from the shallow temperature survey, Geoprobe survey, close-spaced gravity survey, heat-in-place estimate, transmission viability, and an archeological survey. The report makes the following conclusions: Both the shallow 2-meter and the Geoprobe surveys are cost-effective methods to detect subsurface thermal anomalies in early-stage exploration, prior to more expensive temperature gradient drilling. The major advantages of the 2-meter survey are its extreme portability (no roads needed), cost per site measurement, and low environmental impact. The 2-meter survey's disadvantages are its inability to penetrate hard substrates and the noise effects due to solar heating of the ground. The Geoprobe's advantages are its ability to collect temperature and uncontaminated water samples, greater depth of penetration (to 60m), relatively low cost, and low environmental impact. The Geoprobe's disadvantages are its inability to go off-road or to penetrate hard substrates. Costs to perform both types of surveys are low, together less than the cost of one conventional temperature gradient well. Given the potential increase in data that these surveys can provide, this is extreme value for the exploration dollar.