A hybrid geothermal energy conversion technology: Auxiliary heating of geothermally preheated water or CO2 - a potential solution for low-temperature resources

Science.gov (United States)

Saar, Martin; Garapati, Nagasree; Adams, Benjamin; Randolph, Jimmy; Kuehn, Thomas

2016-04-01

Safe, sustainable, and economic development of deep geothermal resources, particularly in less favourable regions, often requires employment of unconventional geothermal energy extraction and utilization methods. Often "unconventional geothermal methods" is synonymously and solely used as meaning enhanced geothermal systems, where the permeability of hot, dry rock with naturally low permeability at greater depths (4-6 km), is enhanced. Here we present an alternative unconventional geothermal energy utilization approach that uses low-temperature regions that are shallower, thereby drastically reducing drilling costs. While not a pure geothermal energy system, this hybrid approach may enable utilization of geothermal energy in many regions worldwide that can otherwise not be used for geothermal electricity generation, thereby increasing the global geothermal resource base. Moreover, in some realizations of this hybrid approach that generate carbon dioxide (CO2), the technology may be combined with carbon dioxide capture and storage (CCS) and CO2-based geothermal energy utilization, resulting in a high-efficiency (hybrid) geothermal power plant with a negative carbon footprint. Typically, low- to moderate-temperature geothermal resources are more effectively used for direct heat energy applications. However, due to high thermal losses during transport, direct use requires that the heat resource is located near the user. Alternatively, we show here that if such a low-temperature geothermal resource is combined with an additional or secondary energy resource, the power production is increased compared to the sum from two separate (geothermal and secondary fuel) power plants (DiPippo et al. 1978) and the thermal losses are minimized because the thermal energy is utilized where it is produced. Since Adams et al. (2015) found that using CO2 as a subsurface working fluid produces more net power than brine at low- to moderate-temperature geothermal resource conditions, we

Data Acquisition for Low-Temperature Geothermal Well Tests and Long-Term Monitoring

Energy Technology Data Exchange (ETDEWEB)

Lienau, P J

1992-03-01

Groundwater monitoring is an essential part of the development of a low-temperature geothermal field for production and injection wells. State water resource and environmental departments are requiring both geothermal well testing and long-term monitoring as a part of the permitting process for geothermal developments. This report covers water-level measurement methods, instruments used for well testing, geochemical sampling, examples of data acquisition and regulatory mandates on groundwater monitoring.

Data acquisition for low-temperature geothermal well tests and long-term monitoring

Energy Technology Data Exchange (ETDEWEB)

Lienau, P.J.

1992-09-01

Groundwater monitoring is an essential part of the development of a low-temperature geothermal field for production and injection wells. State water resource and environmental departments are requiring both geothermal well testing and long-term monitoring as a part of the permitting process for geothermal developments. This report covers water-level measurement methods, instruments used for well testing, geochemical sampling, examples of data acquisition and regulatory mandates on groundwater monitoring.

Understanding the circulation of geothermal waters in the Tibetan Plateau using oxygen and hydrogen stable isotopes

International Nuclear Information System (INIS)

Tan, Hongbing; Zhang, Yanfei; Zhang, Wenjie; Kong, Na; Zhang, Qing; Huang, Jingzhong

2014-01-01

Highlights: • Unique geothermal resources in Tibetan Plateau were discussed. • Isotopes were used to trace circulation of geothermal water. • Magmatic water mixing dominates geothermal water evolution. - Abstract: With the uplift of the Tibetan Plateau, many of the world’s rarest and most unique geothermal fields have been developed. This study aims to systematically analyze the characteristics of the hydrogen and oxygen isotopic data of geothermal, river, and lake waters to understand the circulation of groundwater and to uncover the mechanism of geothermal formation in the Tibetan Plateau. Field observations and isotopic data show that geothermal water has higher temperatures and hydraulic pressures, as well as more depleted D and 18 O isotopic compositions than river and lake waters. Thus, neither lakes nor those larger river waters are the recharge source of geothermal water. Snow-melt water in high mountains can vertically infiltrate and deeply circulate along some stretching tensile active tectonic belts or sutures and recharge geothermal water. After deep circulation, cold surface water evolves into high-temperature thermal water and is then discharged as springs at the surface again in a low area, under high water-head difference and cold–hot water density difference. Therefore, the large-scale, high-temperature, high-hydraulic-pressure geothermal systems in the Tibetan Plateau are developed and maintained by rapid groundwater circulation and the heat source of upwelled residual magmatic water. Inevitably, the amount of geothermal water will increase if global warming accelerates the melting of glaciers in high mountains

Transported Low-Temperature Geothermal Energy for Thermal End Uses Final Report

Energy Technology Data Exchange (ETDEWEB)

Yang, Zhiyao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Xiaobing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gluesenkamp, Kyle R [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mehdizadeh Momen, Ayyoub [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Li, Jan-Mou [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-10-01

The use of geothermal energy is an emerging area for improving the nation’s energy resiliency. Conventionally, geothermal energy applications have focused on power generation using high temperature hydrothermal resources or enhanced geothermal systems. However, many low temperature (below 150°C/300°F) geothermal resources are also available but have not been fully utilized. For example, it is estimated that 25 billion barrels of geothermal fluid (mostly water and some dissolved solids) at 176°F to 302°F (80°C to 150°C) is coproduced annually at oil and gas wells in the United States (DOE 2015). The heat contained in coproduced geothermal fluid (also referred as “coproduced water”) is typically wasted because the fluid is reinjected back into the ground without extracting the heat.

Utilization of low temperature geothermal water in traditional and advanced agricultural applications

International Nuclear Information System (INIS)

Rossi, L.; Pacciaroni, F.

1992-01-01

The locations of large amounts of low temperature geothermal sources (30 to 80 degrees C) have been identified in Italy and in many European countries; one of the most interesting utilization of these sources is greenhouse heating. Surplus investment in comparison with conventional heating systems is justified only by the application of low cost technologies for well completion, heating distribution and waste heat treatment. In the last few years, many efforts have been made in the development of these technologies and selection of more profitable crops. Since 1984, ENEA (Italian Agency for Energy, New Technologies and the Environment) has carried out experimental work in two geothermal stations located in Canino (VT) and in Gorgo di Latisana (UD). In these plants, a number of greenhouses enveloped with plastic film are provided with different heating systems; the combination of soil and forced air heating is preferred. Plastic pipes, buried in the soil, are used as soil heating for horticulture and fruit production. For plot plant cultivation, soil heating is obtained by plastic pipes half-buried in a concrete floor. Asparagus cultivation is carried out with buried pipes. No additional heating with conventional fuel is provided in any greenhouse. During these years, ENEA has developed heating and water distribution technologies: current industrial components are generally utilized. Moreover, ENEA has recently completed an advanced automatic control system able to control geothermal greenhouses, manage water distribution, save energy and optimize environmental conditions

Utilization of low temperature geothermal water in traditional and advanced agricultural applications

Energy Technology Data Exchange (ETDEWEB)

Rossi, L.; Pacciaroni, F.

1992-12-31

The locations of large amounts of low temperature geothermal sources (30 to 80 degrees C) have been identified in Italy and in many European countries; one of the most interesting utilization of these sources is greenhouse heating. Surplus investment in comparison with conventional heating systems is justified only by the application of low cost technologies for well completion, heating distribution and waste heat treatment. In the last few years, many efforts have been made in the development of these technologies and selection of more profitable crops. Since 1984, ENEA (Italian Agency for Energy, New Technologies and the Environment) has carried out experimental work in two geothermal stations located in Canino (VT) and in Gorgo di Latisana (UD). In these plants, a number of greenhouses enveloped with plastic film are provided with different heating systems; the combination of soil and forced air heating is preferred. Plastic pipes, buried in the soil, are used as soil heating for horticulture and fruit production. For plot plant cultivation, soil heating is obtained by plastic pipes half-buried in a concrete floor. Asparagus cultivation is carried out with buried pipes. No additional heating with conventional fuel is provided in any greenhouse. During these years, ENEA has developed heating and water distribution technologies: current industrial components are generally utilized. Moreover, ENEA has recently completed an advanced automatic control system able to control geothermal greenhouses, manage water distribution, save energy and optimize environmental conditions.

The Use of Geothermal Waters in Podhale in Terms of Tourism and Industrial Applications

Directory of Open Access Journals (Sweden)

Piotr Michał Bugajski

2017-11-01

Full Text Available In recent years, there has been observed an increased interest of various industrial and economy branches in geothermal waters. In Poland, one of the more famous geothermal systems is the Podhale Basin, which forms an important reservoir of geothermal waters with relatively low mineralization and high temperatures. More and more often geothermal water is used not only for balneological or recreational purposes, but also as a heat source for heating. New areas of application of geothermal waters are also appearing, eg. use of cooled geothermal water as a raw material to produce fresh water. Another example of the application of geothermal waters is the cosmetic industry. For instance, a cream based on geothermal water from Podhale was introduced to the cosmetics market in 2013. This paper presents the possibilities of using the geothermal waters of Podhale, with particular emphasis on geothermal waters from Banska PGP-1, Banska IG-1 and Banska PGP-3 boreholes.

Application of subsurface temperature measurements in geothermal prospecting in Iceland

Science.gov (United States)

Flóvenz, Ólafur G.

1985-12-01

In geothermal areas in Iceland aquifers are in most cases found to occur in highly permeable near-vertical fractures in the low permeability basaltic crust. Therefore heat transfer in the rocks surrounding the aquifers is mainly conductive. Temperature profiles in shallow non-flowing boreholes are used to construct a two dimensional model of the temperature distribution in the vicinity of near vertical aquifers. This is done by finite element solution of the equation of heat transfer which requires knowledge of the regional temperature gradient outside the area of geothermal activity and some constraints on the temperature within the aquifers. The model is helpful in estimating dip and location of near-vertical water bearing fractures and thus in siting production wells. An example of successful use to the method and of soil temperature measurements from a geothermal field in North-Iceland is demonstrated.

An Estimate of Shallow, Low-Temperature Geothermal Resources of the United States

Energy Technology Data Exchange (ETDEWEB)

Mullane, Michelle; Gleason, Michael; Reber, Tim; McCabe, Kevin; Mooney, Meghan; Young, Katherine R.

2017-05-01

Low-temperature geothermal resources in the United States potentially hold an enormous quantity of thermal energy, useful for direct use in residential, commercial and industrial applications such as space and water heating, greenhouse warming, pool heating, aquaculture, and low-temperature manufacturing processes. Several studies published over the past 40 years have provided assessments of the resource potential for multiple types of low-temperature geothermal systems (e.g. hydrothermal convection, hydrothermal conduction, and enhanced geothermal systems) with varying temperature ranges and depths. This paper provides a summary and additional analysis of these assessments of shallow (= 3 km), low-temperature (30-150 degrees C) geothermal resources in the United States, suitable for use in direct-use applications. This analysis considers six types of geothermal systems, spanning both hydrothermal and enhanced geothermal systems (EGS). We outline the primary data sources and quantitative parameters used to describe resources in each of these categories, and present summary statistics of the total resources available. In sum, we find that low-temperature hydrothermal resources and EGS resources contain approximately 8 million and 800 million TWh of heat-in-place, respectively. In future work, these resource potential estimates will be used for modeling of the technical and market potential for direct-use geothermal applications for the U.S. Department of Energy's Geothermal Vision Study.

Economic impact of using nonmetallic materials in low to intermediate temperature geothermal well construction

Energy Technology Data Exchange (ETDEWEB)

1979-12-01

Four appendices are included. The first covers applications of low-temperature geothermal energy including industrial processes, agricultural and related processes, district heating and cooling, and miscellaneous. The second discusses hydrogeologic factors affecting the design and construction of low-temperature geothermal wells: water quality, withdrawal rate, water depth, water temperature, basic well designs, and hydrogeologic provinces. In the third appendix, properties of metallic and nonmetallic materials are described, including: specific gravity, mechanical strength properties, resistance to physical and biological attack, thermal properties of nonmetallics, fluid flow characteristics, corrosion resistance, scaling resistance, weathering resistance of nonmetallics, and hydrolysis resistance of nonmetallics. Finally, special considerations in the design and construction of low-temperature geothermal wells using nonmetallics materials are covered. These include; drilling methods, joining methods, methods of casing and screen installation, well cementing, and well development. (MHR)

Thermodynamic evaluation of geothermal energy powered hydrogen production by PEM water electrolysis

International Nuclear Information System (INIS)

Yilmaz, Ceyhun; Kanoglu, Mehmet

2014-01-01

Thermodynamic energy and exergy analysis of a PEM water electrolyzer driven by geothermal power for hydrogen production is performed. For this purpose, work is produced from a geothermal resource by means of the organic Rankine cycle; the resulting work is used as a work input for an electrolysis process; and electrolysis water is preheated by the waste geothermal water. The first and second-law based performance parameters are identified for the considered system and the system performance is evaluated. The effects of geothermal water and electrolysis temperatures on the amount of hydrogen production are studied and these parameters are found to be proportional to each other. We consider a geothermal resource at 160 °C available at a rate of 100 kg/s. Under realistic operating conditions, 3810 kW power can be produced in a binary geothermal power plant. The produced power is used for the electrolysis process. The electrolysis water can be preheated to 80 °C by the geothermal water leaving the power plant and hydrogen can be produced at a rate of 0.0340 kg/s. The energy and exergy efficiencies of the binary geothermal power plant are 11.4% and 45.1%, respectively. The corresponding efficiencies for the electrolysis system are 64.0% and 61.6%, respectively, and those for the overall system are 6.7% and 23.8%, respectively. - Highlights: • Thermodynamic analysis of hydrogen production by PEM electrolysis powered by geothermal energy. • Power is used for electrolyser; used geothermal water is for preheating electrolysis water. • Effect of geothermal water and electrolysis temperatures on the amount of hydrogen production. • Hydrogen can be produced at a rate of 0.0340 kg/s for a resource at 160 °C available at 100 kg/s. • Energy and exergy efficiencies of the overall system are 6.7% and 23.8%, respectively

Deep Geothermal Reservoir Temperatures in the Eastern Snake River Plain, Idaho using Multicomponent Geothermometry

Energy Technology Data Exchange (ETDEWEB)

Ghanashyam Neupane; Earl D. Mattson; Travis L. McLing; Carl D. Palmer; Robert W. Smith; Thomas R. Wood

2014-02-01

The U.S. Geological survey has estimated that there are up to 4,900 MWe of undiscovered geothermal resources and 92,000 MWe of enhanced geothermal potential within the state of Idaho. Of particular interest are the resources of the Eastern Snake River Plain (ESRP) which was formed by volcanic activity associated with the relative movement of the Yellowstone Hot Spot across the state of Idaho. This region is characterized by a high geothermal gradient and thermal springs occurring along the margins of the ESRP. Masking much of the deep thermal potential of the ESRP is a regionally extensive and productive cold-water aquifer. We have undertaken a study to infer the temperature of the geothermal system hidden beneath the cold-water aquifer of the ESRP. Our approach is to estimate reservoir temperatures from measured water compositions using an inverse modeling technique (RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. In the initial stages of this study, we apply the RTEst model to water compositions measured from a limited number of wells and thermal springs to estimate the regionally extensive geothermal system in the ESRP.

Neutral sodium/bicarbonate/sulfate hot waters in geothermal systems

Energy Technology Data Exchange (ETDEWEB)

Mahon, W.A.J. (Dept. of Industrial and Scientific Research, Wairakei, New Zealand); Klyen, L.E.; Rhode, M.

1980-03-01

The least understood thermal water is a near neutral water which contains varying amounts of bicarbonate and sulfate as the major anions, low concentrations of chloride (< 30 ppM) and sodium as the major cation. In the past this water has been referred to as a sodium bicarbonate water but present studies suggest that the quantities of bicarbonate and sulfate in this water type are frequently of the same order. Of particular interest is the distribution and position of the sodium/bicarbonate/sulfate water in the same and different systems. Many hot springs in Indonesia, for example, discharge water of this composition. Present studies indicate that this water type can originate from high temperature reservoirs which form the secondary steam heated part of a normal high temperature geothermal system. The hydrological conditions producing these waters in geothermal systems are investigated and the relationship between the water type and vapor dominated systems is discussed. It is suggested that the major water type occurring in the so called vapor dominated parts of geothermal systems is this water. The water does not simply represent steam condensate, rather it consists essentially of meteoric water which has been steam heated. The water composition results from the interaction of carbon dioxide and hydrogen sulfide with meteoric water and the rocks confining this water in the aquifer.

Water-related constraints to the development of geothermal electric generating stations

Energy Technology Data Exchange (ETDEWEB)

Robertson, R.C.; Shepherd, A.D.; Rosemarin, C.S.; Mayfield, M.W.

1981-06-01

The water-related constraints, which may be among the most complex and variable of the issues facing commercialization of geothermal energy, are discussed under three headings: (1) water requirements of geothermal power stations, (2) resource characteristics of the most promising hydrothermal areas and regional and local water supply situations, and (3) legal issues confronting potential users of water at geothermal power plants in the states in which the resource areas are located. A total of 25 geothermal resource areas in California, New Mexico, Oregon, Idaho, Utah, Hawaii, and Alaska were studied. Each had a hydrothermal resource temperature in excess of 150/sup 0/C (300/sup 0/F) and an estimated 30-year potential of greater than 100-MW(e) capacity.

Off-design performance analysis of Kalina cycle for low temperature geothermal source

International Nuclear Information System (INIS)

Li, Hang; Hu, Dongshuai; Wang, Mingkun; Dai, Yiping

2016-01-01

Highlights: • The off-design performance analysis of Kalina cycle is conducted. • The off-design models are established. • The genetic algorithm is used in the design phase. • The sliding pressure control strategy is applied. - Abstract: Low temperature geothermal sources with brilliant prospects have attracted more and more people’s attention. Kalina cycle system using ammonia water as working fluid could exploit geothermal energy effectively. In this paper, the quantitative analysis of off-design performance of Kalina cycle for the low temperature geothermal source is conducted. The off-design models including turbine, pump and heat exchangers are established preliminarily. Genetic algorithm is used to maximize the net power output and determine the thermodynamic parameters in the design phase. The sliding pressure control strategy applied widely in existing Rankine cycle power plants is adopted to response to the variations of geothermal source mass flow rate ratio (70–120%), geothermal source temperature (116–128 °C) and heat sink temperature (0–35 °C). In the off-design research scopes, the guidance for pump rotational speed adjustment is listed to provide some reference for off-design operation of geothermal power plants. The required adjustment rate of pump rotational speed is more sensitive to per unit geothermal source temperature than per unit heat sink temperature. Influence of the heat sink variation is greater than that of the geothermal source variation on the ranges of net power output and thermal efficiency.

Can high temperature steam electrolysis function with geothermal heat?

International Nuclear Information System (INIS)

Sigurvinsson, J.; Mansilla, C.; Werkoff, F.; Lovera, P.

2007-01-01

It is possible to improve the performance of electrolysis processes by operating at a high temperature. This leads to a reduction in electricity consumption but requires a part of the energy necessary for the dissociation of water to be in the form of thermal energy. Iceland produces low cost electricity and very low cost geothermal heat. However, the temperature of geothermal heat is considerably lower than the temperature required at the electrolyser's inlet, making heat exchangers necessary to recuperate part of the heat contained in the gases at the electrolyser's outlet. A techno-economic optimisation model devoted to a high-temperature electrolysis (HTE) process which includes electrolysers as well as a high temperature heat exchanger network was created. Concerning the heat exchangers, the unit costs used in the model are based on industrial data. For the electrolyser cells, the unit cost scaling law and the physical sub-model we used were formulated using analogies with solid oxide fuel cells. The method was implemented in a software tool, which performs the optimisation using genetic algorithms. The first application of the method is done by taking into account the prices of electricity and geothermal heat in the Icelandic context. It appears that even with a geothermal temperature as low as 230 degrees C, the HTE could compete with alkaline electrolysis. (authors)

FY 1993 report on the survey of geothermal development promotion. Survey of geothermal water (No.36 - Amemasu-dake area); 1993 nendo chinetsu kaihatsu sokushin chosa. Nessui no chosa hokokusho (No.36 Amemasu dake chiiki)

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-01-01

As a part of the survey of geothermal development promotion in FY 1993, survey of geothermal fluid was made using a precise structure drilling well N5-AM-5 as exploration well in the Amemasu-dake area, Hokkaido. The induced jetting of geothermal fluid was carried out by the Swabbing method in the total number of times of 185 in 11 days at 10-20 times/day, but did not result in the jetting of geothermal water. The sampling of geothermal water was conducted by guiding the geothermal water that overflowed the guide pipe to the tank. The temperature of geothermal water indicated approximately 20 degrees C in the 1st time and 40-60 degrees C in and after the 2nd time every day. The electric conductivity of geothermal water was 2.033 mS/cm, chlorine ion concentration was 420-500 ppm, and pH value was 7.17-7.72. As a result of the survey, it was presumed that the geothermal water of this well originated in the meteoric water around the area and formed slightly supported by emitted volcanic matters. As to the geochemical temperature, the silica temperature indicated about 120 degrees C and the alkali ratio temperature did about 180 degrees C. It was considered that there possibly existed geothermal reservoirs of approximately 180 degrees C in alkali ratio temperature around the well. (NEDO)

Studies of geothermal background and isotopic geochemistry of thermal waters in Jiangxi Province

International Nuclear Information System (INIS)

Zhou Wenbin; Sun Zhanxue; Li Xueli; Shi Weijun

1996-10-01

The terrestrial heat flow measurement, isotope and geochemical techniques have been systematically applied to the geothermal systems in Jiangxi Province. Results show that the thermal waters in the study area all belong to the low-medium temperature convective geothermal system, which essentially differs from high temperature geothermal systems with deep magmatic heat sources. It has been proven that the isotope and geochemical techniques are very useful and effective in geothermal exploration. (13 refs., 14 tabs., 8 figs.)

An Estimate of Shallow, Low-Temperature Geothermal Resources of the United States: Preprint

Energy Technology Data Exchange (ETDEWEB)

Mullane, Michelle; Gleason, Michael; McCabe, Kevin; Mooney, Meghan; Reber, Timothy; Young, Katherine R.

2016-10-01

Low-temperature geothermal resources in the United States potentially hold an enormous quantity of thermal energy, useful for direct use in residential, commercial and industrial applications such as space and water heating, greenhouse warming, pool heating, aquaculture, and low-temperature manufacturing processes. Several studies published over the past 40 years have provided assessments of the resource potential for multiple types of low-temperature geothermal systems (e.g. hydrothermal convection, hydrothermal conduction, and enhanced geothermal systems) with varying temperature ranges and depths. This paper provides a summary and additional analysis of these assessments of shallow (= 3 km), low-temperature (30-150 degrees C) geothermal resources in the United States, suitable for use in direct-use applications. This analysis considers six types of geothermal systems, spanning both hydrothermal and enhanced geothermal systems (EGS). We outline the primary data sources and quantitative parameters used to describe resources in each of these categories, and present summary statistics of the total resources available. In sum, we find that low-temperature hydrothermal resources and EGS resources contain approximately 8 million and 800 million TWh of heat-in-place, respectively. In future work, these resource potential estimates will be used for modeling of the technical and market potential for direct-use geothermal applications for the U.S. Department of Energy's Geothermal Vision Study.

Hydrogen and oxygen isotope ratios of geothermal waters in the southern hachimantai area

International Nuclear Information System (INIS)

Matsubaya, Osamu; Etchu, Hiroshi; Takenaka, Teruo; Yoshida, Yutaka.

1985-01-01

Geothermal waters from the Matsukawa and Kakkonda Geothermal Plants, wells at Amihari-Motoyu, and Nyuto and Tazawako areas were isotopically studied. The geothermal waters from Mutsukawa, Kakkonda and Amihari-Motoyu have hydrogen isotope ratios similar to the local meteoric waters, while have higher oxygen isotope ratios than the local meteoric waters. This relationship of hydrogen and oxygen isotope ratios, that is called ''oxygen shift'', means that these geothermal waters are meteoric waters undergone the oxygen isotope exchange with rocks at high temperature of underground. The exygen shifts are 2 -- 3 per mil in Matsukawa and Kakkonda, and 7 per mil in Amihari-Motoyu. This difference may be important to understand the processe of water-rock interaction in this area. The geothermal waters at Nyuto and Tazawako areas also show 2 -- 3 per mil oxygen shift. The steam from the Tazawako-cho well and the hot spring water form the Tsurunoyu are estimated to be vapor and liquid phases separated form a single geothermal water of NaCl type, though the hot water from the Tsurunoyu is diluted with shallow meteoric water. (author)

Hydrogeochemistry and environmental impact of geothermal waters from Yangyi of Tibet, China

Science.gov (United States)

Guo, Qinghai; Wang, Yanxin; Liu, Wei

2009-02-01

The Yangyi geothermal field, located 72 km northwest to Lhasa City, capital of Tibet, has a high reservoir temperature up to at least 207.2 °C. The geothermal waters from both geothermal wells and hot springs belong to the HCO 3 (+CO 3)-Na type. Factor analysis of all the chemical constituents shows that they can be divided into two factors: F 1 factor receives the contributions of SO 42-, Cl -, SiO 2, As, B, Na +, K +, and Li +; whereas F 2 factor is explained by HCO 3-, F -, CO 32-, Ca 2+, and Sr 2+. The F 1 factor can be regarded as an indicator of the reservoir temperature distribution at Yangyi, but its variable correlation with the results of different geothermometers (Na-K, quartz and K-Mg) does not allow one to draw further inferences. Different from F 1, the F 2 factor is an indicator of a group of hydrogeochemical processes resulting from the CO 2 pressure decrease in geothermal water during its ascent from the deep underground, including transformation of HCO 3- to CO 32-, precipitation of Ca 2+ and Sr 2+, and release of F - from some fluoride-bearing minerals of reservoir rocks. The plot of enthalpy vs. chloride, prepared on the basis of Na-K equilibrium temperatures, suggests that a parent geothermal liquid (PGL) with Cl - concentration of 185 mg/L (that of sample YYT-8) and enthalpy of 1020 J/g (corresponding to a temperature of 236-237 °C, i.e., somewhat higher than that of sample YYT-6) is present in the geothermal reservoir of the Yangyi area, below both the Qialagai valley and the Bujiemu valley, although the samples less affected by mixing and cooling (YYT-6 and YYT-7) come from the second site. The discharge of geothermal waters with high contents of toxic elements such as B, As and F into the Luolang River, the only drinking water source for local residents, has caused slight pollution of the river water. Great care should therefore be taken in the geothermal water resource management at Yangyi.

Recovery of lithium from geothermal water by amorphous hydrous aluminium oxide

International Nuclear Information System (INIS)

Wada, Hideo; Kitamura, Takao; Ooi, Kenta; Katoh, Shunsaku

1984-01-01

Effects of chemical composition, temperature, and lithium concentration of geothermal water on lithium recovery by amorphous hydrous aluminium oxide (a-HAO) were investigated in order to evaluate the feasibility of this process. The results are summarized as follows: (1) Among various chemical consituents in geothermal water, silica interfered with the lithium adsorption. The lithium uptake decreased when silica concentration exceeded 73 mg/l under 100 mg/50 ml a-HAO to solution ratio. (2) The lithium uptake decreased with an increase of adsorption temperature and was not observed above 40 deg C. At higher temperature, the crystallization of a-HAO to bayerite occurred prior to lithium adsorption. (3) The lithium uptake increased with an increase of lithium concentration. Lithium uptake comparable with lithium contents in lithium ores was obtained at the lithium concentration of 30 mg/l at 20 deg C. These results show that a-HAO is applicable to collect lithium from geothermal water if silica can be removed before lithium adsorption. (author)

Low-temperature geothermal resources of Washington

Energy Technology Data Exchange (ETDEWEB)

Schuster, J.E. [Washington State Dept. of Natural Resources, Olympia, WA (United States). Div. of Geology and Earth Resources; Bloomquist, R.G. [Washington State Energy Office, Olympia, WA (United States)

1994-06-01

This report presents information on the location, physical characteristics, and water chemistry of low-temperature geothermal resources in Washington. The database includes 941 thermal (>20C or 68F) wells, 34 thermal springs, lakes, and fumaroles, and 238 chemical analyses. Most thermal springs occur in the Cascade Range, and many are associated with stratovolcanoes. In contrast, 97 percent of thermal wells are located in the Columbia Basin of southeastern Washington. Some 83.5 percent are located in Adams, Benton, Franklin, Grant, Walla Walla, and Yakima Counties. Yakima County, with 259 thermal wells, has the most. Thermal wells do not seem to owe their origin to local sources of heat, such as cooling magma in the Earth`s upper crust, but to moderate to deep circulation of ground water in extensive aquifers of the Columbia River Basalt Group and interflow sedimentary deposits, under the influence of a moderately elevated (41C/km) average geothermal gradient.

Geochemical and isotopic evidence on the recharge and circulation of geothermal water in the Tangshan Geothermal System near Nanjing, China: implications for sustainable development

Science.gov (United States)

Lu, Lianghua; Pang, Zhonghe; Kong, Yanlong; Guo, Qi; Wang, Yingchun; Xu, Chenghua; Gu, Wen; Zhou, Lingling; Yu, Dandan

2018-01-01

Geothermal resources are practical and competitive clean-energy alternatives to fossil fuels, and study on the recharge sources of geothermal water supports its sustainable exploitation. In order to provide evidence on the recharge source of water and circulation dynamics of the Tangshan Geothermal System (TGS) near Nanjing (China), a comprehensive investigation was carried out using multiple chemical and isotopic tracers (δ2H, δ18O, δ34S, 87Sr/86Sr, δ13C, 14C and 3H). The results confirm that a local (rather than regional) recharge source feeds the system from the exposed Cambrian and Ordovician carbonate rocks area on the upper part of Tangshan Mountain. The reservoir temperature up to 87 °C, obtained using empirical as well as theoretical chemical geothermometers, requires a groundwater circulation depth of around 2.5 km. The temperature of the geothermal water is lowered during upwelling as a consequence of mixing with shallow cold water up to a 63% dilution. The corrected 14C age shows that the geothermal water travels at a very slow pace (millennial scale) and has a low circulation rate, allowing sufficient time for the water to become heated in the system. This study has provided key information on the genesis of TGS and the results are instructive to the effective management of the geothermal resources. Further confirmation and even prediction associated with the sustainability of the system could be achieved through continuous monitoring and modeling of the responses of the karstic geothermal reservoir to hot-water mining.

Relation between 1m depth temperature and average geothermal gradient at 75cm depth in geothermal fields

OpenAIRE

江原, 幸雄

2009-01-01

Shallow ground temperatures such as 1m depth temperature have been measured to delineate thermal anomalies of geothermal fields and also to estimate heat discharge rates from geothermal fields. As a result, a close linear relation between 1m depth temperature and average geothermal gradient at 75cm depth has been recognized in many geothermal fields and was used to estimate conductive heat discharge rates. However, such a linear relation may show that the shallow thermal regime in geothermal ...

Geothermal system 'Toplets' and geothermal potential of Dojran region

International Nuclear Information System (INIS)

Karakashev, Deljo; Delipetrov, Marjan; Jovanov, Kosta

2008-01-01

The Toplets geothermal spring that expands into a wide geothermal net in the watershed of Lake Dojran along the geophysical exploration work carried out in the terrain, indicated the presence of a significant geothermal potential in the region. In the future it may become the major factor for the development of vegetable growing, the use of the medicinal properties of the mineral spas and tourism as well as the prosperity of the region. Water temperature in Lake Dojran amounts 15°C to 28°C during the year that is mach higher compared with the temperature of water lakes in neighbouring Greece. This indicates that beneath Lake Dojran there are other geothermal sources that replenish the lake with thermal water. Such manifestations of geothermal energy in the region along with other thermal phenomena speak for the presence of large reserves of geothermal energy in the Dojran depression. (Author)

Geothermal system 'Toplets' and geothermal potential of Dojran region

International Nuclear Information System (INIS)

Karakashev, Deljo; Delipetrov, Marjan; Jovanov, Kosta

2007-01-01

The Toplets geothermal spring that expands into a wide geothermal net in the watershed of Lake Dojran along the geophysical exploration work carried out in the terrain, indicated the presence of a significant geothermal potential in the region. In the future it may become the major factor for the development of vegetable growing, the use of the medicinal properties of the mineral spas and tourism as well as the prosperity of the region. Water temperature in Lake Dojran amounts 15°C to 28°C during the year that is mach higher compared with the temperature of water lakes in neighbouring Greece. This indicates that beneath Lake Dojran there are other geothermal sources that replenish the lake with thermal water. Such manifestations of geothermal energy in the region along with other thermal phenomena speak for the presence of large reserves of geothermal energy in the Dojran depression. (Author)

Multi-purpose utilization and development of geothermal water: European overseas investigation

Energy Technology Data Exchange (ETDEWEB)

Ochiai, T [Natl. Research Institute of Agricultural Engineering, Japan

1978-01-01

In order to investigate the agricultural utilization of geothermal waters, a fact-finding team visited France, Italy, Iceland, and Turkey. In France, it was seen that the development and utilization of geothermal waters is in accord with Japanese practices. The production and reinjection wells are drilled to a depth of 1800 m. They are spaced about 10 m apart at the surface and about 800 m apart at the bottom. This is accomplished by drilling at an angle. The hot water is produced at a rate of about 90 t/h. It is passed through a heat exchanger where it warms surface water to about 70/sup 0/C. The warmed water is then supplied for purposes of district heating, greenhouse culture, and fish farming. The used hot water is then returned to the producing stratum via the reinjection well. Iceland began the production of hot geothermal water in 1925, and, at present, 99% of the city of Reykjavik is heated geothermally. The deepest production wells at Reykjavik reach 2000 m. The water produced has a temperature of 90-103/sup 0/C, and is also used for agricultural purposes.

Hydrochemical and isotopic (2H, 18O and 37Cl) constraints on evolution of geothermal water in coastal plain of Southwestern Guangdong Province, China

Science.gov (United States)

Chen, Liuzhu; Ma, Teng; Du, Yao; Xiao, Cong; Chen, Xinming; Liu, Cunfu; Wang, Yanxin

2016-05-01

Geothermal energy is abundant in Guangdong Province of China, however, majority of it is still unexploited. To take full advantage of this energy, it is essential to know the information of geothermal system. Here, physical parameters such as pH and temperature, major ion (Na+, Ca2 +, Mg2 +, Cl-, SO42 - and HCO3-), trace elements (Br-, Sr2 +, Li+ and B3 +) and stable isotopes (2H, 18O and 37Cl) in geothermal water, non-geothermal water (river water, cold groundwater) and seawater were used to identify the origin and evolution of geothermal water in coastal plain of Southwest of Guangdong. Two separate groups of geothermal water have been identified in study area. Group A, located in inland of study area, is characterized by Na+ and HCO3-. Group B, located in coastal area, is characterized by Na+ and Cl-. The relationships of components vs. Cl for different water samples clearly suggest the hydrochemical differences caused by mixing with seawater and water-rock interactions. It's evident that water-rock interactions under high temperature make a significant contribution to hydrochemistry of geothermal water for both Group A and Group B. Besides, seawater also plays an important role during geothermal water evolution for Group B. Mixing ratios of seawater with geothermal water for Group B are calculated by Cl and Br binary diagram, the estimated results show that about < 1% to < 35% of seawater has mixed into geothermal water, and seawater might get into the geothermal system by deep faults. Molar Na/Cl ratios also support these two processes. Geothermal and non-geothermal water samples plot around GMWL in the δ2H vs. δ18O diagram, indicating that these samples have a predominant origin from meteoric water. Most of geothermal water samples display δ37Cl values between those of the non-geothermal water and seawater samples, further reveals three sources of elements supply for geothermal water, including atmospheric deposition, bedrocks and seawater, which show a

Hydrochemical characterization of a mine water geothermal energy resource in NW Spain.

Science.gov (United States)

Loredo, C; Ordóñez, A; Garcia-Ordiales, E; Álvarez, R; Roqueñi, N; Cienfuegos, P; Peña, A; Burnside, N M

2017-01-15

Abandoned and flooded mine networks provide underground reservoirs of mine water that can be used as a renewable geothermal energy source. A complete hydrochemical characterization of mine water is required to optimally design the geothermal installation, understand the hydraulic behavior of the water in the reservoir and prevent undesired effects such as pipe clogging via mineral precipitation. Water pumped from the Barredo-Figaredo mining reservoir (Asturias, NW Spain), which is currently exploited for geothermal use, has been studied and compared to water from a separate, nearby mountain mine and a river that receives mine water discharge and partially infiltrates into the mine workings. Although the hydrochemistry was altered during the flooding process, the deep mine waters are currently near neutral, net alkaline, high metal waters of Na-HCO 3 type. Isotopic values suggest that mine waters are closely related to modern meteoric water, and likely correspond to rapid infiltration. Suspended and dissolved solids, and particularly iron content, of mine water results in some scaling and partial clogging of heat exchangers, but water temperature is stable (22°C) and increases with depth, so, considering the available flow (>100Ls -1 ), the Barredo-Figaredo mining reservoir represents a sustainable, long-term resource for geothermal use. Copyright © 2016 Elsevier B.V. All rights reserved.

Hydrogeochemistry Characteristics and Daily Variation of Geothermal Water in the Moxi Fault,Southwest of China

Science.gov (United States)

Qi, Jihong; Xu, Mo; An, Chenjiao; Zhang, Yunhui; Zhang, Qiang

2017-04-01

The Xianshuihe Fault with frequent earthquakes activities is the regional deep fault in China. The Moxi Fault is the southern part of the Xianshuihe Fault, where the strong activities of geothermal water could bring abundant information of deep crust. In this article, some typical geothermal springs were collected along the Moxi fault from Kangding to Shimian. Using the the Na-K-Mg equilibrium diagram, it explains the state of water-rock equilibrium, and estimates the reservoir temperature basing appropriate geothermometers. Basing on the relationship between the enthalpy and chlorine concentration of geothermal water, it analyze the mixing progress of thermal water with shallow groundwater. Moreover, the responses of variation of geothermal water to the solid tides are considered to study the hydrothermal activities of this fault. The Guanding in Kangding are considered as the center of the geothermal system, and the hydrothermal activities decrease southward extending. Geothermal water maybe is heated by the deep heat source of the Himalayan granites, while the springs in the south area perform the mixture with thermal water in the sub-reservoir of the Permian crystalline limestone. It improves the research of hydrothermal activities in the Moxi Fault, meanwhile using the variation of geothermal water maybe become a important method to study the environment of deep earth in the future.

Lithium Isotopes in Geothermal Fluids from Iceland

Science.gov (United States)

Millot, R.; Asmundsson, R.; Sanjuan, B.

2008-12-01

One of the main objectives of the HITI project (HIgh Temperature Instruments for supercritical geothermal reservoir characterization and exploitation), partially funded by the European Union, is to develop methods to characterize the reservoir and fluids of deep and very high temperature geothermal systems. The chemical composition of geothermal waters in terms of major and trace elements is related to the temperature, the degree of water/rock interaction and the mineralogical assemblage of the bedrock. Traditional geothermometers, such as silica, Na-K, Na-K-Ca or K-Mg applied to geothermal waters, make it possible to estimate the temperature at depth of the reservoir from which the waters are derived. However, the values estimated for deep temperature are not always concordant. The chemical geothermometer Na/Li which presents the singularity of associating two chemical elements, one a major element (sodium) and the other a trace element (Li), can be also used and gives an additional temperature estimation. The primary objective of this work was to better understand the behavior of this last geothermometer using the isotopic systematics of Li in order to apply it at very high temperature Icelandic geothermal systems. One particularly important aspect was to establish the nature, extent and mechanism of Li isotope fractionation between 100 and 350°C during water/rock interaction. For that purpose, we measured Li isotopes of about 25 geothermal waters from Iceland by using a Neptune MC-ICP-MS that enabled the analysis of Li isotopic ratios in geothermal waters with a level of precision of ±0.5‰ (2 standard deviations) on quantities of 10-50 ng of Li. Geothermal waters from Reykjanes, Svartsengi, Nesjavellir, Hveragerdi, Namafjall and Krafla geothermal systems were studied and particular emphasis was placed on the characterization of the behavior of Li isotopes in this volcanic context at high temperature with or without the presence of seawater during water

Sperry Low Temperature Geothermal Conversion System, Phase 1 and Phase 2. Volume 3: Systems description

Science.gov (United States)

Matthews, H. B.

The major fraction of hydrothermal resources with the prospect of economic usefulness for the generation of electricity are in the 300(0)F to 425(0)F temperature range. Cost effective conversion of the geothermal energy to electricity requires new ideas to improve conversion efficiency, enhance brine flow, reduce plant costs, increase plant availability, and shorten the time between investment and return. The problems addressed are those inherent in the geothermal environment, in the binary fluid cycle, in the difficulty of efficiently converting the energy of a low temperature resource, and in geothermal economics some of these problems are explained. The energy expended by the down hole pump; the difficulty in designing reliable down hole equipment; fouling of heat exchanger surfaces by geothermal fluids; the unavailability of condenser cooling water at most geothermal sites; the large portion of the available energy used by the feed pump in a binary system; the pinch effect, a loss in available energy in transferring heat from water to an organic fluid; flow losses in fluids that carry only a small amount of useful energy to begin with; high heat exchanger costs, the lower the temperature interval of the cycle, the higher the heat exchanger costs in $/kW; the complexity and cost of the many auxiliary elements of proposed geothermal plants; and the unfortunate cash flow vs. investment curve caused by the many years of investment required to bring a field into production before any income is realized.

Geothermal energy utilization in Russia

Energy Technology Data Exchange (ETDEWEB)

Svalova, V. [Institute of Environmental Geoscience, RAS, Moscow (Russian Federation)

2011-07-01

Geothermal energy use is the way to clean, sustainable energy development for the world. Russia has rich high and low temperature geothermal resources and is making progress using them - mostly with low-temperature geothermal resources and heat pumps This is optimal for many regions of Russia -in the European part, in the Urals and others. Electricity is generated by some geothermal power plants (GeoPP) only in the Kamchatka Peninsula and Kuril Islands There are two possible ways of using geothermal resources, depending on the properties of thermal waters heat/power and mineral extraction. The mineral-extraction direction is basic for geothermal waters, which contain valuable components in industrial quantities The most significant deposits of thermal waters represent the brines containing from 35 up to 400 and more g/l of salts. These are the minerals of many chemical dements. (author)

Use of Low-Temperature Geothermal Energy for Desalination in the Western United States

Energy Technology Data Exchange (ETDEWEB)

Turchi, Craig S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Akar, Sertac [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cath, Tzahi [Colorado School of Mines, Golden, CO (United States); Vanneste, Johan [Colorado School of Mines, Golden, CO (United States); Geza, Mengistu [Colorado School of Mines, Golden, CO (United States)

2015-11-01

This joint project between the National Renewable Energy Laboratory and the Colorado School of Mines has examined the potential of using low-temperature geothermal resources for desalination. The temperature range in question is not well suited for electricity generation, but can be used for direct heating. Accordingly, the best integration approaches use thermal desalination technologies such as multi-effect distillation (MED) or membrane distillation (MD), rather than electric-driven technologies such as reverse osmosis (RO). The examination of different desalination technologies led to the selection of MD for pairing with geothermal energy. MD operates at near-ambient pressure and temperatures less than 100°C with hydrophobic membranes. The technology is modular like RO, but the equipment costs are lower. The thermal energy demands of MD are higher than MED, but this is offset by an ability to run at lower temperatures and a low capital cost. Consequently, a geothermal-MD system could offer a low capital cost and, if paired with low-cost geothermal energy, a low operating cost. The target product water cost is $1.0 to $1.5 per cubic meter depending on system capacity and the cost of thermal energy.

Estimation of geothermal gradients from single temperature log-field cases

International Nuclear Information System (INIS)

Kutasov, I M; Eppelbaum, L V

2009-01-01

A geothermal gradient is one of the most frequently used parameters in logging geophysics. However, the drilling process greatly disturbs the temperature of the formations around the wellbore. For this reason, in order to determine with the required accuracy the formation temperatures and geothermal gradients, a certain length of shut-in time is required. It was shown earlier (Kutasov 1968 Freiberger Forshungshefte C 238 55–61, 1987 Geothermics 16 467–72) that at least two transient temperature surveys are needed to determine the geothermal gradient with adequate accuracy. However, in many cases only one temperature log is conducted in a shut-in borehole. For these cases, we propose an approximate method for the estimation of the geothermal gradient. The utilization of this method is demonstrated on four field examples

Potential effects of the Hawaii Geothermal Project on ground-water resources on the island of Hawaii

Science.gov (United States)

Sorey, M.L.; Colvard, E.M.

1994-01-01

In 1990, the State of Hawaii proposed the Hawaii Geothermal Project for the development of as much as 500 MW of electric power from the geothermal system in the East Rift Zone of Kilauea Volcano. This report uses data from 31 wells and 8 springs to describe the properties of the ground-water system in and adjacent to the East Rift Zone. Potential effects of this project on ground-water resources are also discussed. Data show differences in ground-water chemistry and heads within the study area that appear to be related to mixing of waters of different origins and ground-water impoundment by volcanic dikes. East of Pahoa, the ground-water system within the rift is highly transmissive and receives abundant recharge from precipitation; therefore, the pumping of freshwater to support geothermal development in that part of the rift zone would have a minimal effect on ground-water levels. To the southwest of Pahoa, dike impoundment reduces the transmissivity of the ground-water system to such an extent that wells might not be capable of supplying sufficient fresh water to support geothermal operations. Contamination of ground-water resources by accidental release of geothermal fluids into shallow aquifers is possible because of corrosive conditions in the geothermal wells, potential well blowouts, and high ground-water velocities in parts of the region. Hydrologic monitoring of water level, temperature, and chemistry in observation wells should continue throughout development of geothermal resources for the Hawaii Geothermal Project for early detection of leakage and migration of geothermal fluids within the groundwater system.

Low temperature geothermal systems in carbonate-evaporitic rocks: Mineral equilibria assumptions and geothermometrical calculations. Insights from the Arnedillo thermal waters (Spain).

Science.gov (United States)

Blasco, Mónica; Gimeno, María J; Auqué, Luis F

2018-02-15

Geothermometrical calculations in low-medium temperature geothermal systems hosted in carbonate-evaporitic rocks are complicated because 1) some of the classical chemical geothermometers are, usually, inadequate (since they were developed for higher temperature systems with different mineral-water equilibria at depth) and 2) the chemical geothermometers calibrated for these systems (based on the Ca and Mg or SO 4 and F contents) are not free of problems either. The case study of the Arnedillo thermal system, a carbonate-evaporitic system of low temperature, will be used to deal with these problems through the combination of several geothermometrical techniques (chemical and isotopic geothermometers and geochemical modelling). The reservoir temperature of the Arnedillo geothermal system has been established to be in the range of 87±13°C being the waters in equilibrium with respect to calcite, dolomite, anhydrite, quartz, albite, K-feldspar and other aluminosilicates. Anhydrite and quartz equilibria are highly reliable to stablish the reservoir temperature. Additionally, the anhydrite equilibrium explains the coherent results obtained with the δ 18 O anhydrite - water geothermometer. The equilibrium with respect to feldspars and other aluminosilicates is unusual in carbonate-evaporitic systems and it is probably related to the presence of detrital material in the aquifer. The identification of the expected equilibria with calcite and dolomite presents an interesting problem associated to dolomite. Variable order degrees of dolomite can be found in natural systems and this fact affects the associated equilibrium temperature in the geothermometrical modelling and also the results from the Ca-Mg geothermometer. To avoid this uncertainty, the order degree of the dolomite present in the Arnedillo reservoir has been determined and the results indicate 18.4% of ordered dolomite and 81.6% of disordered dolomite. Overall, the results suggest that this multi

Modeling research in low-medium temperature geothermal field, Tianjin

Institute of Scientific and Technical Information of China (English)

WANG; Kun(王坤); LI; Chunhua(李春华)

2002-01-01

The geothermal reservoir in Tianjin can be divided into two parts: the upper one is the porous medium reservoir in the Tertiary system; the lower one includes the basement reservoir in Lower Paleozoic and Middle-Upper Proterozoic. Hot springs are exposed in the northern mountain and confined geothermal water is imbedded in the southern plain. The geothermal reservoir is incised by several fractures. In recent years, TDS of the geothermal water have gone up along with the production rate increasing, along the eastern fracture zone (Cangdong Fracture and West Baitangkou Fracture). This means that the northern fracture system is the main seepage channel of the deep circulation geothermal water, and the reservoir has good connection in a certain area and definite direction. The isotopic research about hydrogen and carbon chronology indicates that the main recharge period of geothermal water is the Holocene Epoch, the pluvial and chilly period of 20 kaBP. The karst conduits in weathered carbonate rocks of the Proterozoic and Lower Paleozoic and the northeast regional fracture system are the main feeding channels of Tianjin geothermal water. Since the Holocene epoch, the geothermal water stayed at a sealed warm period. The tracer test in WR45 doublet system shows that the tracer test is a very effective measure for understanding the reservoir's transport nature and predicting the cooling time and transport velocity during the reinjection. 3-D numerical simulation shows that if the reinjection well keeps a suitable distance from the production well, reinjection will be a highly effective measure to extract more thermal energy from the rock matrix. The cooling of the production well will not be a problem.

Hydrochemistry and geothermometrical modeling of low-temperature Panticosa geothermal system (Spain)

Science.gov (United States)

Asta, Maria P.; Gimeno, Maria J.; Auqué, Luis F.; Gómez, Javier; Acero, Patricia; Lapuente, Pilar

2012-08-01

The chemical characteristics of the low-temperature geothermal system of Panticosa (Spain) were investigated in order to determine the water temperature at the reservoir and to identify the main geochemical processes that affect the water composition during the ascent of the thermal waters. In general, the studied waters are similar to other geothermal systems in the Pyrenees, belonging to the group of granite-related alkaline thermal waters (high pH, low total dissolved solids, very low magnesium concentration, and sodium as the dominant cation). According to the alkaline pH of these waters, they have a very low CO2 partial pressure, bicarbonate is the dominant anion and silica is partially ionized as H3SiO4-. The unusually active acid-base pairs (HCO3-/CO32 - and, mainly, H4SiO4/H3SiO4-) act as homogeneous pH buffers and contribute to the total alkalinity in these alkaline waters. On the basis of the study of the conservative elements, a mixing process between a hot and a cold end-member has been identified. Additionally, in order to determinate the water temperature at the reservoir, several geothermometric techniques have been applied, including both geothermometrical modeling and classical geothermometrical calculations. The geothermometrical modeling seems to indicate that thermal waters re-equilibrate with respect to calcite and kaolinite during their ascent to the surface. Modeling results suggest that these thermal waters would be in equilibrium with respect to albite, K-feldspar, quartz, calcite, kaolinite and zoisite at a similar temperature of 90 ± 20 °C in the reservoir, which is in good agreement with the results obtained by applying the classical geothermometers.

Feasibility study and energy efficiency estimation of geothermal power station based on medium enthalpy water

Directory of Open Access Journals (Sweden)

Borsukiewicz-Gozdur Aleksandra

2007-01-01

Full Text Available In the work presented are the results of investigations regarding the effectiveness of operation of power plant fed by geothermal water with the flow rate of 100, 150, and 200 m3/h and temperatures of 70, 80, and 90 °C, i. e. geothermal water with the parameters available in some towns of West Pomeranian region as well as in Stargard Szczecinski (86.4 °C, Poland. The results of calculations regard the system of geothermal power plant with possibility of utilization of heat for technological purposes. Analyzed are possibilities of application of different working fluids with respect to the most efficient utilization of geothermal energy. .

Water Use in Enhanced Geothermal Systems (EGS): Geology of U.S. Stimulation Projects, Water Costs, and Alternative Water Source Policies

Energy Technology Data Exchange (ETDEWEB)

Harto, C. B. [Argonne National Lab. (ANL), Argonne, IL (United States); Schroeder, J. N. [Argonne National Lab. (ANL), Argonne, IL (United States); Horner, R. M. [Argonne National Lab. (ANL), Argonne, IL (United States); Patton, T. L. [Argonne National Lab. (ANL), Argonne, IL (United States); Durham, L. A. [Argonne National Lab. (ANL), Argonne, IL (United States); Murphy, D. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Clark, C. E. [Argonne National Lab. (ANL), Argonne, IL (United States)

2014-10-01

According to the Energy Information Administration (EIA) of the U.S. Department of Energy (DOE), geothermal energy generation in the United States is projected to more than triple by 2040 (EIA 2013). This addition, which translates to more than 5 GW of generation capacity, is anticipated because of technological advances and an increase in available sources through the continued development of enhanced geothermal systems (EGSs) and low-temperature resources (EIA 2013). Studies have shown that air emissions, water consumption, and land use for geothermal electricity generation have less of an impact than traditional fossil fuel–based electricity generation; however, the long-term sustainability of geothermal power plants can be affected by insufficient replacement of aboveground or belowground operational fluid losses resulting from normal operations (Schroeder et al. 2014). Thus, access to water is therefore critical for increased deployment of EGS technologies and, therefore, growth of the geothermal sector. This paper examines water issues relating to EGS development from a variety of perspectives. It starts by exploring the relationship between EGS site geology, stimulation protocols, and below ground water loss, which is one of the largest drivers of water consumption for EGS projects. It then examines the relative costs of different potential traditional and alternative water sources for EGS. Finally it summarizes specific state policies relevant to the use of alternative water sources for EGS, and finally explores the relationship between EGS site geology, stimulation protocols, and below ground water loss, which is one of the largest drivers of water consumption for EGS projects.

Geothermal System Extensions

Energy Technology Data Exchange (ETDEWEB)

Gunnerson, Jon [Boise City Corporation, ID (United States); Pardy, James J. [Boise City Corporation, ID (United States)

2017-09-30

This material is based upon work supported by the Department of Energy under Award Number DE-EE0000318. The City of Boise operates and maintains the nation’s largest geothermal heating district. Today, 91 buildings are connected, providing space heating to over 5.5 million square feet, domestic water heating, laundry and pool heating, sidewalk snowmelt and other related uses. Approximately 300 million gallons of 177°F geothermal water is pumped annually to buildings and institutions located in downtown Boise. The closed loop system returns all used geothermal water back into the aquifer after heat has been removed via an Injection Well. Water injected back into the aquifer has an average temperature of 115°F. This project expanded the Boise Geothermal Heating District (Geothermal System) to bring geothermal energy to the campus of Boise State University and to the Central Addition Eco-District. In addition, this project also improved the overall system’s reliability and increased the hydraulic capacity.

Subsurface temperatures and geothermal gradients on the North Slope, Alaska

Science.gov (United States)

Collett, Timothy S.; Bird, Kenneth J.; Magoon, Leslie B.

1989-01-01

Geothermal gradients as interpreted from a series of high-resolution stabilized well-bore-temperature surveys from 46 North Slope, Alaska, wells vary laterally and vertically throughout the near-surface sediment (0-2,000 m). The data from these surveys have been used in conjunction with depths of ice-bearing permafrost, as interpreted from 102 well logs, to project geothermal gradients within and below the ice-bearing permafrost sequence. The geothermal gradients calculated from the projected temperature profiles are similar to the geothermal gradients measured in the temperature surveys. Measured and projected geothermal gradients in the ice-bearing permafrost sequence range from 1.5??C/100m in the Prudhoe Bay area to 5.1??C/100m in the National Petroleum Reserve in Alaska (NPRA).

Geochemical study of water-rock interaction processes on geothermal systems of alkaline water in granitic massif

International Nuclear Information System (INIS)

Buil gutierrez, B.; Garcia Sanz, S.; Lago San Jose, M.; Arranz Yague, E.; Auque Sanz, L.

2002-01-01

The study of geothermal systems developed within granitic massifs (with alkaline waters and reducing ORP values) is a topic of increasing scientific interest. These systems are a perfect natural laboratory for studying the water-rock interaction processes as they are defined by three main features: 1) long residence time of water within the system, 2) temperature in the reservoir high enough to favour reaction kinetics and finally, 3) the comparison of the chemistry of the incoming and outgoing waters of the system allows for the evaluation of the processes that have modified the water chemistry and its signature, The four geothermal systems considered in this paper are developed within granitic massifs of the Spanish Central Pyrenes; these systems were studied from a geochemical point of view, defining the major, trace and REE chemistry of both waters and host rocks and then characterizing the composition and geochemical evolution of the different waters. Bicarbonate-chloride-sodic and bicarbonate-sodic compositions are the most representative of the water chemistry in the deep geothermal system, as they are not affected by secondary processes (mixing, conductive cooling, etc). (Author)

Geothermal resource and utilization in Bulgaria

International Nuclear Information System (INIS)

Bojadgieva, K.; Benderev, A.

2011-01-01

Bulgarian territory is rich in thermal water of temperature in the range of 20 - 100 o C. The highest water temperature (98 o C) is measured in Sapareva banya geothermal reservoir. Electricity generation from geothermal water is not currently available in the country. The major direct thermal water use nowadays covers: balneology, space heating and air-conditioning, domestic hot water supply, greenhouses, swimming pools, bottling of potable water and geothermal ground source heat pumps (GSHP). The total installed capacity amounts to about 77.67 MW (excl. GSHP) and the produced energy is 1083.89 TJ/year. Two applications - balneology and geothermal ground source heat pumps show more stable development during the period of 2005 - 2010. The update information on the state-owned hydrothermal fields is based on issued permits and concessions by the state.

California low-temperature geothermal resources update: 1993

Energy Technology Data Exchange (ETDEWEB)

Youngs, L.G.

1994-12-31

The US Department of Energy -- Geothermal Division (DOE/GD) recently sponsored the Low-Temperature Geothermal Resources and Technology Transfer Program to bring the inventory of the nation`s low- and moderate-temperature geothermal resources up to date and to encourage development of the resources. The Oregon Institute of Technology, Geo-Heat Center (OIT/GHC) and the University of Utah Research Institute (UURI) established subcontracts and coordinated the project with the state resource teams from the western states that participated in the program. The California Department of Conservation, Division of Mines and Geology (DMG) entered into contract numbered 1092--023(R) with the OIT/GHC to provide the California data for the program. This report is submitted in fulfillment of that contract.

FY 1990 report on the survey of geothermal development promotion. Survey of geothermal water (No.34 - Kaminoyu/Santai area); 1990 nendo chinetsu kaihatsu sokushin chosa. Nessui no chosa hokokusho (No.34 Kaminoyu Santai chiiki)

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-12-01

For the contribution to elucidation of the structure of geothermal reservoir in the Kaminoyu/Santai area in the southwest part of Hokkaido, jetting test/sampling of geothermal fluid/analysis of properties were carried out in Structural Drilling Well N2-KS-2. The induced jetting of N2-KS-2 was conducted by the air lift method in consideration of the well temperature, state of lost circulation while drilling and results of the water pouring test. As a result, the mean jetting amount of geothermal water was 202.4L/min. The total pumping amount was 559kL, which is equal to approximately 119 times as much as the volume of well. The maximum temperature was 95.9 degrees C, resulting in no steam jetting. The pH of geothermal water was 7.41-8.44, electric conductivity was 9,620-10,450 {mu}s/cm, and the Cl ion concentration was 2,204-2,545 mg/L, which are almost stable. Properties of geothermal water is classified into an alkalescent CL-SO{sub 4} type. As a result of the study, the geothermal reservoir of N2-KS-2 is basically formed by a mechanism of a mixture of the surface water and the deep geothermal water that is similar in isotope to the geothermal water of Nigorikawa production well, which indicated a tight relation in the origin with the group of Kaminoyu hot spring. (NEDO)

Outline of multipurpose utilization of geothermal resources in China

Energy Technology Data Exchange (ETDEWEB)

Huang, S.Y.; Wang, J.Y.; Wang, J.; Huang, G.S.

1980-09-01

China is rich in geothermal resources. The lower temperature limit of geothermal waters in China is defined as 25/sup 0/C. The thermal waters are categorized into three groups: low (25/sup 0/ to 60/sup 0/C), medium (60/sup 0/ to 100/sup 0/C) and high (> 100/sup 0/C) temperature thermal water. Xizang (Tibet), Taiwan and Yunnan are the most promising regions for the development of high temperature geothermal energy. Medium-low temperature water is more efficient for direct use. Since 1977, six experimental geothermal power stations have been set up throughout the country. In Beijing (Peking), Tianjin and other places thermal water has been used for space heating, industrial processing, agriculture, horticulture, and therapeutic sanatoriums, etc.

Bibliographical review about Na/Li geo-thermometry and lithium isotopes applied to worldwide geothermal waters. Final report

International Nuclear Information System (INIS)

Sanjuan, B.; Millot, R.

2009-09-01

This study is performed within the framework of the FP6 European project HITI (High Temperature Instruments for supercritical geothermal reservoir characterization and exploitation). This research project, co-funded by EU and the different partners, aims to provide geophysical and geochemical sensors and methods to evaluate deep geothermal wells up to supercritical conditions (T > 370 deg. C), which are more cost-effective than those of the conventional wells. A deep geothermal well is currently being drilled for this purpose into the Krafla area, Iceland, as part of the IDDP ('Iceland Deep Drilling Project') and with joint funding from Icelandic industry and science Institutes. Another deep well will be drilled in the Reykjanes peninsula, Iceland, within the framework of the same project. This study, a bibliographical review about the Na/Li geo-thermometer and lithium isotopes applied on the world geothermal waters, is the first step of the task envisaged by BRGM to use and validate the sodium-lithium (Na-Li) chemical geo-thermometer on Icelandic geothermal waters at temperatures ranging from 25 to 500 deg. C. In this study, more than 120 temperature and chemical data from world geothermal and oil-fields, sedimentary basins, oceanic ridges, emerged rifts and island arcs have been collected and investigated. These additional data have allowed to confirm and refine the three existing Na/Li thermometric relationships. Moreover, a new Na/Li thermometric relationship relative to the processes of seawater or dilute seawater-basalt interaction occurring in the oceanic ridges and emerged rifts is proposed. Even if the running of Na/Li is still poorly understood, the existence of a new thermometric relationship confirms that the Na/Li ratios not only depend on the temperature but also on other parameters such as the fluid salinity and origin, or the nature of the reservoir rocks in contact with the geothermal fluids. For most of the geothermal waters in contact with

Possibilities for the efficient utilisation of spent geothermal waters.

Science.gov (United States)

Tomaszewska, Barbara; Szczepański, Andrzej

2014-10-01

Waters located at greater depths usually exhibit high mineral content, which necessitates the use of closed systems, i.e. re-injecting them into the formation after recovering the heat. This significantly reduces investment efficiency owing to the need to drill absorption wells and to perform anti-corrosion and anti-clogging procedures. In this paper, possibilities for the efficient utilisation of cooled geothermal waters are considered, particularly with respect to open or mixed geothermal water installations. Where cooled water desalination technologies are used, this allows the water to be demineralised and used to meet local needs (as drinking water and for leisure purposes). The retentate left as a by-product of the process contains valuable ingredients that can be used for balneological and/or leisure purposes. Thus, the technology for desalinating spent geothermal waters with high mineral content allows improved water management on a local scale and makes it possible to minimise the environmental threat resulting from the need to dump these waters into waterways or surface water bodies and/or inject them into the formation. The paper is concerned with Polish geothermal system and provides information about the parameters of Polish geothermal waters.

Geothermal waters from the Taupo Volcanic Zone, New Zealand: Li, B and Sr isotopes characterization

International Nuclear Information System (INIS)

Millot, Romain; Hegan, Aimee; Négrel, Philippe

2012-01-01

Chemical and isotopic data for 23 geothermal water samples collected in New Zealand within the Taupo Volcanic Zone (TVZ) are reported. Major and trace elements including Li, B and Sr and their isotopic compositions (δ 7 Li, δ 11 B, 87 Sr/ 86 Sr) were determined in high temperature geothermal waters collected from deep boreholes in different geothermal fields (Ohaaki, Wairakei, Mokai, Kawerau and Rotokawa geothermal systems). Lithium concentrations are high (from 4.5 to 19.9 mg/L) and Li isotopic compositions (δ 7 Li) are homogeneous, ranging between −0.5‰ and +1.4‰. In particular, it is noteworthy that, except for the samples from the Kawerau geothermal field having slightly higher δ 7 Li values (+1.4%), the other geothermal waters have a near constant δ 7 Li signature around a mean value of 0‰ ± 0.6 (2σ, n = 21). Boron concentrations are also high and relatively homogeneous for the geothermal samples, falling between 17.5 and 82.1 mg/L. Boron isotopic compositions (δ 11 B) are all negative, and display a range between −6.7‰ and −1.9‰. These B isotope compositions are in agreement with those of the Ngawha geothermal field in New Zealand. Lithium and B isotope signatures are in a good agreement with a fluid signature mainly derived from water/rock interaction involving magmatic rocks with no evidence of seawater input. On the other hand, Sr concentrations are lower and more heterogeneous and fall between 2 and 165 μg/L. The 87 Sr/ 86 Sr ratios range from 0.70549 to 0.70961. These Sr isotope compositions overlap those of the Rotorua geothermal field in New Zealand, confirming that some geothermal waters (with more radiogenic Sr) have interacted with bedrocks from the metasedimentary basement. Each of these isotope systems on their own reveals important information about particular aspects of either water source or water/rock interaction processes, but, considered together, provide a more integrated understanding of the geothermal systems from

Equivalent Circulation Density Analysis of Geothermal Well by Coupling Temperature

Directory of Open Access Journals (Sweden)

Xiuhua Zheng

2017-02-01

Full Text Available The accurate control of the wellbore pressure not only prevents lost circulation/blowout and fracturing formation by managing the density of the drilling fluid, but also improves productivity by mitigating reservoir damage. Calculating the geothermal pressure of a geothermal well by constant parameters would easily bring big errors, as the changes of physical, rheological and thermal properties of drilling fluids with temperature are neglected. This paper researched the wellbore pressure coupling by calculating the temperature distribution with the existing model, fitting the rule of density of the drilling fluid with the temperature and establishing mathematical models to simulate the wellbore pressures, which are expressed as the variation of Equivalent Circulating Density (ECD under different conditions. With this method, the temperature and ECDs in the wellbore of the first medium-deep geothermal well, ZK212 Yangyi Geothermal Field in Tibet, were determined, and the sensitivity analysis was simulated by assumed parameters, i.e., the circulating time, flow rate, geothermal gradient, diameters of the wellbore, rheological models and regimes. The results indicated that the geothermal gradient and flow rate were the most influential parameters on the temperature and ECD distribution, and additives added in the drilling fluid should be added carefully as they change the properties of the drilling fluid and induce the redistribution of temperature. To ensure the safe drilling and velocity of pipes tripping into the hole, the depth and diameter of the wellbore are considered to control the surge pressure.

Temperature-induced impacts on groundwater quality and arsenic mobility in anoxic aquifer sediments used for both drinking water and shallow geothermal energy production.

Science.gov (United States)

Bonte, Matthijs; van Breukelen, Boris M; Stuyfzand, Pieter J

2013-09-15

Aquifers used for the production of drinking water are increasingly being used for the generation of shallow geothermal energy. This causes temperature perturbations far beyond the natural variations in aquifers and the effects of these temperature variations on groundwater quality, in particular trace elements, have not been investigated. Here, we report the results of column experiments to assess the impacts of temperature variations (5°C, 11°C, 25°C and 60°C) on groundwater quality in anoxic reactive unconsolidated sandy sediments derived from an aquifer system widely used for drinking water production in the Netherlands. Our results showed that at 5 °C no effects on water quality were observed compared to the reference of 11°C (in situ temperature). At 25°C, As concentrations were significantly increased and at 60 °C, significant increases were observed pH and DOC, P, K, Si, As, Mo, V, B, and F concentrations. These elements should therefore be considered for water quality monitoring programs of shallow geothermal energy projects. No consistent temperature effects were observed on Na, Ca, Mg, Sr, Fe, Mn, Al, Ba, Co, Cu, Ni, Pb, Zn, Eu, Ho, Sb, Sc, Yb, Ga, La, and Th concentrations, all of which were present in the sediment. The temperature-induced chemical effects were probably caused by (incongruent) dissolution of silicate minerals (K and Si), desorption from, and potentially reductive dissolution of, iron oxides (As, B, Mo, V, and possibly P and DOC), and mineralisation of sedimentary organic matter (DOC and P). Copyright © 2013 Elsevier Ltd. All rights reserved.

2014 Low-Temperature and Coproduced Geothermal Resources Fact Sheet

Energy Technology Data Exchange (ETDEWEB)

Tim Reinhardt, Program Manager

2014-09-01

As a growing sector of geothermal energy development, the Low-Temperature Program supports innovative technologies that enable electricity production and cascaded uses from geothermal resources below 300° Fahrenheit.

Isotope and chemical investigation of geothermal springs and thermal water produced by oil wells in potwat area, Pakistan

International Nuclear Information System (INIS)

Ahmad, M.; Rafique, M.; Tariq, J.A; Choudhry, M.A.; Hussain, Q.M.

2008-10-01

Isotopes and geochemical techniques were applied to investigate the origin, subsurface history and reservoir temperatures of geothermal springs in Potwar. Two sets of water samples were collected. Surface temperatures of geothermal springs ranges from 52 to 68.3 C. Waters produced by oil wells in Potwar area were also investigated. Geothermal springs of Potwar area are Na-HCO/sub 3/ type, while the waters produced by oil wells are Na-Cl and Ca-Cl types. Source of both the categories of water is meteoric water recharged from the outcrops of the formations in the Himalayan foothills. These waters undergo very high /sup 18/O-shift (up to 18%) due to rock-water interaction at higher temperatures. High salinity of the oil field waters is due to dissolution of marine evaporites. Reservoir temperatures of thermal springs determined by the Na-K geo thermometers are in the range of 56-91 deg. C, while Na-K-Ca, Na-K-Mg, Na-K-Ca-Mg and quartz geo thermometers give higher temperatures up to 177 C. Reservoir temperature determined by /sup 18/O(SO/Sub 4/-H/sub 2/O) geo thermometer ranges from 112 to 138 deg. C. There is wide variation in reservoir temperatures (54-297 deg. C) of oil fields estimated by different chemical geo thermometers. Na-K geo thermometer seems more reliable which gives close estimates to real temperature (about 100 deg. C) determined during drilling of oil wells. (author)

Potential effects of the Hawaii geothermal project on ground-water resources on the Island of Hawaii

Energy Technology Data Exchange (ETDEWEB)

Sorey, M.L.; Colvard, E.M.

1994-07-01

This report provides data and information on the quantity and quality of ground-water resources in and adjacent to proposed geothermal development areas on the Island of Hawaii Geothermal project for the development of as much as 500 MW of electric power from the geothermal system in the East Rift Zone of Kilauea Volcano. Data presented for about 31 wells and 8 springs describe the chemical, thermal, and hydraulic properties of the ground-water system in and adjacent to the East Rift Zone. On the basis of this information, potential effects of this geothermal development on drawdown of ground-water levels and contamination of ground-water resources are discussed. Significant differences in ground-water levels and in the salinity and temperature of ground water within the study area appear to be related to mixing of waters from different sources and varying degrees of ground-water impoundment by volcanic dikes. Near Pahoa and to the east, the ground-water system within the rift is highly transmissive and receives abundant recharge from precipitation; therefore, the relatively modest requirements for fresh water to support geothermal development in that part of the east rift zone would result in minimal effects on ground-water levels in and adjacent to the rift. To the southwest of Pahoa, dike impoundment reduces the transmissivity of the ground-water system to such an extent that wells might not be capable of supplying fresh water at rates sufficient to support geothermal operations. Water would have to be transported to such developments from supply systems located outside the rift or farther downrift. Contaminant migration resulting from well accidents could be rapid because of relatively high ground-water velocities in parts of the region. Hydrologic monitoring of observation wells needs to be continued throughout development of geothermal resources for the Hawaii Geothermal Project to enable the early detection of leakage and migration of geothermal fluids.

The influence of heat sink temperature on the seasonal efficiency of shallow geothermal heat pumps

Science.gov (United States)

Pełka, Grzegorz; Luboń, Wojciech; Sowiżdżał, Anna; Malik, Daniel

2017-11-01

Geothermal heat pumps, also known as ground source heat pumps (GSHP), are the most efficient heating and cooling technology utilized nowadays. In the AGH-UST Educational and Research Laboratory of Renewable Energy Sources and Energy Saving in Miękinia, shallow geothermal heat is utilized for heating. In the article, the seasonal efficiency of two geothermal heat pump systems are described during the 2014/2015 heating season, defined as the period between 1st October 2014 and 30th April 2015. The first system has 10.9 kW heating capacity (according to European Standard EN 14511 B0W35) and extracts heat from three vertical geothermal loops at a depth of 80m each. During the heating season, tests warmed up the buffer to 40°C. The second system has a 17.03 kW heating capacity and extracts heat from three vertical geothermal loops at a depth of 100 m each, and the temperature of the buffer was 50°C. During the entire heating season, the water temperatures of the buffers was constant. Seasonal performance factors were calculated, defined as the quotient of heat delivered by a heat pump to the system and the sum of electricity consumed by the compressor, source pump, sink pump and controller of heat pumps. The measurements and calculations give the following results: - The first system was supplied with 13 857 kWh/a of heat and consumed 3 388 kWh/a electricity. The SPF was 4.09 and the average temperature of outlet water from heat pump was 40.8°C, and the average temperature of brine flows into the evaporator was 3.7 °C; - The second system was supplied with 12 545 kWh/a of heat and consumed 3 874 kWh/a electricity. The SPF was 3.24 and the average temperature of outlet water from heat pump was 51.6°C, and the average temperature of brine flows into the evaporator was 5.3°C. To summarize, the data shown above presents the real SPF of the two systems. It will be significant in helping to predict the SPF of objects which will be equipped with ground source heat pumps.

Subsurface temperatures and geothermal gradients on the north slope of Alaska

Science.gov (United States)

Collett, T.S.; Bird, K.J.; Magoon, L.B.

1993-01-01

On the North Slope of Alaska, geothermal gradient data are available from high-resolution, equilibrated well-bore surveys and from estimates based on well-log identification of the base of ice-bearing permafrost. A total of 46 North Slope wells, considered to be in or near thermal equilibrium, have been surveyed with high-resolution temperatures devices and geothermal gradients can be interpreted directly from these recorded temperature profiles. To augment the limited North Slope temperature data base, a new method of evaluating local geothermal gradients has been developed. In this method, a series of well-log picks for the base of the ice-bearing permafrost from 102 wells have been used, along with regional temperature constants derived from the high-resolution stabilized well-bore temperature surveys, to project geothermal gradients. Geothermal gradients calculated from the high-resolution temperature surveys generally agree with those projected from known ice-bearing permafrost depths over most of the North Slope. Values in the ice-bearing permafrost range from ??? 1.5??C 100 m in the Prudhoe Bay area to ??? 4.5??C 100 m in the east-central portion of the National Petroleum Reserve in Alaska. Geothermal gradients below the ice-bearing permafrost sequence range from ??? 1.6??C 100 m to ??? 5.2??C 100 m. ?? 1993.

Geothermal heat pumps - Trends and comparisons

Energy Technology Data Exchange (ETDEWEB)

Lund, John W

1989-01-01

Heat pumps are used where geothermal water or ground temperatures are only slightly above normal, generally 50 to 90 deg. F. Conventional geothermal heating (and cooling) systems are not economically efficient at these temperatures. Heat pumps, at these temperatures, can provide space heating and cooling, and with a desuperheater, domestic hot water. Two basic heat pump systems are available, air-source and water- or ground-source. Water- and ground-coupled heat pumps, referred to as geothermal heat pumps (GHP), have several advantages over air-source heat pumps. These are: (1) they consume about 33% less annual energy, (2) they tap the earth or groundwater, a more stable energy source than air, (3) they do not require supplemental heat during extreme high or low outside temperatures, (4) they use less refrigerant (freon), and (5) they have a simpler design and consequently less maintenance.

Cancer mortality and other causes of death in users of geothermal hot water.

Science.gov (United States)

Kristbjornsdottir, Adalbjorg; Rafnsson, Vilhjalmur

2015-01-01

Residents of geothermal areas have increased incidence of non-Hodgkin's lymphoma, breast, prostate, and kidney cancers. The aim was to study whether this is also reflected in cancer mortality among the population using geothermal hot water for space heating, washing, and showering. The follow-up was from 1981 to 2009. Personal identifier of those 5-64 years of age was used in record linkage with nationwide death registry. Thus, vital and emigration status was ascertained. The exposed population was defined as inhabitants of communities with district heating generated from geothermal wells since 1972. Reference populations were inhabitants of other areas with different degrees of volcanic/geothermal activity. Hazard ratio (HR) and 95% confidence intervals (CI) were adjusted for age, gender, education, housing, reproductive factors and smoking habits. Among those using geothermal water, the HR for all causes of death was 0.98 (95% CI 0.91-1.05) as compared with cold reference area. The HR for breast cancer was 1.53 (1.04-2.24), prostate cancer 1.74 (1.21-2.52), kidney cancer 1.78 (1.03-3.07), and for non-Hodgkin's lymphoma 2.01 (1.05-3.38). HR for influenza was 3.36 (1.32-8.58) and for suicide 1.49 (1.03-2.17). The significant excess mortality risk of breast and prostate cancers, and non-Hodgkin's lymphoma confirmed the results of similarly designed studies in Iceland on cancer incidence among populations from high-temperature geothermal areas and users of geothermal hot water. The risk is not confined to cancers with good prognosis, but also concerns fatal cancers. Further studies are needed on the chemical and physical content of the water and the environment emissions in geothermal areas.

Performance analysis of low temperature heat source of organic Rankine cycle for geothermal application

Science.gov (United States)

Pintoro, A.; Ambarita, H.; Nur, T. B.; Napitupulu, F. H.

2018-02-01

Indonesia has a high potential energy resources from geothermal activities. Base on the report of Asian Development Bank and World Bank, the estimated of Indonesian hydrothermal geothermal resource considered to be the largest among the world. If it’s can be utilized to produce the electric power, it’s can contribute to increasing the electrification rates in Indonesia. In this study, an experimental studied of electric power generation, utilizing the Organic Rankine Cycle (ORC) system to convert the low level heat of hydrothermal as an energy source. The temperature of hydrothermal was modelled as hot water from water boiler which has a temperature range from 60 °C - 100 °C to heat up the organic working fluid of ORC system. The system can generated 1,337.7 watts of electricity when operated using R134A with hot water inlet temperature of 100 °C. Changing system working fluid to R245fa, the net power obtained increase to 1,908.9 watts with the same heat source condition. This study showed that the ORC system can be implemented to utilize low temperature heat source of hydrothermal in Indonesia.

Advanced Low Temperature Geothermal Power Cycles (The ENTIV Organic Project) Final Report

Energy Technology Data Exchange (ETDEWEB)

Mugerwa, Michael [Technip USA, Inc., Claremont, CA (United States)

2015-11-18

Feasibility study of advanced low temperature thermal power cycles for the Entiv Organic Project. Study evaluates amonia-water mixed working fluid energy conversion processes developed and licensed under Kalex in comparison with Kalina cycles. Both cycles are developed using low temperature thermal resource from the Lower Klamath Lake Geothermal Area. An economic feasibility evaluation was conducted for a pilot plant which was deemed unfeasible by the Project Sponsor (Entiv).

Hydrogeochemical characteristics and genesis of the high-temperature geothermal system in the Tashkorgan basin of the Pamir syntax, western China

Science.gov (United States)

Li, Yiman; Pang, Zhonghe; Yang, Fengtian; Yuan, Lijuan; Tang, Pinghui

2017-11-01

High-temperature geothermal systems in China, such as those found in Tenchong and Tibet, are common. A similar system without obvious manifestations found in the Tashkorgan basin in the western Xinjiang Autonomous Region, however, was not expected. The results from borehole measurements and predictions with geothermometers, such as quartz, Na-K and Na-K-Mg, indicate that the reservoir temperature is approximately 250-260 °C. Geothermal water is high in Total Dissolved Solids (>2.5 g/L) and SiO2 content (>273 mg/L), and the water type is Cl·SO4-Na, likely resulting from water-rock interactions in the granodiorite reservoirs. Based on isotope analysis, it appears to be recharged by local precipitation and river water. Evidence from the relationships between major ions and the Cl and molar Na/Cl ratio suggests mixing between deep geothermal water and shallow cold groundwater during the upwelling process. Mixing ratios calculated by the relationship between Cl and SiO2 show that the proportion from cold end-members are 96-99% and 40-90% for riparian zone springs and geothermal water from boreholes, respectively. Active regional tectonic and Neo-tectonic movements in the Pamir syntax as well as radioactive elements in the granodiorite reservoir of the Himalayan stage provide basis for the high heat flow background (150-350 mW/m2). NNW trending fault systems intersecting with overlying NE faults provide circulation conduits with high permeability for geothermal water.

INTEGRATED EXPLORATION OF GEOTHERMAL RESOURCES

Directory of Open Access Journals (Sweden)

A. B. Alkhasov

2016-01-01

Full Text Available The aim. The aim is to develop the energy efficient technologies to explore hydro geothermal resources of different energy potential.Methods. Evaluation of the effectiveness of the proposed technologies has been carried out with the use of physical and mathematical, thermodynamic and optimization methods of calculation and the physical and chemical experimental research.Results. We propose the technology of integrated exploration of low-grade geothermal resources with the application of heat and water resource potential on various purposes. We also argue for the possibility of effective exploration of geothermal resources by building a binary geothermal power plant using idle oil and gas wells. We prove the prospect of geothermal steam and gas technologies enabling highly efficient use of thermal water of low energy potential (80 - 100 ° C degrees to generate electricity; the prospects of complex processing of high-temperature geothermal brine of Tarumovsky field. Thermal energy is utilized in a binary geothermal power plant in the supercritical Rankine cycle operating with a low-boiling agent. The low temperature spent brine from the geothermal power plant with is supplied to the chemical plant, where the main chemical components are extracted - lithium carbonate, magnesium burning, calcium carbonate and sodium chloride. Next, the waste water is used for various water management objectives. Electricity generated in the binary geothermal power plant is used for the extraction of chemical components.Conclusions. Implementation of the proposed technologies will facilitate the most efficient development of hydro geothermal resources of the North Caucasus region. Integrated exploration of the Tarumovsky field resources will fully meet Russian demand for lithium carbonate and sodium chloride.

State-coupled low-temperature geothermal-resource assessment program, Fiscal Year 1979. Final technical report

Energy Technology Data Exchange (ETDEWEB)

Icerman, L.; Starkey, A.; Trentman, N. (eds.)

1980-10-01

The results of low-temperature geothermal energy resource assessment efforts in New Mexico during the period from 1 October 1978 to 30 June 1980 are summarized. The results of the efforts to extend the inventory of geothermal energy resources in New Mexico to low-temperature geothermal reservoirs with the potential for direct heating applications are given. These efforts focused on compiling basic geothermal data and new hydrology and temperature gradient data throughout New Mexico in a format suitable for direct transfer to the US Geological Survey and the National Oceanic and Atmospheric Administration for inclusion in the GEOTHERM data file and for preparation of New Mexico low-temperature geothermal resources maps. The results of geothermal reservoir confirmation studies are presented. (MHR)

Temperature logging of groundwater in bedrock wells for geothermal gradient characterization in New Hampshire, 2012

Science.gov (United States)

Degnan, James; Barker, Gregory; Olson, Neil; Wilder, Leland

2012-01-01

The U.S. Geological Survey, in cooperation with the New Hampshire Geological Survey, measured the fluid temperature of groundwater in deep bedrock wells in the State of New Hampshire in order to characterize geothermal gradients in bedrock. All wells selected for the study had low water yields, which correspond to low groundwater flow from fractures. This reduced the potential for flow-induced temperature changes that would mask the natural geothermal gradient in the bedrock. All the wells included in this study were privately owned, and permission to use the wells was obtained from homeowners before logging.

Geothermal studies in China

Science.gov (United States)

Ji-Yang, Wang; Mo-Xiang, Chen; Ji-An, Wang; Xiao, Deng; Jun, Wang; Hsien-Chieh, Shen; Liang-Ping, Hsiung; Shu-Zhen, Yan; Zhi-Cheng, Fan; Xiu-Wen, Liu; Ge-Shan, Huang; Wen-Ren, Zhang; Hai-Hui, Shao; Rong-Yan, Zhang

1981-01-01

Geothermal studies have been conducted in China continuously since the end of the 1950's with renewed activity since 1970. Three areas of research are defined: (1) fundamental theoretical research on geothermics, including subsurface temperatures, terrestrial heat flow and geothermal modeling; (2) exploration for geothermal resources and exploitation of geothermal energy; and (3) geothermal studies in mines. Regional geothermal studies have been conducted recently in North China and more than 2000 values of subsurface temperature have been obtained. Temperatures at a depth of 300 m generally range from 20 to 25°C with geothermal gradients from 20 to 40°C/km. These values are regarded as an average for the region with anomalies related to geological factors. To date, 22 reliable heat flow data from 17 sites have been obtained in North China and the data have been categorized according to fault block tectonics. The average heat flow value at 16 sites in the north is 1.3 HFU, varying from 0.7 to 1.8 HFU. It is apparent that the North China fault block is characterized by a relatively high heat flow with wide variations in magnitude compared to the mean value for similar tectonic units in other parts of the world. It is suggested that although the North China fault block can be traced back to the Archaean, the tectonic activity has been strengthening since the Mesozoic resulting in so-called "reactivation of platform" with large-scale faulting and magmatism. Geothermal resources in China are extensive; more than 2000 hot springs have been found and there are other manifestations including geysers, hydrothermal explosions, hydrothermal steam, fumaroles, high-temperature fountains, boiling springs, pools of boiling mud, etc. In addition, there are many Meso-Cenozoic sedimentary basins with widespread aquifers containing geothermal water resources in abundance. The extensive exploration and exploitation of these geothermal resources began early in the 1970's. Since then

Geothermic analysis of high temperature hydrothermal activities area in Western plateau of Sichuan province, China

Science.gov (United States)

Zhang, J.

2016-12-01

There is a high temperature hydrothermal activity area in the western plateau of Sichuan. More than 200 hot springs points have been found in the region, including 11 hot spring water temperature above local boiling point. Most of these distribute along Jinshajjiang fracture, Dege-Xiangcheng fracture, Ganzi-Litang fracture as well as Xianshuihe fracture, and form three high-temperature hydrothermal activity strips in the NW-SE direction. Using gravity, magnetic, seismic and helium isotope data, this paper analyzed the crust-mantle heat flow structure, crustal heat source distribution and water heating system. The results show that the geothermal activity mainly controlled by the "hot" crust. The ratio of crustal heat flow and surface heat flow is higher than 60%. In the high temperature hydrothermal activities area, there is lower S wave velocity zone with VsGeothermal water mainly reserve in the Triassic strata of the containing water good carbonate rocks, and in the intrusive granite which is along the fault zone. The thermal energy of Surface heat thermal activities mainly comes from the high-temperature hot source which is located in the middle and lower crust. Being in the deep crustal fracture, the groundwater infiltrated to the deep crust and absorbed heat, then, quickly got back to the surface and formed high hot springs.

Deep geothermal processes acting on faults and solid tides in coastal Xinzhou geothermal field, Guangdong, China

Science.gov (United States)

Lu, Guoping; Wang, Xiao; Li, Fusi; Xu, Fangyiming; Wang, Yanxin; Qi, Shihua; Yuen, David

2017-03-01

This paper investigated the deep fault thermal flow processes in the Xinzhou geothermal field in the Yangjiang region of Guangdong Province. Deep faults channel geothermal energy to the shallow ground, which makes it difficult to study due to the hidden nature. We conducted numerical experiments in order to investigate the physical states of the geothermal water inside the fault zone. We view the deep fault as a fast flow path for the thermal water from the deep crust driven up by the buoyancy. Temperature measurements at the springs or wells constrain the upper boundary, and the temperature inferred from the Currie temperature interface bounds the bottom. The deepened boundary allows the thermal reservoir to revolve rather than to be at a fixed temperature. The results detail the concept of a thermal reservoir in terms of its formation and heat distribution. The concept also reconciles the discrepancy in reservoir temperatures predicted from both quartz and Na-K-Mg. The downward displacement of the crust increases the pressure at the deep ground and leads to an elevated temperature and a lighter water density. Ultimately, our results are a first step in implementing numerical studies of deep faults through geothermal water flows; future works need to extend to cases of supercritical states. This approach is applicable to general deep-fault thermal flows and dissipation paths for the seismic energy from the deep crust.

Bibliographical review about Na/Li geo-thermometry and lithium isotopes applied to worldwide geothermal waters. Final report

Energy Technology Data Exchange (ETDEWEB)

Sanjuan, B.; Millot, R.

2009-09-15

This study is performed within the framework of the FP6 European project HITI (High Temperature Instruments for supercritical geothermal reservoir characterization and exploitation). This research project, co-funded by EU and the different partners, aims to provide geophysical and geochemical sensors and methods to evaluate deep geothermal wells up to supercritical conditions (T > 370 deg. C), which are more cost-effective than those of the conventional wells. A deep geothermal well is currently being drilled for this purpose into the Krafla area, Iceland, as part of the IDDP ('Iceland Deep Drilling Project') and with joint funding from Icelandic industry and science Institutes. Another deep well will be drilled in the Reykjanes peninsula, Iceland, within the framework of the same project. This study, a bibliographical review about the Na/Li geo-thermometer and lithium isotopes applied on the world geothermal waters, is the first step of the task envisaged by BRGM to use and validate the sodium-lithium (Na-Li) chemical geo-thermometer on Icelandic geothermal waters at temperatures ranging from 25 to 500 deg. C. In this study, more than 120 temperature and chemical data from world geothermal and oil-fields, sedimentary basins, oceanic ridges, emerged rifts and island arcs have been collected and investigated. These additional data have allowed to confirm and refine the three existing Na/Li thermometric relationships. Moreover, a new Na/Li thermometric relationship relative to the processes of seawater or dilute seawater-basalt interaction occurring in the oceanic ridges and emerged rifts is proposed. Even if the running of Na/Li is still poorly understood, the existence of a new thermometric relationship confirms that the Na/Li ratios not only depend on the temperature but also on other parameters such as the fluid salinity and origin, or the nature of the reservoir rocks in contact with the geothermal fluids. For most of the geothermal waters in contact

Geothermal rice drying unit in Kotchany, Macedonia

International Nuclear Information System (INIS)

Popovski, K.; Dimitrov, K.; Andrejevski, B.; Popovska, S.

1992-01-01

A geothermal field in Kotchany (Macedonia) has very advantageous characteristics for direct application purposes. Low content of minerals, moderate temperature (78C) and substantial available geothermal water flow (up to 300 1/s) enabled the establishment of a district heating scheme comprising mainly agricultural and industrial uses. A rice drying unit of 10 t/h capacity was installed 8 years ago, using the geothermal water as the primary heat source. A temperature drop of 75/50C enables the adaptation of conventional drying technology, already proven in practice in the surrounding rice growing region. Water to air heat exchanger and all necessary equipment and materials are of local production, made of copper and carbon steel. The use of such drying units is strongly recommended for the concrete district heating scheme because it offers a very simple geothermal application and enables improvement in the annual heating load factor without high investments in geothermal water distribution lines

DETERMINING UNDISTURBED GROUND TEMPERATURE AS PART OF SHALLOW GEOTHERMAL RESOURCES ASSESSMENT

Directory of Open Access Journals (Sweden)

Tomislav Kurevija

2010-12-01

Full Text Available The undisturbed ground temperature is one of the key thermogeological parameters for the assessment and utilization of shallow geothermal resources. Geothermal energy is the type of energy which is stored in the ground where solar radiation has no effect. The depth at which the undisturbed ground temperature occurs, independent of seasonal changes in the surface air temperature, is functionally determined by climate parameters and thermogeological properties. In deeper layers, the increase of ground temperature depends solely on geothermal gradient. Determining accurate values of undisturbed ground temperature and depth of occurrence is crucial for the correct sizing of a borehole heat exchanger as part of the ground-source heat pump system, which is considered the most efficient technology for utilising shallow geothermal resources. The purpose of this paper is to define three specific temperature regions, based on the measured ground temperature data collected from the main meteorological stations in Croatia. The three regions are: Northern Croatia, Adriatic region, and the regions of Lika and Gorski Kotar.

Geothermal development plan: Maricopa County

Energy Technology Data Exchange (ETDEWEB)

White, D.H.; Goldstone, L.A.

1982-08-01

The Maricopa County Geothermal Development Plan evaluated the market potential for utilizing geothermal energy. The study identified six potential geothermal resource areas with temperatures less than 100{sup 0}C (212{sup 0}F) and in addition, four suspected intermediate temperature areas (90{sup 0} to 150{sup 0}C, 194{sup 0} to 300{sup 0}F). Geothermal resources are found to occur in and near the Phoenix metropolitan area where average population growth rates of two to three percent per year are expected over the next 40 years. Rapid growth in the manufacturing, trade and service sectors of the regional economy provides opportunities for the direct utilization of geothermal energy. A regional energy use analysis is included containing energy use and price projections. Water supplies are found to be adequate to support this growth, though agricultural water use is expected to diminish. The study also contains a detailed section matching geothermal resources to potential users. Two comparative analyses providing economic details for space heating projects are incorporated.

Geochemistry of thermal/mineral waters in the Clear Lake region, California, and implications for hot dry rock geothermal development

Energy Technology Data Exchange (ETDEWEB)

Goff, F.; Adams, A.I.; Trujillo, P.E.; Counce, D.; Mansfield, J.

1993-02-01

Thermal/mineral waters of the Clear Lake region are broadly classified as thermal meteoric and connote types based on chemical and isotopic criteria. Ratios of conservative components such as B/Cl are extremely different among all thermal/mineral waters of the Clear Lake region except for clusters of waters emerging from specific areas such as the Wilbur Springs district and the Agricultural Park area south of Mt. Konocti. In contrast, ratios of conservative components in large, homogeneous geothermal reservoirs are constant. Stable isotope values of Clear Lake region waters show a mixing trend between thermal meteoric and connote end-members. The latter end-member has enriched [delta]D as well as enriched d[sup l8]O, very different from typical high-temperature geothermal reservoir waters. Tritium data and modeling of ages indicate most Clear Lake region waters are 500 to > 10,000 yr., although mixing of old and young components is implied by the data. The age of end-member connate water is probably > 10,000 yr. Subsurface equilibration temperature of most thermal/mineral waters of the Clear Lake region is [le] 150[degrees]C based on chemical geothermometers but it is recognized that Clear Lake region waters are not typical geothermal fluids and that they violate rules of application of many geothermometers. The combined data indicate that no large geothermal reservoir underlies the Clear Lake region and that small localized reservoirs have equilibration temperatures [le] 150[degrees]C (except for Sulphur Bank Mine). Hot dry rock technologies are the best way to commercially exploit the known high temperatures existing beneath the Clear Lake region, particularly within the main Clear Lake volcanic field.

Preliminary interpretation of isotopic studies of geothermal waters from the Beijing region (P.R. China)

International Nuclear Information System (INIS)

Keyan, Zheng; Da-Lei, Ma; Changfang, Xie; Shangyao, Huang; Jianghua, Feng; Jingshu, Wu

1982-01-01

Isotopic studies of thermal and cold surface waters sampled in Beijing region have shown that the thermal waters are meteoric waters which have been precipitated in the mountainous area lying to the NW of Beijing. ΔD and over distances of more than 150 km in Sinian basement rocks which are 3 to 5 km in the SE sector of the region. Significant 18 O exchange with basement rocks occurs in the Jizhong Depression about 60 km to the SE of Beijing. On a smaller scale, a SE flow of thermal waters in basement rocks in corroborated by Δ 34 S data for the Beijing area and the Beijing geothermal field. The Beijing geothermal field and other geothermal fields in the SE sector of the Beijing region are an example for low temperature systems where the heat is derived from a normal or slightly greater than normal, terrestrial heat flow

Design A Prototype of Temperature Logging Tools for Geothermal Prospecting Areas

Directory of Open Access Journals (Sweden)

Supriyanto

2013-08-01

Full Text Available The costs of geothermal exploration are very high because technology is still imported from other countries. The local business players in the geothermal sector do not have the ability to compete with global companies. To reduce costs, we need to develop our own equipment with competitive prices. Here in Indonesia, we have started to design a prototype of temperature logging tools for geothermal prospecting areas. This equipment can be used to detect temperature versus depth variations. To measure the thermal gradient, the platinum resistor temperature sensor is moved slowly down along the borehole. The displacement along the borehole is measured by a rotary encoder. This system is controlled by a 16-bit H8/3069F microcontroller. The acquired temperature data is displayed on a PC monitor using a Python Graphical User Interface. The system has been already tested in the Gunung Pancar geothermal prospect area in Bogor.

Geothermal energy

Directory of Open Access Journals (Sweden)

Manzella A.

2015-01-01

Full Text Available Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG emissions. Geothermal energy is stored in rocks and in fluids circulating in the underground. Electricity generation usually requires geothermal resources temperatures of over 100°C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology, spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Geothermal technology, which has focused so far on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth’s crust.

Optimization of the exploitation system of a low enthalpy geothermal aquifer with zones of different transmissivities and temperatures

International Nuclear Information System (INIS)

Tselepidou, K.; Katsifarakis, K.L.

2010-01-01

Market penetration of renewable energy sources, such as geothermal energy, could be promoted even by small cost reductions, achieved through improved development design. This paper deals with optimization of the exploitation system of a low enthalpy geothermal aquifer, by means of the method of genetic algorithms, which has been successfully used in similar problems of groundwater resources management. With respect to water flow, the aquifer consists of two zones of different transmissivities, while from the thermal point of view it may bear any number of zones with different temperatures. The optimization process comprises the annual pumping cost of the required flow and the amortization cost of the pipe network, which carries the hot water from the wells to a central water tank, situated at the border of the geothermal field. Results show that application of the proposed methodology allows better planning of low enthalpy geothermal heating systems, which may be crucial in cases of marginal financial viability. (author)

Companion Study Guide to Short Course on Geothermal Corrosion and Mitigation in Low Temperature Geothermal Heating Systems

Energy Technology Data Exchange (ETDEWEB)

Ellis, II, P F

1985-04-24

The economic utilization of geothermal resources with temperatures less than 220 degrees Fahrenheit for purposes other than electric power generation (direct utilization) requires creation of systems with long plant life and minimum operation and maintenance costs. Development of such systems requires careful corrosion engineering if the most cost effective material selections and design choices are to be made. This study guide presents guidelines for materials selection for low-temperature geothermal systems (120 - 200 degrees Fahrenheit), as well as guidance in materials design of heat pump systems for very-lowtemperature geothermal resources (less than 120 degrees Fahrenheit). This guideline is divided into five sections and an Appendix.

Control methodologies based on geothermal recirculating aquaculture system

International Nuclear Information System (INIS)

Farghally, Hanaa M.; Atia, Doaa M.; El-madany, Hanaa T.; Fahmy, Faten H.

2014-01-01

One of the most common uses of geothermal heat is in RAS (recirculation aquaculture systems) where the water temperature is accurately controlled for optimum growing conditions for sustainable and intensive rearing of marine and freshwater fish. This paper presents a design for RAS rearing tank and plate type heat exchanger to be used with geothermal energy as a source of heating water. A well at Umm Huweitat on the Red Sea is used as a source of geothermal energy. The heat losses from the RAS tank are calculated using Geo Heat Center Software. Then a plate type heat exchanger is designed using the epsilon–NTU (number of transfer units) analysis method. For optimal growth and abundance of production, a different techniques of control system are applied to control the water temperature. The total system is built in MATLAB/SIMULINK to study the overall performance of control unit. Finally, a comparison between PI, Fuzzy-PID, and Fuzzy Logic Control has been done. - Highlights: • Design recirculating aquaculture system using geothermal energy. • Design a PI controller for water temperature control. • Design a Fuzzy logic controller for water temperature control. • Design a Fuzzy-PID controller for water temperature control. • Comparison between different control systems

The Hydrogeochemistry of Qingshui Geothermal Field, Northeastern Taiwan.

Science.gov (United States)

Yu-Wen, Chen; Cheng-Kuo, Lin; Wayne, Lin; Yu-Te, Chang; Pei-Shan, Hsieh

2015-04-01

The Qingshui geothermal field is located at the upstream valley of Lanyang Creek, northeastern Taiwan. It is renowned as a geothermal field. The previous studies demonstrated a higher geothermal gradient, 100oC/km warmer than a normal geotherm. However, Qingshui geothermal field has not been well developed due to the higher mining costs. In the recent years, the Taiwan government has been focusing on developing alternative and renewable energy and initiated a 10 year project, Nation Energy Program. This study is part of this project In general, it is very difficult to collect deep downhole samples without considerable change of hydro- and gas- chemistry of water under high temperature and pressure. A new sampling tool, GTF Sampler, was designed by the research team, Green Energy and Environment Laboratories, Industrial Technology Research Institute. This tool can simultaneously collect high quality geothermal water and gas sample and moreover, the sampling depth can reach up to 800 meters. Accordingly, a more accurate measurements can be conducted in the laboratory. In this study, 10 geothermal samples were collected and measured. The results demonstrate that geothermal water samples are characterized with Na(K)-HCO3 water type and located at the mature water area in Giggenbach Na-K-Mg diagram. Several geothermometers, including silica and cation geothermometry, were used to estimate potential temperature in the geothermal reservoir systems. In general, the geothermoters of Na-K and Na-K-Ca obtain reservoir temperatures between 120-190oC and 130-210oC, respectively, but the silica geothermometer indicates a lower reservoir temperature between 90 and 170oC. There is no big difference among them. It is worth to note that all calculated temperatures are lower than those of in-situ downhole measurements; therefore, more detailed and advanced researches would be needed for the inconsistency. To examine the argument about igneous heat source in the previous studies, rare

The effect of silica in washing with geothermal water, Iceland

International Nuclear Information System (INIS)

Lindal, B.

1992-01-01

Industrial washing operation using geothermal water in Iceland are reported and testing designed to explain the beneficial effect of geothermal water for washing described. The findings indicate, that the silica content of the water may be the principal component for a superior washing quality

Geothermal energy

Directory of Open Access Journals (Sweden)

Manzella A.

2017-01-01

Full Text Available Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG emissions. Geothermal energy is the thermal energy stored in the underground, including any contained fluid, which is available for extraction and conversion into energy products. Electricity generation, which nowadays produces 73.7 TWh (12.7 GW of capacity worldwide, usually requires geothermal resources temperatures of over 100 °C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology, spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Produced geothermal heat in the world accounts to 164.6 TWh, with a capacity of 70.9 GW. Geothermal technology, which has focused for decades on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth’s crust.

Geothermal energy

Science.gov (United States)

Manzella, A.

2017-07-01

Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG) emissions. Geothermal energy is the thermal energy stored in the underground, including any contained fluid, which is available for extraction and conversion into energy products. Electricity generation, which nowadays produces 73.7 TWh (12.7 GW of capacity) worldwide, usually requires geothermal resources temperatures of over 100 °C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology), spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Produced geothermal heat in the world accounts to 164.6 TWh, with a capacity of 70.9 GW. Geothermal technology, which has focused for decades on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth's crust.

Prospects of development of highly mineralized high-temperature resources of the Tarumovskoye geothermal field

Science.gov (United States)

Alkhasov, A. B.; Alkhasova, D. A.; Ramazanov, A. Sh.; Kasparova, M. A.

2016-06-01

The promising nature of integrated processing of high-temperature geothermal brines of the Tarumovskoye geothermal field is shown. Thermal energy of a geothermal brine can be converted to the electric power at a binary geothermal power plant (GPP) based on low-boiling working substance. The thermodynamic Rankine cycles are considered which are implemented in the GPP secondary loop at different evaporation temperatures of the working substance―isobutane. Among them, the most efficient cycle from the standpoint of attaining a maximum power is the supercritical one which is close to the so-called triangular cycle with an evaporation pressure of p e = 5.0 MPa. The used low-temperature brine is supplied from the GPP to a chemical plant, where main chemical components (lithium carbonate, burnt magnesia, calcium carbonate, and sodium chloride) are extracted from it according to the developed technology of comprehensive utilization of geothermal brines of chloride-sodium type. The waste water is delivered to the geotechnological complex and other consumers. For producing valuable inorganic materials, the electric power generated at the GPP is used. Owing to this, the total self-sufficiency of production and independence from external conditions is achieved. The advantages of the proposed geotechnological complex are the full utilization of the heat potential and the extraction of main chemical components of multiparameter geothermal resources. In this case, there is no need for reverse pumping, which eliminates the significant capital costs for building injection wells and a pumping station and the operating costs for their service. A characteristic of the modern state of the field and estimated figures of the integrated processing of high-temperature brines of well no. 6 are given, from which it follows that the proposed technology has a high efficiency. The comprehensive development of the field resources will make it possible to improve the economic structure of the

Water Desalination using geothermal energy

KAUST Repository

Goosen, M.; Mahmoudi, H.; Ghaffour, NorEddine

2010-01-01

The paper provides a critical overview of water desalination using geothermal resources. Specific case studies are presented, as well as an assessment of environmental risks and market potential and barriers to growth. The availability

Trace element hydrochemistry indicating water contamination in and around the Yangbajing geothermal field, Tibet, China.

Science.gov (United States)

Guo, Qinghai; Wang, Yanxin

2009-10-01

Thirty-eight water samples were collected at Yangbajing to investigate the water contamination resulting from natural geothermal water discharge and anthropogenic geothermal wastewater drainage. The results indicate that snow or snow melting waters, Yangbajing River waters and cold groundwaters are free from geothermal water-related contamination, whereas Zangbo river waters are contaminated by geothermal wastewaters. Moreover, there may exist geothermal springs under the riverbed of a tributary stream of Zangbo River as shown by its Cd, Li, Mo and Pb concentrations. The efforts made in this study show trace element hydrochemistry can well indicate water quality degradation related to geothermal water exploitation.

An innovative ORC power plant layout for heat and power generation from medium- to low-temperature geothermal resources

International Nuclear Information System (INIS)

Fiaschi, Daniele; Lifshitz, Adi; Manfrida, Giampaolo; Tempesti, Duccio

2014-01-01

Highlights: • Explotation of medium temperature geothermal resource with ORC–CHP is investigated. • A new CHP configuration to provide higher temperature to thermal user is proposed. • Several organic fluids and wide range of heat demand are studied. • The system produces higher power (almost 55%) in comparison to typical layouts. • Optimal working fluids vary with the characteristics of the heat demand. - Abstract: Medium temperature (up to 170 °C), water dominated geothermal resources are the most widespread in the world. The binary geothermal-ORC power plants are the most suitable energy conversion systems for this kind of resource. Specifically, combined heat and power (CHP) systems have the potential to improve the efficiency in exploiting the geothermal resources by cascading the geothermal fluid heat carrier to successively lower temperature users, thus increasing first and second law efficiency of the entire power plant. However, geothermal CHPs usually extract heat from the geofluid either in parallel or in series to the ORC, and usually provide only low temperature heat, which is seldom suitable for industrial use. In this paper, a new CHP configuration, called Cross Parallel CHP, has been proposed and analyzed. It aims to provide higher temperature heat suitable for industrial use, allowing the exploitation of geothermal resources even in areas where district heating is not needed. The proposed CHP allows the reduction of the irreversibilities in the heat exchangers and the loss to the environment related to the re-injection of geofluid, thus producing higher electric power output while satisfying, at the same time, the heat demand of the thermal utility for a wide range of temperatures and mass flow rates (80–140 °C; 3–13 kg/s). Several organic fluids are investigated and the related optimizing working conditions are found by a built in procedure making use of genetic algorithms. The results show that the optimal working fluids and

New Geothermal Prospect in North-Eastern Morocco

OpenAIRE

Rimi, Abdelkrim; Correia, António; Carneiro, Júlio; Verdoya, Massimo; Zarhloule, Yassine; Lucazeau, Francis; Boughriba, Mimoun; Barkaoui, Alae Eddine

2010-01-01

Geothermal data has been indicating promising potentialities in the north-eastern Morocco. This paperpresents new temperature data, recently recorded in water borehole located in the Berkane and Oujda areas. Generally, the observed temperature gradients are rather high. One hole near Berkane, revealed an average geothermal gradient of more than 110 ºC/km at depths greater than 300 m. This result confirms the geothermal gradient estimated in a mining borehole located about 30 km west ...

Geothermal energy

International Nuclear Information System (INIS)

Kappelmeyer, O.

1991-01-01

Geothermal energy is the natural heat of the earth. It represents an inexhaustible source of energy. In many countries, which are mostly located within the geothermal belts of the world, geothermal energy is being used since many decades for electricity generation and direct heating applications comprising municipal, industrial and agricultural heating. Outside the geothermal anomalous volcanic regions, hot ground water from deep rock formations at temperatures above 70 o C is used for process heat and space heating. Low prices for gas and oil hinder the development of geothermal plants in areas outside positive geothermal anomalies; the cost of drilling to reach depths, where temperatures are above 50 o C to 70 o C, is high. The necessary total investment per MW th installed capacity is in the order of 5 Mio- DM/MW th (3 Mio $/MW th ). Experience shows, that an economic break even with oil is reached at an oil price of 30$ per barrel or if an adequate bonus for the clean, environmentally compatible production of geothermal heat is granted. Worldwide the installed electric capacity of geothermal power plants is approximately 6 000 MW e . About 15 000 MW th of thermal capacity is being extracted for process heat and space heat. The importance of the terrestrial heat as an energy resource would be substantially increased, if the heat, stored in the hot crystalline basement could be extracted at economical production costs. Geothermal energy is a competitive energy source in areas with high geothermal gradients (relative low cost for drilling) and would be competitive in areas with normal geothermal gradients, if a fair compensation for environmental implications from fossil and nuclear power production would be granted. (author) 2 figs., 1 tab., 6 refs

Hydrogeological Modelling of the Geothermal Waters of Alaşehir in the Continental Rift Zone of the Gediz, Western Anatolia, Turkey

Science.gov (United States)

Ӧzgür, Nevzat; Bostancı, Yesim; Anilır Yürük, Ezgi

2017-12-01

In western Anatolia, Turkey, the continental rift zones of the Büyük Menderes, Küçük Menderes and Gediz were formed by extensional tectonic features striking E-W generally and representing a great number of active geothermal systems, epithermal mineralizations and volcanic rocks from Middle Miocene to recent. The geothermal waters are associated with the faults which strike preferentially NW-SE and NE-SW and locate diagonal to general strike of the rift zones of the Menderes Massif. These NW-SE and NE-SW striking faults were probably generated by compressional tectonic regimes which leads to the deformation of uplift between two extensional rift zones in the Menderes Massif. The one of these rift zones is Gediz which is distinguished by a great number of geothermal waters such as Alaşehir, Kurşunlu, Çamurlu, Pamukkale and Urganlı. The geothermal waters of Alaşehir form the biggest potential in the rift zone of Gediz with a capacity of about 100 to 200 MWe. Geologically, the gneisses from the basement rocks in the study area which are overlain by an Paleozoic to Mesozoic intercalation of mica schists, quartzites and marbles, a Miocene intercalation of conglomerates, sandstones and clay stones and Plio-Quaternary intercalation of conglomerates, sandstones and clay stones discordantly. In the study area, Paleozoic to Mesozoic quartzites and marbles form the reservoir rocks hydrogeologically. The geothermal waters anions with Na+K>Ca>Mg dominant cations and HCO3>Cl> dominant anions are of Na-HCO3 type and can be considered as partial equilibrated waters. According to the results of geochemical thermometers, the reservoir temperatures area of about 185°C in accordance with measured reservoir temperatures. Stabile isotopes of δ18O versus δ2H of geothermal waters of Alaşehir deviate from the meteoric water line showing an intensive water-rock interaction under high temperature conditions. These data are well correlated with the results of the

Simulation of water-rock interaction in the yellowstone geothermal system using TOUGHREACT

International Nuclear Information System (INIS)

Dobson, P.F.; Salah, S.; Spycher, N.; Sonnenthal, E.

2003-01-01

The Yellowstone geothermal system provides an ideal opportunity to test the ability of reactive transport models to accurately simulate water-rock interaction. Previous studies of the Yellowstone geothermal system have characterized water-rock interaction through analysis of rocks and fluids obtained from both surface and downhole samples. Fluid chemistry, rock mineralogy, permeability, porosity, and thermal data obtained from the Y-8 borehole in Upper Geyser Basin were used to constrain a series of reactive transport simulations of the Yellowstone geothermal system using TOUGHREACT. Three distinct stratigraphic units were encountered in the 153.4 m deep Y-8 drill core: volcaniclastic sandstone, perlitic rhyolitic lava, and nonwelded pumiceous tuff. The main alteration phases identified in the Y-8 core samples include clay minerals, zeolites, silica polymorphs, adularia, and calcite. Temperatures observed in the Y-8 borehole increase with depth from sub-boiling conditions at the surface to a maximum of 169.8 C at a depth of 104.1 m, with near-isothermal conditions persisting down to the well bottom. 1-D models of the Y-8 core hole were constructed to determine if TOUGHREACT could accurately predict the observed alteration mineral assemblage given the initial rock mineralogy and observed fluid chemistry and temperatures. Preliminary simulations involving the perlitic rhyolitic lava unit are consistent with the observed alteration of rhyolitic glass to form celadonite

Geothermal characterization of the coastal aquifer near Ravenna (Italy

Directory of Open Access Journals (Sweden)

M. Antonellini

2012-12-01

Full Text Available The coastal aquifer near Ravenna (Italy contains a large volume of groundwater (2,5x109 m3 whose quality has been compromised by sea-water intrusion. Today, the phreatic groundwater is mostly brackish with some lenses of freshwater floating on top of more saline water. This water, although impossible to use as drink-water or for irrigation, is still important to guarantee the health of wetland habitats and especially of the roman historical and coastal pine forests of Ravenna. With the objective of defining the flow pattern within the aquifer and the exchange between surface and ground water, we characterized the temperature distribution in the shallow subsurface by means of a dense network of piezometers. At the same time we had the opportunity to characterize the phreatic aquifer from the geothermal point of view, so that it could eventually be considered for use as a “low enthalpy” heat source. Heat pumps are able to extract heat during the winter and dissipate it during the summer. The temperature of the groundwater in the top layer of the aquifer (surficial zone is sensitive to the changes in atmospheric temperature throughout the year whereas the temperature of the deeper groundwater follows the geothermal gradient (geothermal zone. One of the scopes of the project is to discover at what depth is located the geothermal zone, so that the aquifer has a constant temperature throughout the year. A constant temperature is needed for storage of heat at low enthalpy. The thickness of the surficial zone and the temperature at the top of the geothermal zone are essentially related to land use, distance from the sea, sediment type, and amount of interaction between surface and groundwater. A knowledge of these factors allows to better exploit the geothermal potential of the aquifer when choosing the optimal placement of the heat pumps.

Are modern geothermal waters in northwest Nevada forming epithermal gold deposits?

Science.gov (United States)

Breit, George N.; Hunt, Andrew G.; Wolf, Ruth E.; Koenig, Alan E.; Fifarek, Richard; Coolbaugh, Mark F.

2010-01-01

Hydrothermal systems currently are active near some gold deposits in northwestern Nevada. Possible links of these modern systems to gold mineralization were evaluated by chemically and isotopically analyzing water samples from the Brady, Dixie Valley, Humboldt House, San Emidio-Empire, Soda Lake, and Wabuska geothermal areas. In addition, quartz veins from Humboldt House and the adjacent Florida Canyon Mine were analyzed to compare ore and gangue phases with those predicted to form from proximal hydrothermal fluids.Nearly all water samples are alkali-chloride-type. Total dissolved solids range from 800 to 3900 mg/L, and pH varies from 5.6 to 7.8. Geochemical modeling with SOLVEQ, WATCH, and CHILLER predict the precipitation of silica in all systems during cooling. Anhydrite, calcite, barite, pyrite, base-metal sulfides, and alumino-silicates are variably saturated at calculated reservoir temperatures and also precipitate during boiling/cooling of some fluids. Measured dissolved gold concentrations are low (<0.2μg/L), but are generally consistent with contents predicted by equilibrium of sampled solutions with elemental gold at reservoir temperatures.  Although the modern geothermal waters can precipitate ore minerals, the low gold and other ore metal concentrations require very large fluid volumes to form a deposit of economic interest.

Preliminary geothermal investigations at Manley Hot Springs, Alaska

Energy Technology Data Exchange (ETDEWEB)

East, J.

1982-04-01

Manley Hot Springs is one of several hot springs which form a belt extending from the Seward Peninsula to east-central Alaska. All of the hot springs are low-temperature, water-dominated geothermal systems, having formed as the result of circulation of meteoric water along deepseated fractures near or within granitic intrusives. Shallow, thermally disturbed ground at Manley Hot Springs constitutes an area of 1.2 km by 0.6 km along the lower slopes of Bean Ridge on the north side of the Tanana Valley. This area includes 32 springs and seeps and one warm (29.1/sup 0/C) well. The hottest springs range in temperature from 61/sup 0/ to 47/sup 0/C and are presently utilized for space heating and irrigation. This study was designed to characterize the geothermal system present at Manley Hot Springs and delineate likely sites for geothermal drilling. Several surveys were conducted over a grid system which included shallow ground temperature, helium soil gas, mercury soil and resistivity surveys. In addition, a reconnaissance ground temperature survey and water chemistry sampling program was undertaken. The preliminary results, including some preliminary water chemistry, show that shallow hydrothermal activity can be delineated by many of the surveys. Three localities are targeted as likely geothermal well sites, and a model is proposed for the geothermal system at Manley Hot Springs.

Performance analyses of a hybrid geothermal–fossil power generation system using low-enthalpy geothermal resources

International Nuclear Information System (INIS)

Liu, Qiang; Shang, Linlin; Duan, Yuanyuan

2016-01-01

Highlights: • Geothermal energy is used to preheat the feedwater in a coal-fired power unit. • The performance of a hybrid geothermal–fossil power generation system is analyzed. • Models for both parallel and serial geothermal preheating schemes are presented. • Effects of geothermal source temperatures, distances and heat losses are analyzed. • Power increase of the hybrid system over an ORC and tipping distance are discussed. - Abstract: Low-enthalpy geothermal heat can be efficiently utilized for feedwater preheating in coal-fired power plants by replacing some of the high-grade steam that can then be used to generate more power. This study analyzes a hybrid geothermal–fossil power generation system including a supercritical 1000 MW power unit and a geothermal feedwater preheating system. This study models for parallel and serial geothermal preheating schemes and analyzes the thermodynamic performance of the hybrid geothermal–fossil power generation system for various geothermal resource temperatures. The models are used to analyze the effects of the temperature matching between the geothermal water and the feedwater, the heat losses and pumping power during the geothermal water transport and the resource distance and temperature on the power increase to improve the power generation. The serial geothermal preheating (SGP) scheme generally generates more additional power than the parallel geothermal preheating (PGP) scheme for geothermal resource temperatures of 100–130 °C, but the SGP scheme generates slightly less additional power than the PGP scheme when the feedwater is preheated to as high a temperature as possible before entering the deaerator for geothermal resource temperatures higher than 140 °C. The additional power decreases as the geothermal source distance increases since the pipeline pumping power increases and the geothermal water temperature decreases due to heat losses. More than 50% of the power decrease is due to geothermal

Preliminary geothermal study of Mt. Etna

Energy Technology Data Exchange (ETDEWEB)

Mongelli, F; Morelli, C

1964-01-01

The geothermal status of Italy's Mt. Etna region was studied via borehole thermometry at eight experimental sites. The mathematical principles and other criteria used in borehole site and well depth selection are discussed. The soil temperature is regulated by external temperature variations to a certain depth. The minimum drilling distance which would provide accurate temperature determinations was calculated to be 30 m. The geothermal gradient was determined by the application of a Fourier series to three measurements made at different depths using resistance thermometers. The results are presented in tables and the gradients are plotted on graphs. Geothermal gradient determinations were corrected for topographic effects. Two major groups of gradients were discovered, those having linear gradients were interpreted as being due to the effect of meteoric waters. Other possible disturbances are those caused by surface temperature effects and the influence of nearby bodies of water.

Radiator Enhanced Geothermal System - A Revolutionary Method for Extracting Geothermal Energy

Science.gov (United States)

Karimi, S.; Marsh, B. D.; Hilpert, M.

2017-12-01

A new method of extracting geothermal energy, the Radiator Enhanced Geothermal System (RAD-EGS) has been developed. RAD-EGS attempts to mimic natural hydrothermal systems by 1) generating a vertical vane of artificially produced high porosity/permeability material deep in a hot sedimentary aquifer, 2) injecting water at surface temperatures to the bottom of the vane, where the rock is the hottest, 3) extracting super-heated water at the top of the vane. The novel RAD-EGS differs greatly from the currently available Enhanced Geothermal Systems in vane orientation, determined in the governing local crustal stress field by Shmax and Sl (meaning it is vertical), and in the vane location in a hot sedimentary aquifer, which naturally increases the longevity of the system. In this study, we explore several parameters regimes affecting the water temperature in the extraction well, keeping in mind that the minimum temperature of the extracted water has to be 150 °C in order for a geothermal system to be commercially viable. We used the COMSOL finite element package to simulate coupled heat and fluid transfer within the RAD-EGS model. The following geologic layers from top to bottom are accounted for in the model: i) confining upper layer, ii) hot sedimentary aquifer, and iii) underlying basement rock. The vane is placed vertically within the sedimentary aquifer. An injection well and an extraction well are also included in the simulation. We tested the model for a wide range of various parameters including background heat flux, thickness of geologic layers, geometric properties of the vane, diameter and location of the wells, fluid flow within the wells, regional hydraulic gradient, and permeability and porosity of the layers. The results show that among the aforementioned parameters, background heat flux and the depth of vane emplacement are highly significant in determining the level of commercial viability of the geothermal system. These results indicate that for the

Temporal variability of secondary processes in alkaline geothermal waters associated to granitic rocks: the Caldes de Boí geothermal system (Spain)

International Nuclear Information System (INIS)

Asta, M.; Gimeno, M.J.; Auqué, L.F.; Galve, J.P.; Gómez, J.; Acero, P.; Lapuente, P.

2017-01-01

The Caldes de Boí geothermal waters show important differences in pH (6.5–9.6) and temperature (15.9ºC–52ºC) despite they have a common origin and a very simple circuit at depth (4km below the recharge area level). Thes differences are the result of secondary processes such as conductive cooling, mixing with colder shallower waters, and input of external CO2, which affect each spring to a different extent in the terminal part of the thermal circuit. In this paper, the secondary processes that control the geochemical evolution of this system have been addressed using a geochemical dataset spanning over 20 years and combining different approaches: classical geochemical calculations and geochemical modelling. Mixing between a cold and a thermal end-member, cooling and CO2 exchange are the processes affecting the spring waters with different intensity over time. These differences in the intensity of the secondary processes could be controlled by the effect of climate and indirectly by the geomorphological and hydrogeological setting of the different springs. Infiltration recharging the shallow aquifer is dominant during the rainy seasons and the extent of the mixing process is greater, at least in some springs.Moreover, significant rainfall can produce a decrease in the ground temperature favouring the conductive cooling. Finally, the geomorphological settings of the springs determine the thickness and the hydraulic properties of the saturated layer below them and, therefore, they affect the extent of the mixing process between the deep thermal waters and the shallower cold waters. The understanding of the compositional changes in the thermal waters and the main factors that could affect them is a key issue to plan the future management of the geothermal resources of the Caldes de Boí system. Here, we propose to use a simple methodology to assess the effect of those factors, which could affect the quality of the thermal waters for balneotherapy at long

Temporal variability of secondary processes in alkaline geothermal waters associated to granitic rocks: the Caldes de Boí geothermal system (Spain)

Energy Technology Data Exchange (ETDEWEB)

Asta, M.; Gimeno, M.J.; Auqué, L.F.; Galve, J.P.; Gómez, J.; Acero, P.; Lapuente, P.

2017-11-01

The Caldes de Boí geothermal waters show important differences in pH (6.5–9.6) and temperature (15.9ºC–52ºC) despite they have a common origin and a very simple circuit at depth (4km below the recharge area level). Thes differences are the result of secondary processes such as conductive cooling, mixing with colder shallower waters, and input of external CO2, which affect each spring to a different extent in the terminal part of the thermal circuit. In this paper, the secondary processes that control the geochemical evolution of this system have been addressed using a geochemical dataset spanning over 20 years and combining different approaches: classical geochemical calculations and geochemical modelling. Mixing between a cold and a thermal end-member, cooling and CO2 exchange are the processes affecting the spring waters with different intensity over time. These differences in the intensity of the secondary processes could be controlled by the effect of climate and indirectly by the geomorphological and hydrogeological setting of the different springs. Infiltration recharging the shallow aquifer is dominant during the rainy seasons and the extent of the mixing process is greater, at least in some springs.Moreover, significant rainfall can produce a decrease in the ground temperature favouring the conductive cooling. Finally, the geomorphological settings of the springs determine the thickness and the hydraulic properties of the saturated layer below them and, therefore, they affect the extent of the mixing process between the deep thermal waters and the shallower cold waters. The understanding of the compositional changes in the thermal waters and the main factors that could affect them is a key issue to plan the future management of the geothermal resources of the Caldes de Boí system. Here, we propose to use a simple methodology to assess the effect of those factors, which could affect the quality of the thermal waters for balneotherapy at long

Culture of Freshwater Prawns (Macrobrachium Rosenbergii) Using Geothermal Waste Water

Energy Technology Data Exchange (ETDEWEB)

Johnson, William C

1978-01-01

The farming of freshwater prawns (Macrobrachium rosenbergii) in geothermal-heated water has been demonstrated to be feasible in a non-tropical climate. The husbandry of prawns is being done in two outdoor raceway ponds, 9.1 m by 2.5 m and 29 m by 3.5 m that are 1.2 m deep. The ponds are not shielded from the ambient climate which during the winter months has recorded air temperatures as low as -20oC. A selected brood stock is held in a small spawning building where larvae are hatched in artificial saltwater and reared to the post-larvae stage which makes the facility self-supporting. This project is providing a model for potential investors to utilize the low-temperature geothermal resources in the western United States for warm water aquaculture. Zooplankton, macroscopic crusteans, from a local euthrophic lake are being fed to the post-larvae and adult prawns in addition to prepared commercial dry pelleted foods to keep operational costs at a minimum. Initial measurements of growth and weight gains indicate the production of two crops of prawns per year at seven to the pond is possible. No work on intensive culture has been done. Plans to enlarge the facility and do work on developing intensive culture are being considered.

Geothermal gradients in Iraqi Kurdistan deduced from bottom hole temperatures

Directory of Open Access Journals (Sweden)

Rzger A. Abdula

2017-09-01

Full Text Available Bottom hole temperature (BHT data from 12 oil wells in Iraqi Kurdistan were used to obtain the thermal trend of Iraqi Kurdistan. Due to differences in thermal conductivity of rocks and groundwater movement, variations in geothermal gradients were observed. The highest geothermal gradient (29.2 °C/km was found for well Taq Taq-8 in the Low Folded Zone (central part of the area. The lowest geothermal gradients (14.9 °C/km were observed for well Bekhme-1 in the High Folded Zone (northern and northeastern parts of the area. The average regional geothermal gradient for Iraqi Kurdistan is 21 °C/km.

Coordination of geothermal research

Energy Technology Data Exchange (ETDEWEB)

Jessop, A.M.; Drury, M.J.

1983-01-01

Visits were made in 1983 to various investigators and institutions in Canada to examine developments in geothermal research. Proposals for drilling geothermal wells to provide hot water for heating at a college in Prince Edward Island were made. In Alberta, the first phase of a program examining the feasibility of mapping sedimentary geothermal reservoirs was discussed. Some sites for possible geothermal demonstration projects were identified. In British Columbia, discussions were held between BC Hydro and Energy, Mines and Resources Canada on the drilling of a research hole into the peak of a temperature anomaly in the Meager Creek Valley. The British Columbia government has offered blocks of land in the Mount Cayley volcanic complex for lease to develop geothermal resources. A list of papers of interest to the Canadian geothermal energy program is appended.

Modeling of a deep-seated geothermal system near Tianjin, China.

Science.gov (United States)

Xun, Z; Mingyou, C; Weiming, Z; Minglang, L

2001-01-01

A geothermal field is located in deep-seated basement aquifers in the northeastern part of the North China Plain near Tianjin, China. Carbonate rocks of Ordovician and Middle and Upper Proterozoic age on the Cangxian Uplift are capable of yielding 960 to 4200 m3/d of 57 degrees C to 96 degrees C water to wells from a depth of more than 1000 m. A three-dimensional nonisothermal numerical model was used to simulate and predict the spatial and temporal evolution of pressure and temperature in the geothermal system. The density of the geothermal water, which appears in the governing equations, can be expressed as a linear function of pressure, temperature, and total dissolved solids. A term describing the exchange of heat between water and rock is incorporated in the governing heat transport equation. Conductive heat flow from surrounding formations can be considered among the boundary conditions. Recent data of geothermal water production from the system were used for a first calibration of the numerical model. The calibrated model was used to predict the future changes in pressure and temperature of the geothermal water caused by two pumping schemes. The modeling results indicate that both pressure and temperature have a tendency to decrease with time and pumping. The current withdrawal rates and a pumping period of five months followed by a shut-off period of seven months are helpful in minimizing the degradation of the geothermal resource potential in the area.

Assessment of geothermal resources of the United States, 1978

Energy Technology Data Exchange (ETDEWEB)

Muffler, L.J.P. (ed.)

1979-01-01

The geothermal resource assessment presented is a refinement and updating of USGS Circular 726. Nonproprietary information available in June 1978 is used to assess geothermal energy in the ground and, when possible, to evaluate the fraction that might be recovered at the surface. Five categories of geothermal energy are discussed: conduction-dominated regimes, igneous-related geothermal systems, high-temperature (> 150/sup 0/C) and intermediate-temperature (90 to 150/sup 0/C) hydrothermal convection systems, low-temperature (< 90/sup 0/C) geothermal waters, and geopressured-geothermal energy (both thermal energy and energy from dissolved methane). Assessment data are presented on three colored maps prepared in cooperation with the National Oceanic and Atmospheric Administration. Separate abstracts were prepared for papers on these five categories.

Drilling Addendum to Resource Assessment of Low- and Moderate-Temperature Geothermal Waters in Calistoga, Napa County, California

Energy Technology Data Exchange (ETDEWEB)

Taylor, Gary C.; Bacon, C. Forrest; Chapman, Rodger H.; Chase, Gordon W.; Majmundar, Hasmukhrai H.

1981-05-01

This addendum report presents the results of the California Division of Mines and Geology (CDMG) drilling program at Calistoga, California, which was the final geothermal-resource assessment investigation performed under terms of the second year contract (1979-80) between the U.S. Department of Energy (DOE) and the CDMG under the State Coupled Program. This report is intended to supplement information presented in CDMG's technical report for the project year, ''Resource Assessment of Low- and Moderate-Temperature Geothermal Waters in Calistoga, Napa County, California''. During the investigative phase of the CDMG's Geothermal Project, over 200 well-driller's reports were obtained from the Department of Water Resources (DWR). It was hoped that the interpretation and correlation of these logs would reveal the subsurface geology of the Upper Napa Valley and also provide a check for the various geophysical surveys that were performed in the course of the study. However, these DWR driller logs proved to be inadequate due to the brief, non-technical, and erroneous descriptions contained on the logs. As a result of the lack of useable drill-hole data, and because information was desired from,deeper horizons, it became evident that drilling some exploratory holes would be necessary in order to obtain physical evidence of the stratigraphy and aquifers in the immediate Calistoga area. Pursuant to this objective, a total of twelve sites were selected--four under jurisdiction of Napa County and eight under jurisdiction of the City of Calistoga. A moratorium is currently in existence within Napa County on most geothermal drilling, and environmental and time constraints precluded CDMG from obtaining the necessary site permits within the county. However, a variance was applied for and obtained from the City of Calistoga to allow CDMG to drill within the city limits. With this areal constraint and also funding limits in mind, six drilling sites

Direct uses of hot water (geothermal) in dairying

Energy Technology Data Exchange (ETDEWEB)

Barmettler, E.R.; Rose, W.R. Jr.

1978-01-01

Digital computer simulation was used to investigate the peak, steady energy utilization of a geothermal energy-supported dairy. A digital computer program was also written to assess the lifetime economics of the dairy operation. A dynamic simulation program was written to design water storage tanks under diurnal transient loading. The geothermal site specified is the artesian spring named Hobo Wells near Susanville, California. The dairy configuration studies are unique, but consist of conventional processing equipment. In the dairy, cattle waste would be used to generate methane and carbon dioxide by anaerobic digestion. Some carbon dioxide would be removed from the gas stream with a pressurized water scrubber to raise the heating value. The product gas would be combusted in a spark ignition engine connected to an electric generator. The electrical power produced would be used for operation of fans, pumps, lights and other equipment in the dairy. An absorption chiller using a geothermal water driven generator would provide milk chilling. Space heating would be done with forced air hot water unit heaters.

Characteristics of geothermal structures of Poprad basin in terms of numerical modeling

International Nuclear Information System (INIS)

Bagelova, A.; Fendek, M.

2011-01-01

Poprad basin is one of the promising areas in terms of geothermal resources. In terms of impact on the environment and the exploitation of geothermal waters it is important to quantify the natural geothermal water quantity. One of the most progressive methods of their evaluation is a method of numerical modelling. Before model creation it is necessary to characterize the geothermal structure. Character of hydro-geothermal structure consists of an analysis of Spatial distribution of collectors, hydraulic properties of collectors of geothermal water, pressure and temperature conditions and boundary conditions. Basic characteristics of geothermal energy transfer in the Poprad basin are described. (authors)

CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

Directory of Open Access Journals (Sweden)

Nediljka Gaurina-Međimurec

1994-12-01

Full Text Available During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production, pipe corrosion and expensive well repairs. Cementing temperature conditions are important because bot-tomhole circulating temperatures affect slurry thickening time, arheology, set time and compressive strength development. Knowing the actual temperature which cement encounters during placement allows the selection of proper cementing materials for a specific application. Slurry design is affected by well depth, bottom hole circulating temperature and static temperature, type or drilling fluid, slurry density, pumping time, quality of mix water, fluid loss control, flow regime, settling and free water, quality of cement, dry or liquid additives, strength development, and quality of the lab cement testing and equipment. Most Portland cements and Class J cement have shown suitable performances in geot-hermal wells. Cement system designs for geothermal wells differ from those for conventional high temperature oil and gas wells in the exclusive use of silica flour instead of silica sand, and the avoidance of fly ash as an extender. In this paper, Portland cement behaviour at high temperatures is described. Cement slurry and set cement properties are also described. Published in literature, the composition of cement slurries which were tested in geothermal conditions and which obtained required compressive strength and water permeability are listed. As a case of our practice geothermal wells Velika Ciglena-1 and Velika Ciglena-la are described.

Energy efficiency comparison between geothermal power systems

Directory of Open Access Journals (Sweden)

Luo Chao

2017-01-01

Full Text Available The geothermal water which can be considered for generating electricity with the temperature ranging from 80℃ to 150℃ in China because of shortage of electricity and fossil energy. There are four basic types of geothermal power systems: single flash, double flash, binary cycle, and flash-binary system, which can be adapted to geothermal energy utilization in China. The paper discussed the performance indices and applicable conditions of different power system. Based on physical and mathematical models, simulation result shows that, when geofluid temperature ranges from 100℃ to 130℃, the net power output of double flash power is bigger than flash-binary system. When the geothermal resource temperature is between 130℃ and 150℃, the net power output of flash-binary geothermal power system is higher than double flash system by the maximum value 5.5%. However, the sum water steam amount of double flash power system is 2 to 3 times larger than flash-binary power system, which will cause the bigger volume of equipment of power system. Based on the economy and power capacity, it is better to use flash-binary power system when the geofluid temperature is between 100℃ and 150℃.

Direct use of low temperature geothermal water by Aquafarms International, Inc. for freshwater aquaculture (prawns and associated species). An operations and maintenance manual

Energy Technology Data Exchange (ETDEWEB)

Broughton, R.; Price, M.; Price, V.; Grajcer, D.

1984-04-01

In connection with an ongoing commercial aquaculture project in the Coachella Valley, California; a twelve month prawn growout demonstration project was conducted. This project began in August, 1979 and involved the use of low temperature (85/sup 0/F) geothermal waters to raise freshwater prawns, Macrobrachium rosenbergii (deMan), in earthen ponds. The following publication is an operations and maintenance guide which may by useful for those interested in conducting similar enterprises.

Geothermal gradients in Iraqi Kurdistan deduced from bottom hole temperatures

OpenAIRE

Abdula, Rzger A.

2016-01-01

Bottom hole temperature (BHT) data from 12 oil wells in Iraqi Kurdistan were used to obtain the thermal trend of Iraqi Kurdistan. Due to differences in thermal conductivity of rocks and groundwater movement, variations in geothermal gradients were observed. The highest geothermal gradient (29.2 °C/km) was found for well Taq Taq-8 in the Low Folded Zone (central part of the area). The lowest geothermal gradients (14.9 °C/km) were observed for well Bekhme-1 in the High Folded Zone (northern and...

Recovery Act: High-Temperature Circuit Boards for use in Geothermal Well Monitoring Applications

Energy Technology Data Exchange (ETDEWEB)

Hooker, Matthew [Composite Tehcnology Development, Inc., Lafayette, CO (United States); Fabian, Paul [Composite Tehcnology Development, Inc., Lafayette, CO (United States)

2013-05-01

The U.S. Department of Energy is leading the development of alternative energy sources that will ensure the long-term energy independence of our nation. One of the key renewable resources currently being advanced is geothermal energy. To tap into the large potential offered by generating power from the heat of the earth, and for geothermal energy to be more widely used, it will be necessary to drill deeper wells to reach the hot, dry rock located up to 10 km beneath the earth’s surface. In this instance, water will be introduced into the well to create a geothermal reservoir. A geothermal well produced in this manner is referred to as an enhanced geothermal system (EGS). EGS reservoirs are typically at depths of 3 to 10 km, and the temperatures at these depths have become a limiting factor in the application of existing downhole technologies. These high temperatures are especially problematic for electronic systems such as downhole data-logging tools, which are used to map and characterize the fractures and high-permeability regions in underground formations. Information provided by these tools is assessed so that underground formations capable of providing geothermal energy can be identified, and the subsequent drilling operations can be accurately directed to those locations. The mapping of geothermal resources involves the design and fabrication of sensor packages, including the electronic control modules, to quantify downhole conditions (300°C temperature, high pressure, seismic activity, etc.). Because of the extreme depths at which these measurements are performed, it is most desirable to perform the sensor signal processing downhole and then transmit the information to the surface. This approach necessitates the use of high-temperature electronics that can operate in the downhole environment. Downhole signal processing in EGS wells will require the development and demonstration of circuit boards that can withstand the elevated temperatures found at these

The Preston Geothermal Resources; Renewed Interest in a Known Geothermal Resource Area

Energy Technology Data Exchange (ETDEWEB)

Wood, Thomas R. [Univ. of Idaho, Idaho Falls, ID (United States); Worthing, Wade [Univ. of Idaho, Idaho Falls, ID (United States); Cannon, Cody [Univ. of Idaho, Idaho Falls, ID (United States); Palmer, Carl [Univ. of Idaho, Idaho Falls, ID (United States); Neupane, Ghanashyam [Idaho National Lab. (INL), Idaho Falls, ID (United States); McLing, Travis L [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Mattson, Earl [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Dobson, Patric [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Conrad, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.

2015-01-01

The Preston Geothermal prospect is located in northern Cache Valley approximately 8 kilometers north of the city of Preston, in southeast Idaho. The Cache Valley is a structural graben of the northern portion of the Basin and Range Province, just south of the border with the Eastern Snake River Plain (ESRP). This is a known geothermal resource area (KGRA) that was evaluated in the 1970's by the State of Idaho Department of Water Resources (IDWR) and by exploratory wells drilled by Sunedco Energy Development. The resource is poorly defined but current interpretations suggest that it is associated with the Cache Valley structural graben. Thermal waters moving upward along steeply dipping northwest trending basin and range faults emanate in numerous hot springs in the area. Springs reach temperatures as hot as 84° C. Traditional geothermometry models estimated reservoir temperatures of approximately 125° C in the 1970’s study. In January of 2014, interest was renewed in the areas when a water well drilled to 79 m (260 ft) yielded a bottom hole temperature of 104° C (217° F). The well was sampled in June of 2014 to investigate the chemical composition of the water for modeling geothermometry reservoir temperature. Traditional magnesium corrected Na-K-Ca geothermometry estimates this new well to be tapping water from a thermal reservoir of 227° C (440° F). Even without the application of improved predictive methods, the results indicate much higher temperatures present at much shallower depths than previously thought. This new data provides strong support for further investigation and sampling of wells and springs in the Northern Cache Valley, proposed for the summer of 2015. The results of the water will be analyzed utilizing a new multicomponent equilibrium geothermometry (MEG) tool called Reservoir Temperature Estimate (RTEst) to obtain an improved estimate of the reservoir temperature. The new data suggest that other KGRAs and overlooked areas may need

Application of low enthalpy geothermal energy

International Nuclear Information System (INIS)

Stancher, B.; Giannone, G.

2007-01-01

Geothermal energy comes from the superficial layers of the Earth's crust; it can be exploited in several ways, depending on its temperature. Many systems have been developed to use this clean and renewable energy resource. This paper deals with a particular application of low enthalpy geothermal energy in Latisana (district of Udine NE, Italy). The Latisana's indoor stadium is equipped with geothermal plant that uses low temperature water (29-30 0 ) to provide heating. Economic analysis shows that the cost of its plant is comparable to the cost powered by other kinds of renewable energy resources

Mapping temperature and radiant geothermal heat flux anomalies in the Yellowstone geothermal system using ASTER thermal infrared data

Science.gov (United States)

Vaughan, R. Greg; Lowenstern, Jacob B.; Keszthelyi, Laszlo P.; Jaworowski, Cheryl; Heasler, Henry

2012-01-01

The purpose of this work was to use satellite-based thermal infrared (TIR) remote sensing data to measure, map, and monitor geothermal activity within the Yellowstone geothermal area to help meet the missions of both the U.S. Geological Survey Yellowstone Volcano Observatory and the Yellowstone National Park Geology Program. Specifically, the goals were to: 1) address the challenges of remotely characterizing the spatially and temporally dynamic thermal features in Yellowstone by using nighttime TIR data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and 2) estimate the temperature, geothermal radiant emittance, and radiant geothermal heat flux (GHF) for Yellowstone’s thermal areas (both Park wide and for individual thermal areas). ASTER TIR data (90-m pixels) acquired at night during January and February, 2010, were used to estimate surface temperature, radiant emittance, and radiant GHF from all of Yellowstone’s thermal features, produce thermal anomaly maps, and update field-based maps of thermal areas. A background subtraction technique was used to isolate the geothermal component of TIR radiance from thermal radiance due to insolation. A lower limit for the Yellowstone’s total radiant GHF was established at ~2.0 GW, which is ~30-45% of the heat flux estimated through geochemical (Cl-flux) methods. Additionally, about 5 km2 was added to the geodatabase of mapped thermal areas. This work provides a framework for future satellite-based thermal monitoring at Yellowstone as well as exploration of other volcanic / geothermal systems on a global scale.

Performance analyses of geothermal organic Rankine cycles with selected hydrocarbon working fluids

International Nuclear Information System (INIS)

Liu, Qiang; Duan, Yuanyuan; Yang, Zhen

2013-01-01

ORC (organic Rankine cycles) are promising systems for conversion of low temperature geothermal energy to electricity. The thermodynamic performance of the ORC with a wet cooling system is analyzed here using hydrocarbon working fluids driven by geothermal water from 100 °C to 150 °C and reinjection temperatures not less than 70 °C. The hydrocarbon working fluids are butane (R600), isobutane (R600a), pentane (R601), isopentane (R601a) and hexane. For each fluid, the ORC net power output first increases and then decreases with increasing turbine inlet temperature. The turbine inlet parameters are then optimized for the maximum power output. The ORC net power output increases as the condensation temperature decreases but the circulating pump power consumption increases especially for lower condensation temperatures at higher cooling water flow rates. The optimal condensation temperatures for the maximum plant power output are 29.45–29.75 °C for a cooling water inlet temperature of 20 °C and a pinch point temperature difference of 5 °C in the condenser. The maximum power is produced by an ORC using R600a at geothermal water inlet temperatures higher than 120 °C, followed by R245fa and R600 for reinjection temperatures not less than 70 °C. R600a also has the highest plant exergetic efficiency with the lowest turbine size factor. - Highlights: • ORC (organic Rankine cycles) using geothermal water from 100 to 150 °C and reinjection temperatures not less than 70 °C are analyzed. • Condensation temperatures optimized to maximize the plant power output. • An IHE (internal heat exchanger) gives higher plant power at low geothermal water temperatures and high reinjection temperatures. • ORC performance optimized considering the condensation and reinjection temperature. • R600a gives the best performance at the optimal turbine operating parameters

The chemistry and isotopic composition of waters in the low-enthalpy geothermal system of Cimino-Vico Volcanic District, Italy

DEFF Research Database (Denmark)

Battistel, Maria; Hurwitz, Shaul; Evans, William C.

2016-01-01

Geothermal energy exploration is based in part on interpretation of the chemistry, temperature, and discharge rate of thermal springs. Here we present the major element chemistry and the δD, δ18O, 87Sr/86Sr and δ11B isotopic ratio of groundwater from the low-enthalpy geothermal system near the city...... and tortuous ascent enhances extraction of boron but also promotes conductive cooling, partially masking the heat present in the reservoir. Overall data from this study is consistent with previous studies that concluded that the geothermal system has a large energy potential....... of Viterbo in the Cimino-Vico volcanic district of west-Central Italy. The geothermal system hosts many thermal springs and gas vents, but the resource is still unexploited. Water chemistry is controlled by mixing between low salinity,HCO3-rich fresh waters (

Geothermal heat exchanger with coaxial flow of fluids

Directory of Open Access Journals (Sweden)

Pejić Dragan M.

2005-01-01

Full Text Available The paper deals with a heat exchanger with coaxial flow. Two coaxial pipes of the secondary part were placed directly into a geothermal boring in such a way that geothermal water flows around the outer pipe. Starting from the energy balance of the exchanger formed in this way and the assumption of a study-state operating regime, a mathematical model was formulated. On the basis of the model, the secondary circle output temperature was determined as a function of the exchanger geometry, the coefficient of heat passing through the heat exchange areas, the average mass isobaric specific heats of fluid and mass flows. The input temperature of the exchanger secondary circle and the temperature of the geothermal water at the exit of the boring were taken as known values. Also, an analysis of changes in certain factors influencing the secondary water temperature was carried out. The parameters (flow temperature of the deep boring B-4 in Sijarinska Spa, Serbia were used. The theoretical results obtained indicate the great potential of this boring and the possible application of such an exchanger.

Energy and Exergy Analyses of a New Combined Cycle for Producing Electricity and Desalinated Water Using Geothermal Energy

Directory of Open Access Journals (Sweden)

Mehri Akbari

2014-04-01

Full Text Available A new combined cogeneration system for producing electrical power and pure water is proposed and analyzed from the viewpoints of thermodynamics and economics. The system uses geothermal energy as a heat source and consists of a Kalina cycle, a LiBr/H2O heat transformer and a water purification system. A parametric study is carried out in order to investigate the effects on system performance of the turbine inlet pressure and the evaporator exit temperature. For the proposed system, the first and second law efficiencies are found to be in the ranges of 16%–18.2% and 61.9%–69.1%, respectively. For a geothermal water stream with a mass flow rate of 89 kg/s and a temperature of 124 °C, the maximum production rate for pure water is found to be 0.367 kg/s.

Natural radioactivity levels of geothermal waters and their influence on soil and agricultural activities.

Science.gov (United States)

Murat Saç, Müslim; Aydemir, Sercan; Içhedef, Mutlu; Kumru, Mehmet N; Bolca, Mustafa; Ozen, Fulsen

2014-01-01

All over the world geothermal sources are used for different purposes. The contents of these waters are important to understand positive/negative effects on human life. In this study, natural radioactivity concentrations of geothermal waters were investigated to evaluate the effect on soils and agricultural activities. Geothermal water samples were collected from the Seferihisar Geothermal Region, and the radon and radium concentrations of these waters were analysed using a collector chamber method. Also soil samples, which are irrigated with geothermal waters, were collected from the surroundings of geothermal areas, and natural radioactivity concentrations of collected samples (U, Th and K) were determined using an NaI(Tl) detector system. The activity concentrations of radon and radium were found to be 0.6-6.0 and 0.1-1.0 Bq l(-1), respectively. Generally, the obtained results are not higher compared with the geothermal waters of the world. The activity concentrations in soils were found to be in the range of 3.3-120.3 Bq kg(-1) for (226)Ra (eU), 0.3-108.5 Bq kg(-1) for (232)Th (eTh), 116.0-850.0 Bq kg(-1) for (40)K (% K).

Water use in the development and operation of geothermal power plants.

Energy Technology Data Exchange (ETDEWEB)

Clark, C. E.; Harto, C. B.; Sullivan, J. L.; Wang, M. Q. (Energy Systems); ( EVS)

2010-09-17

Geothermal energy is increasingly recognized for its potential to reduce carbon emissions and U.S. dependence on foreign oil. Energy and environmental analyses are critical to developing a robust set of geothermal energy technologies. This report summarizes what is currently known about the life cycle water requirements of geothermal electric power-generating systems and the water quality of geothermal waters. It is part of a larger effort to compare the life cycle impacts of large-scale geothermal electricity generation with other power generation technologies. The results of the life cycle analysis are summarized in a companion report, Life Cycle Analysis Results of Geothermal Systems in Comparison to Other Power Systems. This report is divided into six chapters. Chapter 1 gives the background of the project and its purpose, which is to inform power plant design and operations. Chapter 2 summarizes the geothermal electricity generation technologies evaluated in this study, which include conventional hydrothermal flash and binary systems, as well as enhanced geothermal systems (EGS) that rely on engineering a productive reservoir where heat exists but water availability or permeability may be limited. Chapter 3 describes the methods and approach to this work and identifies the four power plant scenarios evaluated: a 20-MW EGS plant, a 50-MW EGS plant, a 10-MW binary plant, and a 50-MW flash plant. The two EGS scenarios include hydraulic stimulation activities within the construction stage of the life cycle and assume binary power generation during operations. The EGS and binary scenarios are assumed to be air-cooled power plants, whereas the flash plant is assumed to rely on evaporative cooling. The well field and power plant design for the scenario were based on simulations using DOE's Geothermal Economic Technology Evaluation Model (GETEM). Chapter 4 presents the water requirements for the power plant life cycle for the scenarios evaluated. Geology

New Mexico low-temperature geothermal resources and economic development programs

International Nuclear Information System (INIS)

Whittier, J.; Schoenmackers, R.

1990-01-01

This paper reports on New Mexico's low-temperature geothermal resources which have been utilized to promote economic development initiatives within the state. Public funds have been leveraged to foster exploration activities which have led to the establishment of several direct-use projects at various sites within New Mexico. State policies have focused on attracting one business sector, the commercial greenhouse industry, to expand and/or relocate in New Mexico. Geothermal-related promotional activities have begun to show success in achieving economic growth. New Mexico now has almost half of the geothermally-heated greenhouse space in the nation. It is anticipated that the greenhouse sector will continue to grow within the state. Future economic development activities, also relying upon the geothermal resource base, will include vegetable dehydration and aquaculture with a focus on the microalgae sector

Goechemical and Hydrogeochemical Properties of Cappadocia Geothermal Province

Science.gov (United States)

Furkan Sener, Mehmet; Sener, Mehmet; Uysal, Tonguc

2016-04-01

In order to determine the geothermal resource potential of Niǧde, Nevşehir and Aksaray provinces in Central Anatolian Volcanic Province (CAVP), geothermal fluids, surface water, and alteration rock samples from the Cappadocia volcanic zone in Turkey were investigated for their geochemical and stable isotopic characteristics in light of published geological and tectonic studies. Accordingly, the Cappadocia Geothermal Province (CGP) has two different geothermal systems located along tectonic zones including five active and two potential geothermal fields, which are located between Tuzgölü Fault Zone and Keçiboyduran-Melendiz Fault and north of Keçiboyduran-Melendiz Fault. Based on water chemistry and isotope compositions, samples from the first area are characterized by Ca-Mg-HCO3 ve Ca-HCO3 type mineral poor waters and Ca-Na-SO4 and Ca-Mg-SO4 type for the cold waters and the hot waters, respectively, whereas hot waters from the second area are Na-Cl-HCO3 and Ca-Na-HCO3 type mineral poor waters. According to δ18O and δ2H isotope studies, the geothermal waters are fed from meteoric waters. Results of silica geothermometer indicate that the reservoir temperature of Dertalan, Melendiz Mount, Keçiboyduran Mount, Hasan Mount (Keçikalesi), Ziga, Acıgöl, and Derinkuyu geothermal waters are 150-173 oC, 88-117 oC, 91-120 oC, 94-122 oC, 131-156 oC, 157-179 oC; 152-174 oC and 102-130 oC, respectively. The REE composition of geothermal fluids, surface water, and mineral precipitates indicate that temperature has a strong effect on REE fractionation of the sampled fluids. Eu- and Ce- anomalies (Eu/Eu*, Ce/Ce*) are visible in several samples, which are related to the inheritance from the host reservoir rocks and redox-controlled fractionation of these elements during water-rock interactions. REE and Yttrium geochemistry results of altered rock samples and water samples, which were taken from same locations exhibited quite similar features in each system. Hence, it was

FY 1992 report on the survey of geothermal development promotion. Geochemical survey (Survey of geothermal water) (No.36 - Hongu area); 1992 nendo chinetsu kaihatsu sokushin chosa. Chikagaku chosa (Nessui no chosa) hokokusho (No.36 Hongu chiiki)

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-07-01

The test on jetting of geothermal water by the induced jetting, sampling of geothermal water and analysis/survey were carried out in the structure drilling well of N4-HG-2 in the Hongu area, Wakayama Prefecture. The induced jetting of the well was conducted by the Swabbing method up to the total pumping amount of 459.9m{sup 3} that is equal to about 24 times as much as the inner quantity of the well, but it did not result in jetting. The maximum temperature of geothermal water was 65.6 degrees C, pH was 6.6-7.5, electric conductivity was 2,800-2,900 {mu}S/cm, and Cl concentration was 500-700ppm. The geothermal water was classified into the HCO{sub 3} type that is neutral, and the spring quality and liquidity were the same as those of existing hot springs in this area. In the Hongu area, the distribution of new volcanic rocks has not known. The K-Ar age of quartz porphyry intrusive rocks was made about 13Ma, and it was considered that a possibility was low of the rocks being heat sources of geothermal activities. It was also considered that the geothermal water/hot spring water in this area, which originate in the surface water, were heated in heat transfer by magma activities in the deep underground and were flowing forming a small scale of hydrothermal convection system. (NEDO)

Fairbanks Geothermal Energy Project Final Report

Energy Technology Data Exchange (ETDEWEB)

Karl, Bernie [CHSR,LLC Owner

2013-05-31

The primary objective for the Fairbanks Geothermal Energy Project is to provide another source of base-load renewable energy in the Fairbanks North Star Borough (FNSB). To accomplish this, Chena Hot Springs Resort (Chena) drilled a re-injection well to 2700 feet and a production well to 2500 feet. The re-injection well allows a greater flow of water to directly replace the water removed from the warmest fractures in the geothermal reservoir. The new production will provide access to warmer temperature water in greater quantities.

Natural radioactivity of geothermal water in Beijing, China

International Nuclear Information System (INIS)

Shufang Wang; Chao Ye; Jiurong Liu; Pei Lin; Kai Liu; Pei Dong; Ying Sun; Yuanzhang Liu; Liya Wang; Guifang Wang

2017-01-01

In this work, we collected 101 geothermal water samples to investigate comprehensively the radioactivity of geothermal water in Beijing. The concentrations of gross beta, 226 Ra and 222 Rn were measured and the obtained values were in the range of 0.032-7.060, 0.023-0.363 and 0.470-29.700 Bq/L, respectively. The samples with higher concentration of 222 Rn were found to be located near large faults. The effective dose of 222 Rn in the air for three cases were calculated to be greater than radiation dose limit of 1 mSv/a. (author)

Using Facilities And Potential Of Geothermal Resources In The Canakkale Province - NW Turkey

Science.gov (United States)

Deniz, Ozan; Acar Deniz, Zahide

2016-04-01

Turkey, due to its geological location, has a rich potential in point of geothermal resources. Çanakkale province is located northwestern (NW) part of Turkey and it has important geothermal fields in terms of geothermal energy potential. Geothermal resources reach to the surface both effects of past volcanic activity and extensions of fault zones associated with complex tectonic systems in the region. The aim of this study is to summarize hydrogeochemical characteristics, using facilities and potential of hot springs and spas located in the Çanakkale province. There are 13 geothermal fields in the region and the surface temperatures of hot springs are ranging between 28 centigrade degree and 175 centigrade degree. Hydrogeochemical compositions of thermal water display variable chemical compositions. Na, Ca, SO4, HCO3 and Cl are the dominant ions in these waters. Thermal waters of Tuzla and Kestanbol geothermal fields which is located the near coastal area can be noted NaCl type. Because these two geothermal waters have high TDS values, scaling problems are seen around the hot springs and pipelines. Geothermal waters in the province are meteoric origin according to oxygen-18, deuterium and tritium isotopes data. Long underground residence times of these waters and its temperatures have caused both more water - rock interaction and low tritium values. Geothermal energy is utilized in many areas in Turkey today. It is generally used for space heating, balneotherapy and electricity generation. Explorations of geothermal resources and investments in geothermal energy sector have risen rapidly in the recent years particularly in western Turkey. High-temperature geothermal fields are generally located in this region related to the Aegean Graben System and the North Anotalian Fault Zone. All geothermal power plants in Turkey are located in this region. Considering the Çanakkale province, most geothermal fields are suitable for multipurpose usage but many of them have

Geothermal space/water heating for Mammoth Lakes Village, California. Quarterly technical progress report, 13 December 1976-12 March 1977

Energy Technology Data Exchange (ETDEWEB)

Sims, A.V.; Racine, W.C.

1977-01-01

During the second three months of this feasibility study to determine the technical, economic and environmental feasibility of heating Mammoth Lakes Village, California using geothermal energy, the following work was accomplished. A saturation survey of the number and types of space and water heaters currently in use in the Village was completed. Electric energy and ambient temperature metering equipment was installed. Peak heating demand for Mammoth Lakes was estimated for the years 1985, 1990 and 2000. Buildings were selected which are considered typical of Mammoth Lakes in terms of their heating systems to be used in estimating the cost of installing hydronic heating systems in Mammoth. Block diagrams and an order of magnitude cost comparison were prepared for high-temperature and low-temperature geothermal district heating systems. Models depicting a geothermal district heating system and a geothermal-electric power plant were designed, built and delivered to ERDA in Washington. Local input to the feasibility study was obtained from representatives of the State of California Departments of Transportation and Fish and Game, US Forest Service, and Mono County Planning Department.

Potential for offshore geothermal developments using deep gas wells

Energy Technology Data Exchange (ETDEWEB)

Teodoriu, C.; Falcone, G. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). ITE

2013-08-01

The development of geothermal resources is steadily increasing as operators meet the challenge of maximising the temperature difference between production and injection wells, while minimising the wellhead temperature of the latter. At present, the minimum working wellhead temperature reported for the heat-to-electricity conversion cycles is limited to about 80 C. The cycle efficiency can be improved by reducing the injection temperature, which is the temperature at which the fluid exits the process. This paper evaluates the potential for generating electricity with a subsea geothermal plant using the difference between downhole reservoir temperature and that of the cold seawater at the mud line. The temperature in the world's oceans is relatively constant, ranging from 0 to 4 C at around 400 meters water depth. The use of these lower offshore water temperatures may help boost geothermal energy development. Deep gas resources are considered to be held within reservoirs below 4600 meters (15000 feet) and are relatively undeveloped as the risks and costs involved in drilling and producing such resources are extremely high. These deep resources have high reservoir temperatures, which offer an opportunity for geothermal exploitation if a new development concept can be formulated. In particular, the well design and reservoir development plan should consider reutilising existing well stock, including dry and plugged and abandoned wells for geothermal application once the gas field has been depleted. The major risks considered in this study include alternative uses of wells in no flow or rapid depletion situations. Reutilisation of the wells of depleted gas reservoirs will invariably lead to lower geothermal development costs compared with starting a geothermal campaign by drilling new wells. In particular, the well design and reservoir development plan should consider reutilising existing well stock, including dry and plugged and abandoned wells for geothermal

Diagenetic effect on permeabilities of geothermal sandstone reservoirs

DEFF Research Database (Denmark)

Weibel, Rikke; Olivarius, Mette; Kristensen, Lars

The Danish subsurface contains abundant sedimentary deposits, which can be utilized for geothermal heating. The Upper Triassic – Lower Jurassic continental-marine sandstones of the Gassum Formation has been utilised as a geothermal reservoir for the Thisted Geothermal Plant since 1984 extracting...... and permeability is caused by increased diagenetic changes of the sandstones due to increased burial depth and temperatures. Therefore, the highest water temperatures typically correspond with the lowest porosities and permeabilities. Especially the permeability is crucial for the performance of the geothermal......-line fractures. Continuous thin chlorite coatings results in less porosity- and permeability-reduction with burial than the general reduction with burial, unless carbonate cemented. Therefore, localities of sandstones characterized by these continuous chlorite coatings may represent fine geothermal reservoirs...

Isotope and hydrogeochemical studies of southern Jiangxi geothermal systems, China

International Nuclear Information System (INIS)

Zhou Wenbin; Li Xueli; Shi Weijun; Sun Zhanxue

1999-01-01

Southern Jiangxi is a geothermally active region, especially in Hengjing area. According to the work plan of IAEA Regional Collaboration in the Development of Geothermal Energy Resources and Environment Management through Isotope Techniques in East Asia and the Pacific (RAS-8-075), field investigation was carried out in Hengjing, southern Jiangxi Province, to demonstrate the use of isotope and geochemical techniques in low to medium temperature geothermal system. During the field investigation, 19 samples were taken from cold springs, hot springs and surface water in the area to determine their hydrochemical and gas compositions, hydrogen, oxygen, carbon and helium isotopes. The results of the study have shown that the geothermal waters in the studying region are of the same characteristics with the local meteoric water in oxygen and hydrogen isotope composition, indicating the geothermal waters are mainly derived from the local precipitation, while the gas composition and carbon and helium isotopes reveal that some gases in the geothermal waters have mantle origin. (author)

Low enthalpy geothermal for oil sands (LEGO)

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

Geothermal energy is generated by the slow decay of radioactive materials within the Earth. Geothermal energy resources include the water from hot springs used for heating; the withdrawal of high temperature steam from deep wells; and the use of stable ground or water temperatures near the Earth's surface to heat or cool buildings or in industrial processes. Heat pumps are used to transfer heat or water from the ground into buildings in winter. This paper discussed low enthalpy geothermal options for oil sands processes in order to reduce the use of natural gas and emissions from greenhouse gases (GHGs). The study was also conducted to aid in the development of a portfolio of renewable energy options for the oil and gas sector. The study estimated the costs and benefits of operating a shallow geothermal borehole cluster for meeting a portion of process heat demands for the Nexen's Albian mine. The costs and benefits of operating thermo-chillers integrated with a shallow geothermal borehole cluster for waste heat mitigation were also evaluated. The study showed that geothermal designs can be used to meet a portion of oil sands process heat and cooling demands. Mining operators may reduce carbon emissions and energy costs for process heat demands by installing closed loop borehole heat exchangers. Geothermal heat storage capacity can also be used to increase the efficiency of thermal chillers. It was concluded that pilot plant studies would contribute to a better understanding of the technology. tabs., figs.

Experimental evaluation of a non-azeotropic working fluid for geothermal heat pump system

International Nuclear Information System (INIS)

Zhao, L.

2004-01-01

Geothermal energy resources are found in many countries. A reasonable and efficient utilization of these resources has been a worldwide concern. The application of geothermal heat pump systems (GHPS) can help increase the efficiency of using geothermal energy and reduce the thermal pollution to the earth surface. However, this is only possible with a proper working fluid. In this paper, a non-azeotropic working fluid (R290/R600a/R123) is presented for a GHPS where geothermal water at 40-45 deg. C and heating network water at 70-80 deg. C serve as the low and high temperature heat sources. Experimental results show that the coefficient of performance (COP) of a GHPS using the working fluid is above 3.5 with the condensation temperature above 80 deg. C and the condensation pressure below 18 bar, while the temperature of the geothermal water is reduced from 40-46 deg. C to 31-36 deg. C

Isotopic and chemical studies of geothermal waters of Northern Areas in Pakistan

Energy Technology Data Exchange (ETDEWEB)

Dildar Hussain, S; Ahmad, M; Akram, W; Sajjad, M I [Pakistan Inst. of Nuclear Science and Technology, Islamabad (Pakistan); Gonfiantini, R [International Atomic Energy Agency, Vienna (Austria). Isotope Hydrology Section; Tasneem, M A

1995-02-01

Northern Areas is one of the major thermal fields of Pakistan with more than two dozen known hot springs having discharge temperature ranging from 35 deg. C to 94 deg. C. Isotopic and chemical techniques applied to study the geothermal fields show that thermal waters are of meteoric origin and can be classified as Na-HCO{sub 3}, Na-SO{sub 4} and mixed type on the basis of their chemical contents. At some places cooling of thermal waters seems to be due to steam separation whereas mixing with fresh cold water is prominent at the remaining sites. The temperatures estimated by isotopic and chemical geothermometers for the two major fields i.e. Tatta Pani and Murtazabad are 83-257 deg. C and 65-296 deg. C respectively. (author). 24 refs, 11 figs, 3 tabs.

Potential decline in geothermal energy generation due to rising temperatures under climate change scenarios

Science.gov (United States)

Angel, E.; Ortega, S.; Gonzalez-Duque, D.; Ruiz-Carrascal, D.

2016-12-01

Geothermal energy production depends on the difference between air temperature and the geothermal fluid temperature. The latter remains approximately constant over time, so the power generation varies according to local atmospheric conditions. Projected changes in near-surface air temperatures in the upper levels of the tropical belt are likely to exceed the projected temperature anomalies across many other latitudes, which implies that geothermal plants located in these regions may be affected, reducing their energy output. This study focuses on a hypothetical geothermal power plant, located in the headwaters of the Claro River watershed, a key high-altitude basin in Los Nevados Natural Park, on the El Ruiz-Tolima volcanic massif, in the Colombian Central Andes, a region with a known geothermal potential. Four different Atmospheric General Circulation Models where used to project temperature anomalies for the 2040-2069 prospective period. Their simulation outputs were merged in a differentially-weighted multi-model ensemble, whose weighting factors were defined according to the capability of individual models to reproduce ground truth data from a set of digital data-loggers installed in the basin since 2008 and from weather stations gathering climatic variables since the early 50s. Projected anomalies were computed for each of the Representative Concentration Pathways defined by the IPCC Fifth Assessment Report in the studied region. These climate change projections indicate that air temperatures will likely reach positive anomalies in the range +1.27 ºC to +3.47 ºC, with a mean value of +2.18 ºC. Under these conditions, the annual energy output declines roughly 1% per each degree of increase in near-surface temperature. These results must be taken into account in geothermal project evaluations in the region.

Non-electrical uses of geothermal energy

Energy Technology Data Exchange (ETDEWEB)

Barbier, E; Fanelli, M

1977-01-01

The non-electric applications of geothermal energy, with the exception of balneology, date back to the nineteenth century and have been given a new impetus by the recent oil crisis. In general, water or water-steam mixtures at temperatures between 20 and 180/sup 0/C are used for these applications. The search for geothermal fluids draws on techniques from hydrogeology, geochemistry and geophysics, the same techniques as applied to the search for cold waters, together with some specific methods connected with the underground thermal conditions. Geothermal energy is used in agriculture, aquaculture, district heating and cooling and various industrial applications. The power associated with these uses throughout the world at present can be estimated at 6200 MW and future prospects are by now promising and of definite economic interest. The environmental impact from geothermal energy is lower than that caused by conventional energy sources. Reinjection of used fluids back into the underground may, however, solve pollution problems.

Non-electrical uses of geothermal energy

Energy Technology Data Exchange (ETDEWEB)

Barbier, E; Fanelli, M

1977-01-01

The non-electric applications of geothermal energy, with the exception of balneology, date back to the nineteenth century and have been given a new impetus by the recent oil crisis. In general, water or water--steam mixtures at temperatures between 20 and 180/sup 0/C are used for these applications. The search for geothermal fluids draws on techniques from hydrogeology, geochemistry and geophysics, the same techniques as applied to the search for cold waters, together with some specific methods connected with the underground thermal conditions. Geothermal energy is used in agriculture, aquaculture, district heating and cooling, and various industrial applications. The power associated with these uses throughout the world at present can be estimated at 6200 MW and future prospects are by now promising and of definite economic interest. The environmental impact from geothermal energy is lower than that caused by conventional energy sources. Reinjection of used fluids back into the underground may, however, solve pollution problems.

Technical-economic aspects of the utilization of geothermal waters

International Nuclear Information System (INIS)

Barbier, E.

1989-01-01

A brief description is given of the physico-chemical parameters characterized a hot water geothermal reservoir and of its exploitation by means of single or coupled (doublet) wells. The technical aspects of geothermal heat to the users is then discussed, beginning with corrosion of materials caused by seven main agents: oxygen, hydrogen sulphide, carbon dioxide, ammonia, hydrogen, sulphates and chlorides. A brief mention is made of scaling due to calcium carbonate, silica and calcium sulphates. The basic components of a geothermal plant for non-electric uses are then discussed: production pumps, surface pipelines, heat exchangers, heat pumps and reinjection pumps. The advantages and disadvantages of the different equipment and materials used in the geothermal sector are also presented. A list is also given of the criteria used in the energy and economic balance of a geothermal operation. (author). 24 refs, 13 figs, 2 tabs

Renewable Energy Essentials: Geothermal

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

Geothermal energy is energy available as heat contained in or discharged from the earth's crust that can be used for generating electricity and providing direct heat for numerous applications such as: space and district heating; water heating; aquaculture; horticulture; and industrial processes. In addition, the use of energy extracted from the constant temperatures of the earth at shallow depth by means of ground source heat pumps (GSHP) is also generally referred to as geothermal energy.

Geothermal energy technology

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

Geothermal energy research and development by the Sunshine Project is subdivided into five major categories: exploration and exploitation technology, hot-water power generation technology, volcanic power generation technology, environmental conservation and multi-use technology, and equipment materials research. The programs are being carried out by various National Research Institutes, universities, and private industry. During 1976 and 1977, studies were made of the extent of resources, reservoir structure, ground water movement, and neotectonics at the Onikobe and Hachimantai geothermal fields. Studies to be performed in the near future include the use of new prospecting methods, including artificial magnetotellurics, heat balance calculation, brightspot techniques, and remote sensing, as well as laboratory studies of the physical, mechanical, and chemical properties of rock. Studies are continuing in the areas of ore formation in geothermal environments, hot-dry-rock drilling and fracturing, large scale prospecting technology, high temperature-pressure drilling muds and well cements, and arsenic removal techniques.

Estimate of Hot Dry Rock Geothermal Resource in Daqing Oilfield, Northeast China

OpenAIRE

Guangzheng Jiang; Yi Wang; Yizuo Shi; Chao Zhang; Xiaoyin Tang; Shengbiao Hu

2016-01-01

Development and utilization of deep geothermal resources, especially a hot dry rock (HDR) geothermal resource, is beneficial for both economic and environmental consideration in oilfields. This study used data from multiple sources to assess the geothermal energy resource in the Daqing Oilfield. The temperature logs in boreholes (both shallow water wells and deep boreholes) and the drilling stem test temperature were used to create isothermal maps in depths. Upon the temperature field and the...

Aerated drilling cutting transport analysis in geothermal well

Science.gov (United States)

Wakhyudin, Aris; Setiawan, Deni; Dwi Marjuan, Oscar

2017-12-01

Aeratad drilling widely used for geothermal drilling especially when drilled into predicted production zone. Aerated drilling give better performance on preventing lost circulation problem, improving rate of penetration, and avoiding drilling fluid invasion to productive zone. While well is drilled, cutting is produced and should be carried to surface by drilling fluid. Hole problem, especially pipe sticking will occur while the cutting is not lifted properly to surface. The problem will effect on drilling schedule; non-productive time finally result more cost to be spent. Geothermal formation has different characteristic comparing oil and gas formation. Geothermal mainly has igneous rock while oil and gas mostly sedimentary rock. In same depth, formation pressure in geothermal well commonly lower than oil and gas well while formation temperature geothermal well is higher. While aerated drilling is applied in geothermal well, Igneous rock density has higher density than sedimentary rock and aerated drilling fluid is lighter than water based mud hence minimum velocity requirement to transport cutting is larger than in oil/gas well drilling. Temperature and pressure also has impact on drilling fluid (aerated) density. High temperature in geothermal well decrease drilling fluid density hence the effect of pressure and temperature also considered. In this paper, Aerated drilling cutting transport performance on geothermal well will be analysed due to different rock and drilling fluid density. Additionally, temperature and pressure effect on drilling fluid density also presented to merge.

Life Cycle Water Consumption and Water Resource Assessment for Utility-Scale Geothermal Systems: An In-Depth Analysis of Historical and Forthcoming EGS Projects

Energy Technology Data Exchange (ETDEWEB)

Clark, Corrie E. [Argonne National Lab. (ANL), Argonne, IL (United States); Harto, Christopher B. [Argonne National Lab. (ANL), Argonne, IL (United States); Schroeder, Jenna N. [Argonne National Lab. (ANL), Argonne, IL (United States); Martino, Louis E. [Argonne National Lab. (ANL), Argonne, IL (United States); Horner, Robert M. [Argonne National Lab. (ANL), Argonne, IL (United States)

2013-08-01

This report is the third in a series of reports sponsored by the U.S. Department of Energy Geothermal Technologies Program in which a range of water-related issues surrounding geothermal power production are evaluated. The first report made an initial attempt at quantifying the life cycle fresh water requirements of geothermal power-generating systems and explored operational and environmental concerns related to the geochemical composition of geothermal fluids. The initial analysis of life cycle fresh water consumption of geothermal power-generating systems identified that operational water requirements consumed the vast majority of water across the life cycle. However, it relied upon limited operational water consumption data and did not account for belowground operational losses for enhanced geothermal systems (EGSs). A second report presented an initial assessment of fresh water demand for future growth in utility-scale geothermal power generation. The current analysis builds upon this work to improve life cycle fresh water consumption estimates and incorporates regional water availability into the resource assessment to improve the identification of areas where future growth in geothermal electricity generation may encounter water challenges. This report is divided into nine chapters. Chapter 1 gives the background of the project and its purpose, which is to assess the water consumption of geothermal technologies and identify areas where water availability may present a challenge to utility-scale geothermal development. Water consumption refers to the water that is withdrawn from a resource such as a river, lake, or nongeothermal aquifer that is not returned to that resource. The geothermal electricity generation technologies evaluated in this study include conventional hydrothermal flash and binary systems, as well as EGSs that rely on engineering a productive reservoir where heat exists, but where water availability or permeability may be limited. Chapter 2

Hydrogeochemical Characteristics and Geothermometry Applications of Thermal Waters in Coastal Xinzhou and Shenzao Geothermal Fields, Guangdong, China

Directory of Open Access Journals (Sweden)

Xiao Wang

2018-01-01

Full Text Available Two separate groups of geothermal waters have been identified in the coastal region of Guangdong, China. One is Xinzhou thermal water of regional groundwater flow system in a granite batholith and the other is thermal water derived from shallow coastal aquifers in Shenzao geothermal field, characterized by high salinity. The hydrochemical characteristics of the thermal waters were examined and characterized as Na-Cl and Ca-Na-Cl types, which are very similar to that of seawater. The hydrochemical evolution is revealed by analyzing the correlations of components versus Cl and their relative changes for different water samples, reflecting different extents of water-rock interactions and clear mixing trends with seawaters. Nevertheless, isotopic data indicate that thermal waters are all of the meteoric origins. Isotopic data also allowed determination of different recharge elevations and presentation of different mixing proportions of seawater with thermal waters. The reservoir temperatures were estimated by chemical geothermometries and validated by fluid-mineral equilibrium calculations. The most reliable estimates of reservoir temperature lie in the range of 148–162°C for Xinzhou and the range of 135–144°C for Shenzao thermal waters, based on the retrograde and prograde solubilities of anhydrite and chalcedony. Finally, a schematic cross-sectional fault-hydrology conceptual model was proposed.

Geothermal source potential and utilization for alcohol production

Energy Technology Data Exchange (ETDEWEB)

Austin, J.C.

1981-11-01

A study was conducted to assess the technical and economic feasibility of using a potential geothermal source to drive a fuel grade alcohol plant. Test data from the well at the site indicated that the water temperature at approximately 8500 feet should approach 275/sup 0/F. However, no flow data was available, and so the volume of hot water that can be expected from a well at this site is unknown. Using the available data, numerous fuel alcohol production processes and various heat utilization schemes were investigated to determine the most cost effective system for using the geothermal resource. The study found the direct application of hot water for alcohol production based on atmospheric processes using low pressure steam to be most cost effective. The geothermal flow rates were determined for various sizes of alcohol production facility using 275/sup 0/F water, 235/sup 0/F maximum processing temperature, 31,000 and 53,000 Btu per gallon energy requirements, and appropriate process approach temperatures. It was determined that a 3 million gpy alcohol plant is the largest facility that can practically be powered by the flow from one large geothermal well. An order-of-magnitude cost estimate was prepared, operating costs were calculated, the economic feasibility of the propsed project was examined, and a sensitivity analysis was performed.

Numerical investigation on the implications of spring temperature and discharge rate with respect to the geothermal background in a fault zone

Science.gov (United States)

Jiang, Zhenjiao; Xu, Tianfu; Mariethoz, Gregoire

2018-04-01

Geothermal springs are some of the most obvious indicators of the existence of high-temperature geothermal resources in the subsurface. However, geothermal springs can also occur in areas of low average subsurface temperatures, which makes it difficult to assess exploitable zones. To address this problem, this study quantitatively analyzes the conditions associated with the formation of geothermal springs in fault zones, and numerically investigates the implications that outflow temperature and discharge rate from geothermal springs have on the geothermal background in the subsurface. It is concluded that the temperature of geothermal springs in fault zones is mainly controlled by the recharge rate from the country rock and the hydraulic conductivity in the fault damage zone. Importantly, the topography of the fault trace on the land surface plays an important role in determining the thermal temperature. In fault zones with a permeability higher than 1 mD and a lateral recharge rate from the country rock higher than 1 m3/day, convection plays a dominant role in the heat transport rather than thermal conduction. The geothermal springs do not necessarily occur in the place having an abnormal geothermal background (with the temperature at certain depth exceeding the temperature inferred by the global average continental geothermal gradient of 30 °C/km). Assuming a constant temperature (90 °C here, to represent a normal geothermal background in the subsurface at a depth of 3,000 m), the conditions required for the occurrence of geothermal springs were quantitatively determined.

Stable isotope studies of some low enthalpy geothermal systems in Kenya

Science.gov (United States)

Tole, Mwakio P.

Oxygen and hydrogen isotope compositions of some low enthalpy geothermal systems in Kenya have been determined. Plots on δ 18O versus δD diagrams show that the compositions do not deviate appreciably from local meteoric water values. This would indicate that local meteoric waters are heated at depth and rise to the surface without much interaction with the country rocks. This is interpreted to be the case for the geothermal systems at Majimoto and Narosura, which have salinities of less than 350 ppm TDS and calculated reservoir temperatures of less than 110°C. The geothermal systems at Kapedo and Homa mountain which have high salinities (> 2 000 ppm TDS) and relatively higher calculated reservoir temperatures (> 150° C) are interpreted to have been operating for long periods of time, such that the rocks through which the present day geothermal waters are circulating have attained isotopic equilibrium with local meteoric waters.

Geothermal investigations in Slovenia

Directory of Open Access Journals (Sweden)

Danilo Ravnik

1991-12-01

Full Text Available The paper presents the methodology and the results of geothermal investigations, based on seventy-two boreholes in the territory of the Republic of Slovenia.The data of fundamental geothermal quantities: formation temperature, thermal conductivity, and radiogenic heat production of rocks as well as surface heat flow density are stored in a computerized data base. Their synthesis is given in the map of formation temperatures at 1000 m depth and in the map of surface heat flow density. In both maps the thermal difference between the Pannonian basin in theeastern and the Dinarides in the western part of Slovenia is clearly expressed.However, in the boundary area between these two tectonic units, for a distance of about 100 km in SW-NE direction, elevated horizontal gradients of formation temperature as well as heat flow density are evident. A small positive thermal anomaly in the Ljubljana depression is conspicuous.The low-temperature geothermal resources in Slovenia such as thermalsprings and thermal water from boreholes, are estimated to have a flow rate of 1120 kg/s, corresponding to the ideal total heat production of 144 MWt. In the geothermally promising areas amounting to 3200 km2 the rate of accessible resource base (ARB down to the depth of 3 km has been assessed to about 8.5 x lO 20» J.

Research on accumulating the harmful elements in geothermal water with aquatic plants

Energy Technology Data Exchange (ETDEWEB)

Xing, Bingbing; Guo, Licong; Peng, Yongqing [Institute of Energy Sources (China); The Institute of Biology (China))

1988-11-10

As a result of component analyses for geothermal water, environmental pollution potentialities with use of geothermal water were generally recognized with high mineral material and high content of F{sup -}in North China. Although injection methods are effective to eliminate the environment pollution of geothermal fluid, the technique and cost of injection are not practical at present yet for the technical level and financial capacity of China and other developing countries. Through the comparison of physical, chemical and biological methods, the biological method possesses low cost and great disposed quantity. After making the test for accumulating harmful elements in geothermal water with aquatic plants to find suitable one, nine kinds of aquatic plants, which can accumulate elements of Cl{sup -}, Na{sup +} and F{sup -}, were selected for further tests. As a test result, the aquatic plants which could comprehensively accumulate Na{sup +}, Cl{sup -} and F{sup -} were Ceratophyllum demersum, Mymphoides pettatum and Spirodela polyrrhiza, the aquatic plant which could comprehensively accumulate Na{sup +} and Cl{sup -} was Alternanthera philoxenoids, and the aquatic plant which could accumulate F{sup -} was Lemna minor. These aquatic plants were considered as the optimized plants for purifying geothermal water. 4 refs., 5 tabs.

Characterizations of geothermal springs along the Moxi deep fault in the western Sichuan plateau, China

Science.gov (United States)

Qi, Jihong; Xu, Mo; An, Chengjiao; Wu, Mingliang; Zhang, Yunhui; Li, Xiao; Zhang, Qiang; Lu, Guoping

2017-02-01

Abundant geothermal springs occur along the Moxi fault located in western Sichuan Province (the eastern edge of the Qinghai-Tibet plateau), highlighted by geothermal water outflow with an unusually high temperature of 218 °C at 21.5 MPa from a 2010-m borehole in Laoyulin, Kangding. Earthquake activity occurs relatively more frequently in the region and is considered to be related to the strong hydrothermal activity. Geothermal waters hosted by a deep fault may provide evidence regarding the deep underground; their aqueous chemistry and isotopic information can indicate the mechanism of thermal springs. Cyclical variations of geothermal water outflows are thought to work under the effect of solid earth tides and can contribute to understanding conditions and processes in underground geo-environments. This paper studies the origin and variations of the geothermal spring group controlled by the Moxi fault and discusses conditions in the deep ground. Flow variation monitoring of a series of parameters was performed to study the geothermal responses to solid tides. Geothermal reservoir temperatures are evaluated with Na-K-Mg data. The abundant sulfite content, dissolved oxygen (DO) and oxidation-reduction potential (ORP) data are discussed to study the oxidation-reduction states. Strontium isotopes are used to trace the water source. The results demonstrate that geothermal water could flow quickly through the Moxi fault the depth of the geothermal reservoir influences the thermal reservoir temperature, where supercritical hot water is mixed with circulating groundwater and can reach 380 °C. To the southward along the fault, the circulation of geothermal waters becomes shallower, and the waters may have reacted with metamorphic rock to some extent. Our results provide a conceptual deep heat source model for geothermal flow and the reservoir characteristics of the Moxi fault and indicate that the faulting may well connect the deep heat source to shallower depths. The

Stream hydraulics and temperature determine the metabolism of geothermal Icelandic streams

Directory of Open Access Journals (Sweden)

Demars B. O.L.

2011-07-01

Full Text Available Stream ecosystem metabolism plays a critical role in planetary biogeochemical cycling. Stream benthic habitat complexity and the available surface area for microbes relative to the free-flowing water volume are thought to be important determinants of ecosystem metabolism. Unfortunately, the engineered deepening and straightening of streams for drainage purposes could compromise stream natural services. Stream channel complexity may be quantitatively expressed with hydraulic parameters such as water transient storage, storage residence time, and water spiralling length. The temperature dependence of whole stream ecosystem respiration (ER, gross primary productivity (GPP and net ecosystem production (NEP = GPP − ER has recently been evaluated with a “natural experiment” in Icelandic geothermal streams along a 5–25 °C temperature gradient. There remained, however, a substantial amount of unexplained variability in the statistical models, which may be explained by hydraulic parameters found to be unrelated to temperature. We also specifically tested the additional and predicted synergistic effects of water transient storage and temperature on ER, using novel, more accurate, methods. Both ER and GPP were highly related to water transient storage (or water spiralling length but not to the storage residence time. While there was an additional effect of water transient storage and temperature on ER (r2 = 0.57; P = 0.015, GPP was more related to water transient storage than temperature. The predicted synergistic effect could not be confirmed, most likely due to data limitation. Our interpretation, based on causal statistical modelling, is that the metabolic balance of streams (NEP was primarily determined by the temperature dependence of respiration. Further field and experimental work is required to test the predicted synergistic effect on ER. Meanwhile, since higher metabolic activities allow for higher pollutant degradation or uptake

Rock geochemistry related to mineralization processes in geothermal areas

Science.gov (United States)

Kausar, A. Al; Indarto, S.; Setiawan, I.

2018-02-01

Abundant geothermal systems in Indonesia suggest high heat and mass transfer associated with recent or paleovolcanic arcs. In the active geothermal system, the upflow of mixed fluid between late stage hydrothermal and meteoric water might contain mass of minerals associated with epithermal mineralisation process as exemplified at Lihir gold mine in Papua New Guinea. In Indonesia, there is a lack of study related to the precious metals occurrence within active geothermal area. Therefore, in this paper, we investigate the possibility of mineralization process in active geothermal area of Guci, Central Java by using geochemical analysis. There are a lot of conducted geochemical analysis of water, soil and gas by mapping the temperature, pH, Hg and CO2 distribution, and estimating subsurface temperature based on geothermometry approach. Then we also apply rock geochemistry to find minerals that indicate the presence of mineralization. The result from selected geothermal area shows the presence of pyrite and chalcopyrite minerals on the laharic breccias at Kali Putih, Sudikampir. Mineralization is formed within host rock and the veins are associated with gold polymetallic mineralization.

Magnetotelluric-Geochemistry Investigations of Blawan Geothermal Field, East Java, Indonesia

Directory of Open Access Journals (Sweden)

Sukir Maryanto

2017-06-01

Full Text Available An integrated magnetotelluric (MT and geochemical study of the Blawan geothermal field has been performed. The character of the hot springs, the reservoir temperature, and geothermal reserve potential of Blawan geothermal field are assessed. MT measurements, with 250 m up to 1200 m spacings, were made at 19 sites, and 6 locations at the Blawan hot springs have been sampled for geochemical survey. The results of 2D modelling indicated that the geothermal system in the research area consisted of a cap rock zone (≤32 Ω•m, reservoir zone (>32 – ≤512 Ω•m, and heat source zone (>512 Ω•m, and also identified faults. The characteristics of the hot spring water were identified through analyzing the major and minor elements. A ternary diagram (Cl-SO4-HCO3 showed that the Blawan hot springs consist of bicarbonate water (at locations of AP-01, AP-02, AP-03 and chloride water (at locations of AP-04, AP-05, and AP-06, with a reservoir temperature of approximately 90 °C based on the Na–K–Ca geothermometer results. An estimate of the geothermal energy using the volumetric method, gave a total geothermal reserve potential of 1.823 MWe.

Laser-fluorescence determination of trace uranium in hot spring water, geothermal water and tap water in Xi'an Lishan region

International Nuclear Information System (INIS)

Ma Wenyan; Zhou Chunlin; Han Feng; Di Yuming

2002-01-01

Using the Laser-Fluorescence technique, an investigation was made, adopting the standard mix method, on trace uranium concentrations in hot spring water and geothermal water from Lishan region, and in tap water from some major cities in Shanxi province. Totally 40 samples from 27 sites were investigated. Measurement showed that the tap water contains around 10 -6 g/L of uranium, whose concentrations in both hot spring water and geothermal water are 10 -5 g/L. Most of samples are at normal radioactive background level, some higher contents were determined in a few samples

Temperature measurement of geothermal wells by optical fiber sensor; Hikari fiber sensor wo mochiita chinetsusei no ondo bunpu keisoku

Energy Technology Data Exchange (ETDEWEB)

Matsushima, N; Sakaguchi, K [Geological Survey of Japan, Tsukuba (Japan)

1996-10-01

Experiments of temperature measurement were conducted in high temperature and high pressure geothermal wells using optical fiber sensor. A temperature measurement system using optical fiber sensor was applied to geothermal wells. Working availability was confirmed under the condition up to the depth of 1,750 m and the temperature of 240 centigrade. Observed values agreed well with those observed by the conventional temperature logging. Durability of the optical fiber sensor was also sufficient. The maximum standard deviations of measured values were 1.3 centigrade at the depth of 1,750 m at 195 centigrade for the loop-type sensor, and 3.7 centigrade at the depth of 365 m at about 200 centigrade for the single-end sensor. Although the accuracy was inferior to the conventional measurement using a thermo couple, it was enough to be applied to usual temperature logging. Furthermore, for this system, the temperature profile in the whole well can be monitored, simultaneously. Through the experiments, the detailed successive change of temperature profile accompanied with the water injection can be clearly illustrated. 3 refs., 7 figs.

Future directions and cycles for electricity production from geothermal resources

International Nuclear Information System (INIS)

Michaelides, Efstathios E.

2016-01-01

Graphical abstract: 25% more power may be produced using binary-flashing geothermal cycles. - Highlights: • Power from geothermal power plants is continuously available and “dispatchable.” • The next generation of geothermal will include more binary plants. • Lower temperature geothermal resources will be utilized in the future. • Dry rock resources may produce a high fraction of electricity in several countries. - Abstract: Geothermal power production is economically competitive and capable to produce a high percentage of the electric power demand in several countries. The currently operating geothermal power plants utilize water from an aquifer at relatively higher temperatures and produce power using dry steam, flashing or binary cycles. A glance at the map of the global geothermal resources proves that there is a multitude of sites, where the aquifer temperature is lower. There are also many geothermal resources where a high geothermal gradient exists in the absence of an aquifer. It becomes apparent that the next generation of geothermal power plants will utilize more of the lower-temperature aquifer resources or the dry resources. For such power plants to be economically competitive, modified or new cycles with higher efficiencies must be used. This paper presents two methods to increase the efficiency of the currently used geothermal cycles. The first uses a binary-flashing system to reduce the overall entropy production, thus, producing more electric power from the resource. The second describes a heat extraction system to be used with dry hot-rock resources.

Preliminary analysis of geothermal aspects of Brazilian thermal spring

International Nuclear Information System (INIS)

Hurter, S.J.; Hamza, V.M.

1982-01-01

Information on more than 400 geothermal springs in Brazil has been assembled. On the basis of the data colected the temperatures at the maximum depths of circulation of spring waters are calculated using the quality of silica dissolved in water. For some thermal springs temperatures are calculated on the basis of silica determination carrried out by us. Applying linear relations between silica temperature and geothermal flux the average depths of water circulation in the Parana Basin and the Brazilian folded belts surrounding the San Francisco craton are calculated. The radioactivity of the water, derived mainly from the dissolved radon can be correlated with the temperature of the spring. An inverse correlation, as was observed for thermal springs of Pocos de Caldas, can be used to calculate the ascent velocity of thermal waters, where as, a positive correlations could be interpreted as due to the mixing of thermal with surface waters. (Author) [pt

DMRC studies geothermal energy options

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-03-01

The Deep Mining Research Consortium (DMRC) is an industry-led research consortium that includes Vale Inco, Xstrata, Rio Tinto, Goldcorp, Agnico-Eagle, Barrick Gold, CANMET and the City of Sudbury. This article reported on the application of geothermal energy technologies to cool deep mine workings and use the heat from underground to produce energy to heat surface buildings. Researchers at the University of British Columbia's Centre for Environmental Research in Minerals, Metals and Materials have proposed the use of heat pumps and water-to-air heat exchangers at depth to chill mine workings. The heat pumps would act as refrigerators, taking heat from one area and moving it elsewhere. The purpose would be to extract heat from naturally occurring ground water and pass the chilled water through a heat exchanger to cool the air. The heated water would then be pumped to surface and used to heat surface facilities. The technology is well suited for using geothermal energy from decommissioned mines for district heating. The technology has been successfully used in Spring Hill, Nova Scotia, where geothermal energy from a decommissioned coal mine is used to heat an industrial park. A feasibility study is also underway for the city of Yellowknife in the Northwest Territories to produce up to 10 megawatts of heat from the Con Gold Mine, enough energy to heat half of Yellowknife. Geothermal energy can also be used to generate electricity, particularly in the Pacific Rim where underground temperatures are higher and closer to surface. In Sudbury Ontario, the enhanced geothermal systems technology would require two holes drilled to a depth of four kilometers. The ground between the two holes should be fractured to create an underground geothermal circuit. Geothermal energy does not produce any greenhouse gases or chemical wastes. 1 fig.

High Temperature Perforating System for Geothermal Applications

Energy Technology Data Exchange (ETDEWEB)

Smart, Moises E. [Schlumberger Technology Corporation, Sugar Land, TX (United States)

2017-02-28

The objective of this project is to develop a perforating system consisting of all the explosive components and hardware, capable of reliable performance in high temperatures geothermal wells (>200 ºC). In this light we will focused on engineering development of these components, characterization of the explosive raw powder and developing the internal infrastructure to increase the production of the explosive from laboratory scale to industrial scale.

Heat Exchangers for Utilization of the Heat of High-Temperature Geothermal Brines

Science.gov (United States)

Alkhasov, A. B.; Alkhasova, D. A.

2018-03-01

The basic component of two-circuit geothermal systems is the heat exchanger. When used in geothermal power systems, conventional shell-and-tube and plate heat exchangers cause problems related to the cleaning of the latter from salt-deposition and corrosion products. Their lifetime does not exceed, as a rule, 1 year. To utilize the heat of high-temperature geothermal brines, a heat exchanger of the "tube-in-tube" type is proposed. A heat exchanger of this design has been operated for several years in Ternair geothermal steam field; in this heat exchanger, the thermal potential of the saline thermal water is transferred to the fresh water of the secondary circuit of the heating system for apartment houses. The reduction in the weight and size characteristics of the heat exchangers is a topical problem that can be solved with the help of heat transfer enhancers. To enhance the heat transfer process in the heat exchanger, longitudinal ribbing of the heat exchange surface is proposed. The increase in the heat exchange surface from the heat carrier side by ribbing results in an increase in the amount of the heat transferred from the heating agent. The heat exchanger is easy to manufacture and is assembled out of components comprised of two concentrically positioned tubes of a definite length, 3-6 m, serially connected with each other. The method for calculation of the impact of the number and the size of the longitudinal ribs on the heat transfer in the well heat exchanger is presented and a criterion for the selection of the optimal number and design parameters of the ribs is formulated. To prevent the corrosion and salt deposition in the heat exchanger, the use of an effective OEDFK (oxyethylidenediphosphonic acid) agent is proposed. This agent has a long-lasting corrosion-inhibiting and antiscaling effect, which is explained by the formation of a strongly adhesive chelate layer difficult to wash off the surface. The passivating OEDFK layer is restored by periodical

Desalination of Impaired Water Using Geothermal Energy

Energy Technology Data Exchange (ETDEWEB)

Turchi, Craig S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Akar, Sertac [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cath, Tzahi [Colorado School of Mines; Vanneste, Johan [Colorado School of Mines; Gustafson, Emily [Colorado School of Mines

2017-10-04

Membrane distillation (MD) and nanofiltration (NF) are explored as a means to provide high quality water for on-site use at the Tuscarora geothermal power plant in northern Nevada. The plant uses a wet cooling tower, but decreasing flow from the wells providing makeup water necessitates exploration for alternative water or alternative cooling sources. Scenarios are explored to extend cooling water by (1) extracting fresh water from the geothermal brine, (2) upgrading the makeup-water quality to allow for increased cycles of concentration in the cooling tower, or (3) recovering water from the cooling tower blowdown. The preliminary cost analysis indicates that applying NF to extract water from the injection brine is the most attractive option of the scenarios examined. This approach may be useful for other plants as well. The estimated cost for the NF treatment of the injection brine ranges from $0.63/m3 to $0.45/m3 and provides a reduction in the current makeup well flows of 35% to 71%. Savings from the reduction in makeup well pumping and chemical treatment do not fully offset the estimated cost of the proposed treatment systems; the site will have to weigh the cost of these water treatment options versus alternatives in light of the diminishing flows from the existing cooling-water wells. Testing is planned to quantify the performance of the proposed NF and MD technologies and help refine the estimated system costs.

The Hengill geothermal area, Iceland: Variation of temperature gradients deduced from the maximum depth of seismogenesis

Science.gov (United States)

Foulger, G. R.

1995-04-01

Given a uniform lithology and strain rate and a full seismic data set, the maximum depth of earthquakes may be viewed to a first order as an isotherm. These conditions are approached at the Hengill geothermal area S. Iceland, a dominantly basaltic area. The likely strain rate calculated from thermal and tectonic considerations is 10 -15 s -1, and temperature measurements from four drill sites within the area indicate average, near-surface geothermal gradients of up to 150 °C km -1 throughout the upper 2 km. The temperature at which seismic failure ceases for the strain rates likely at the Hengill geothermal area is determined by analogy with oceanic crust, and is about 650 ± 50 °C. The topographies of the top and bottom of the seismogenic layer were mapped using 617 earthquakes located highly accurately by performing a simultaneous inversion for three-dimensional structure and hypocentral parameters. The thickness of the seismogenic layer is roughly constant and about 3 km. A shallow, aseismic, low-velocity volume within the spreading plate boundary that crosses the area occurs above the top of the seismogenic layer and is interpreted as an isolated body of partial melt. The base of the seismogenic layer has a maximum depth of about 6.5 km beneath the spreading axis and deepens to about 7 km beneath a transform zone in the south of the area. Beneath the high-temperature part of the geothermal area, the maximum depth of earthquakes may be as shallow as 4 km. The geothermal gradient below drilling depths in various parts of the area ranges from 84 ± 9 °Ckm -1 within the low-temperature geothermal area of the transform zone to 138 ± 15 °Ckm -1 below the centre of the high-temperature geothermal area. Shallow maximum depths of earthquakes and therefore high average geothermal gradients tend to correlate with the intensity of the geothermal area and not with the location of the currently active spreading axis.

Origin, evolution and geothermometry of the thermal waters in the Gölemezli Geothermal Field, Denizli Basin (SW Anatolia, Turkey)

Science.gov (United States)

Alçiçek, Hülya; Bülbül, Ali; Brogi, Andrea; Liotta, Domenico; Ruggieri, Giovanni; Capezzuoli, Enrico; Meccheri, Marco; Yavuzer, İbrahim; Alçiçek, Mehmet Cihat

2018-01-01

The Gölemezli Geothermal Field (GGF) is one of the best known geothermal fields in western Anatolia (Turkey). The exploited fluids are of meteoric origin, mixed with deep magmatic fluids, which interacted with the metamorphic rocks of the Menderes Massif. The geothermal fluids are channeled along Quaternary faults belonging to the main normal faults system delimiting the northern side of the Denizli Basin and their associated transfer zones. In this study, hydrochemical and isotopic analyses of the thermal and cold waters allow us to determine water-rock interactions, fluid paths and mixing processes. Two groups of thermal waters have been distinguished: (i) Group 1A, comprising Na-SO4 type and Ca-SO4 type and (ii) Group 1B, only consisting Ca-HCO3 type waters. Differently, two groups were recognized in the cold waters: (i) Group 2A, corresponding to Ca-HCO3 type and (ii) Group 2B, including Mg-HCO3 type. Their geochemical characteristics indicate interactions with the Paleozoic metamorphic rocks of the Menderes Massif and with the Neogene lacustrine sedimentary rocks. Dissolution of host rock and ion-exchange reactions modify thermal water composition in the reservoir of the GGF. High correlation in some ionic ratios and high concentrations of some minor elements suggest an enhanced water-rock interaction. None of the thermal waters has been reached a complete chemical re-equilibrium, possibly as a result of mixing with cold water during their pathways. Geothermal reservoir temperatures are calculated in the range of 130-210°C for the Gölemezli field. Very negative δ18O and δ2H isotopic ratios are respectively between -8.37 and -8.13‰ and -61.09 and -59.34‰ for the SO4-rich thermal waters, and ca. - 8.40 and -8.32‰ and - 57.80 and -57.41‰ for the HCO3-rich thermal waters. Low tritium (link existing between fractures and fluid convection in the extensional settings. In this view, the GGF is a very good example of geothermal field associated to active

Enhancement of existing geothermal resource utilization by cascading to intensive aquaculture

Energy Technology Data Exchange (ETDEWEB)

Zachritz, W.H. II; Polka, R.; Schoenmackers, R.

1995-12-04

Aquaculture, the farming and husbandry of freshwater and marine organisms, is the newest and fastest growing US agricultural sector. In New Mexico, low winter temperatures and limited freshwater sources narrow culture production possibilities; however, it has long been recognized that the state has abundant supplies of both saline and geothermal ground waters. The purpose of this project was to demonstrate the achievable energy savings and value enhancement of the byproduct geothermal energy by cascading fluids for the production of commercial aquaculture species. Specifically the project involved evaluating the heating systems performance in terms of heating budget for the geothermal assist, determine the total quantity of water used for culture and heating, amount of geothermal byproduct heat extracted, and ability of the system to maintain culture water temperatures during critical heating periods of the year. In addition, an analysis was conducted to determine the compatibility of this new system with existing greenhouse heating requirements.

Technologies for the Comprehensive Exploitation of the Geothermal Resources of the North Caucasus Region

Science.gov (United States)

Alkhasov, A. B.

2018-03-01

Technology for the integrated development of low-temperature geothermal resources using the thermal and water potentials for various purposes is proposed. The heat of the thermal waters is utilized in a low-temperature district heating system and for heating the water in a hot water supply system. The water cooled in heat exchangers enters a chemical treatment system where it is conditioned into potable water quality and then forwarded to the household and potable water supply system. Efficient technologies for removal of arsenic and organic contaminants from the water have been developed. For the uninterrupted supply of the consumers with power, the technologies that use two and more types of renewable energy sources (RESs) have the best prospects. Technology for processing organic waste using the geothermal energy has been proposed. According to this technology, the geothermal water is divided into two flows, one of which is delivered to a biomass conversion system and the other is directed to a geothermal steam-gas power plant (GSGP). The wastewater arrives at the pump station from which it is pumped back into the bed. Upon drying, the biogas from the conversion system is delivered into the combustion chamber of a gas-turbine plant (GTP). The heat of the turbine exhaust gases is used in the GSGP to evaporate and reheat the low-boiling working medium. The working medium is heated in the GSGP to the evaporation temperature using the heat of the thermal water. High-temperature geothermal brines are the most promising for the comprehensive processing. According to the proposed technology, the heat energy of the brines is utilized to generate the electric power at a binary geothermal power station; the electric power is then used to extract the dissolved chemical components from the rest of the brine. The comprehensive utilization of high-temperature brines of the East-Precaucasian Artesian Basin will allow to completely satisfy the demand of Russia for lithium

ADDRESSING ENVIRONMENTAL CHALLENGES UNDER COMPREHENSIVE UTILIZATION OF GEOTHERMAL SALINE WATER RESOURCES IN THE NORTHERN DAGESTAN

Directory of Open Access Journals (Sweden)

A. Sh. Ramazanov

2016-01-01

Full Text Available Aim. The aim of the study is to develop technologies for processing geothermal brine produced with the extraction of oil as well as to solve environmental problems in the region.Methods. In order to determine the chemical composition and radioactivity of the geothermal water and solid samples, we used atomic absorption and gamma spectrometry. Evaluation of the effectiveness of the technology was made on the basis of experimental studies.Results. In the geothermal water, eight radionuclides were recognized and quantified with the activity of 87 ± 5 Bq / dm3. For the processing of this water to produce lithium carbonate and other components we propose a technological scheme, which provides a step of water purification from radio-nuclides. As a result of aeration and alkalinization, we can observe deactivation and purification of the geothermal water from mechanical impurities, iron ions, hydrogen carbonates and organic substances. Water treatment allows recovering lithium carbonate, magnesite caustic powder and salt from geothermal water. The mother liquors produced during manufacturing operations meet the requirements for the water suitable for waterflooding of oil reservoirs and can be injected for maintaining the reservoir pressure of the deposits.Conclusion. The implementation of the proposed processing technology of mineralized geothermal water produced with the extraction of oil in the Northern Dagestan will contribute to extend the life of the oil fields and improve the environmental problems. It will also allow import substitution in Russia for lithium carbonate and edible salt.

Geothermal Frontier: Penetrate a boundary between hydrothermal convection and heat conduction zones to create 'Beyond Brittle Geothermal Reservoir'

Science.gov (United States)

Tsuchiya, N.; Asanuma, H.; Sakaguchi, K.; Okamoto, A.; Hirano, N.; Watanabe, N.; Kizaki, A.

2013-12-01

EGS has been highlightened as a most promising method of geothermal development recently because of applicability to sites which have been considered to be unsuitable for geothermal development. Meanwhile, some critical problems have been experimentally identified, such as low recovery of injected water, difficulties to establish universal design/development methodology, and occurrence of large induced seismicity. Future geothermal target is supercritical and superheated geothermal fluids in and around ductile rock bodies under high temperatures. Ductile regime which is estimated beyond brittle zone is target region for future geothermal development due to high enthalpy fluids and relatively weak water-rock interaction. It is very difficult to determine exact depth of Brittle-Ductile boundary due to strong dependence of temperature (geotherm) and strain rate, however, ductile zone is considered to be developed above 400C and below 3 km in geothermal fields in Tohoku District. Hydrothermal experiments associated with additional advanced technology will be conducting to understand ';Beyond brittle World' and to develop deeper and hotter geothermal reservoir. We propose a new concept of the engineered geothermal development where reservoirs are created in ductile basement, expecting the following advantages: (a)simpler design and control the reservoir, (b)nearly full recovery of injected water, (c)sustainable production, (d)cost reduction by development of relatively shallower ductile zone in compression tectonic zones, (e)large quantity of energy extraction from widely distributed ductile zones, (f)establishment of universal and conceptual design/development methodology, and (g) suppression of felt earthquakes from/around the reservoirs. In ductile regime, Mesh-like fracture cloud has great potential for heat extraction between injection and production wells in spite of single and simple mega-fracture. Based on field observation and high performance hydrothermal

The tracer function of isotope composition and deuterium excess parameter of water bodies on prospecting for geothermal water: taking the prospecting for geothermal water in Sanjianshui, Sichuan for example

International Nuclear Information System (INIS)

Yang Bo; Yin Guan

2003-01-01

Based on the isotope composition features of water bodies in Sanjiashui area, this paper use the theory of deuterium excess parameter (d) to discuss and cause of formulation, recharge source, removed patch, detained time and dynamics feature on ground water. These discussed problems have far-reaching meaning on evaluating the size of geothermal water, exploited potential of thermal spring and find new thermal spring in neighboring area. We analyze the relation of d and tritium content (T) on different water bodies in Sanjianshui area and draw some conclusions. Firstly, all water bodies in Sanjianshui origin from precipitation. Secondly, precipitation of northwest mountain area that have long removed patch and long detained time is the recharge resource of groundwater in basin. In addition, we demonstrate the possibility of existence of geothermal water in several positions of Sanjianshui area. (authors)

NEDO Forum 2000. Geothermal technology development session (new development of geothermal energy); Chinetsu gijutsu kaihatsu session. Chinetsu energy no shintenkai

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-09-01

The following themes were presented at this session: (1) geothermal development in the future, (2) the current status of geothermal development and utilization, (3) surveys on the promotion of geothermal development, and (4) verification and investigation on geothermal exploration technologies, development of hot water utilizing power generation plants, and international cooperation on geothermal development and utilization. In Item 2, report was made on the current status of geothermal power plants in Japan and their future development targets, long-term overview of geothermal development, measures and budgets to achieve the targets of geothermal development. In Item 3, it is reported that out of 48 areas completed of the survey (including the new promotion surveyed areas), the areas possible of steam power generation and confirmed of temperatures higher than 200 degrees C are 30 areas, and the areas possible of binary power generation (using down hole pumps) and small to medium scale power generation, confirmed of temperatures of 100 to 200 degrees C are 13 areas. In Item 4, reports were made on the reservoir bed variation exploring method, surveys on deep geothermal resources, a 10-MW demonstration plant, a system to detect well bottom information during excavation of geothermal wells, a technology to collect deep geothermal resources, and a hot-rock using power generation system. In Item 5, geothermal exploration in remote islands in the eastern part of Indonesia, and the IEA cooperation projects were reported. (NEDO)

Resource investigation of low- and moderate-temperature geothermal areas in Paso Robles, California

Energy Technology Data Exchange (ETDEWEB)

Campion, L.F.; Chapman, R.H.; Chase, G.W.; Youngs, L.G.

1983-01-01

Ninety-eight geothermal wells and springs were identified and plotted, and a geologic map and cross sections were compiled. Detailed geophysical, geochemical, and geological surveys were conducted. The geological and geophysical work delineated the basement highs and trough-like depressions that can exercise control on the occurrence of the thermal waters. The Rinconada fault was also evident. Cross sections drawn from oil well logs show the sediments conforming against these basement highs and filling the depressions. It is along the locations where the sediments meet the basement highs that three natural warm springs in the area occur. Deep circulation of meteoric waters along faults seems to be a reasonable source for the warm water. The Santa Margarita, Pancho Rico, and Paso Robles Formations would be the first permeable zones that abut the faults through which water would enter. Temperatures and interpretation of well logs indicate the warmest aquifer at the base of the Paso Robles Formation. Warm water may be entering higher up in the section, but mixing with water from cooler zones seems to be evident. Geothermometry indicates reservoir temperatures could be as high as 91/sup 0/C (196/sup 0/F).

Experimental investigation of ice and snow melting process on pavement utilizing geothermal tail water

International Nuclear Information System (INIS)

Wang Huajun; Zhao Jun; Chen Zhihao

2008-01-01

Road ice and snow melting based on low temperature geothermal tail water is of significance to realize energy cascading utilization. A small scale ice and snow melting system is built in this work. Experiments of dynamic melting processes of crushed ice, solid ice, artificial snow and natural snow are conducted on concrete pavement. The results show that the melting process of ice and snow includes three phases: a starting period, a linear period and an accelerated period. The critical value of the snow free area ratio between the linear period and the accelerated period is about 0.6. The physical properties of ice and snow, linked with ambient conditions, have an obvious effect on the melting process. The difference of melting velocity and melting time between ice and snow is compared. To reduce energy consumption, the formation of ice on roads should be avoided if possible. The idling process is an effective pathway to improve the performance of melting systems. It is feasible to utilize geothermal tail water of about 40 deg. C for melting ice and snow on winter roads, and it is unnecessary to keep too high fluid temperatures during the practical design and applications. Besides, with the exception of solid ice, the density and porosity of snow and ice tend to be decreasing and increasing, respectively, as the ambient temperature decreases

Geothermal energy

Energy Technology Data Exchange (ETDEWEB)

Gasparovic, N

1962-07-01

Live steam, transformed steam, and steam produced by expansion flashing are outlined with respect to their use in the production of electricity. The capacity, pressure, and temperature of a steam must be determined empirically by exploratory drilling. These factors are dependent on time and on the extent of nearby drilling-activity. Particulars of geothermal-steam power-plants such as steam dryness, hot-water flashing, condensation, gas extraction, and corrosion are discussed in detail. All available data (as per 1962) concerning the costs of operation and construction of geothermal power plants are tabulated. For space-heating purposes, two basic systems are utilized. When little corrosion or precipitation is expected, an open system is used, otherwise, closed systems are necessary. The space-heating system of Reykjavik, Iceland is cited as an example. A brief description of industrial applications of geothermal energy, such as the extraction of NaCl, D/sub 2/O, or boric acid, is provided. Thirty-two references are given.

Comparison of the microbial communities of hot springs waters and the microbial biofilms in the acidic geothermal area of Copahue (Neuquén, Argentina).

Science.gov (United States)

Urbieta, María Sofía; González-Toril, Elena; Bazán, Ángeles Aguilera; Giaveno, María Alejandra; Donati, Edgardo

2015-03-01

Copahue is a natural geothermal field (Neuquén province, Argentina) dominated by the Copahue volcano. As a consequence of the sustained volcanic activity, Copahue presents many acidic pools, hot springs and solfataras with different temperature and pH conditions that influence their microbial diversity. The occurrence of microbial biofilms was observed on the surrounding rocks and the borders of the ponds, where water movements and thermal activity are less intense. Microbial biofilms are particular ecological niches within geothermal environments; they present different geochemical conditions from that found in the water of the ponds and hot springs which is reflected in different microbial community structure. The aim of this study is to compare microbial community diversity in the water of ponds and hot springs and in microbial biofilms in the Copahue geothermal field, with particular emphasis on Cyanobacteria and other photosynthetic species that have not been detected before in Copahue. In this study, we report the presence of Cyanobacteria, Chloroflexi and chloroplasts of eukaryotes in the microbial biofilms not detected in the water of the ponds. On the other hand, acidophilic bacteria, the predominant species in the water of moderate temperature ponds, are almost absent in the microbial biofilms in spite of having in some cases similar temperature conditions. Species affiliated with Sulfolobales in the Archaea domain are the predominant microorganism in high temperature ponds and were also detected in the microbial biofilms.

Use of Geothermal Energy for Aquaculture Purposes - Phase III

Energy Technology Data Exchange (ETDEWEB)

Johnson, W C; Smith, K C

1981-09-01

This project, financed by the Pacific Northwest Regional Commission (PNRC), was designed to provide information to evaluate the best methods to use for intensive aquaculture of freshwater prawns, Macrobrachium rosenbergii, using geothermal energy. The freshwater prawn is a tropical organism and is native to southeast Asia. Earlier projects at Oregon Institute of Technology have shown the feasibility of culturing this aquatic animal in geothermal water. This phase of the project was designed to investigate intensive culture of this animal as well as the advantages of growing rainbow trout, ornamental tropical fin fish, and mosquito fish, Gambusia affnis, for vector control using geothermal energy. The research data collected on the prawns was obtained from the stocking and sampling of two 0.2- ha (half-acre) ponds constructed as a part of the project. The ponds are equipped with recording monitors for temperature and flow. The geothermal energy used is the geothermal effluent from the Oregon Institute of Technology heating system. This water is of potable quality and ranges in temperature from 50 to 70oC. The geothermal water used in the ponds is controlled at 27oC, ± 2oC, by using thermostats and solenoid valves. A small building next to the ponds contains facilities for hatching larvae prawns and tanks for growing post-larvae prawns. The hatchery facility makes the project self-sustaining. The hatchery was obtained as part of an earlier PNRC project.

Selection of working fluids for a novel low-temperature geothermally-powered ORC based cogeneration system

International Nuclear Information System (INIS)

Guo, T.; Wang, H.X.; Zhang, S.J.

2011-01-01

Highlights: → Performances of a novel cogeneration system using low-temperature geothermal sources under disturbance conditions were investigated. → It aimed at identifying appropriate fluids yielding high PPR and QQR values. → Fluids group presenting higher normal boiling point values showed averagely 7.7% higher PPR with a larger variation than QQR values under disturbance conditions. → Smaller T P value, higher η t value, higher geothermal source parameters and lower heating supply parameters led to higher PPR values but lower QQR values. -- Abstract: A novel cogeneration system driven by low-temperature geothermal sources was investigated in this study. This system consists of a low-temperature geothermally-powered organic Rankine cycle (ORC) subsystem, an intermediate heat exchanger and a commercial R134a-based heat pump subsystem. The main purpose is to identify appropriate fluids which may yield high PPR (the ratio of power produced by the power generation subsystem to power consumed by the heat pump subsystem) value and QQR (the ratio of heat supplied to the user to heat produced by the geothermal source) value. Performances of the novel cogeneration system under disturbance conditions have also been studied. Results indicate that fluids group presenting higher normal boiling point values shows averagely 7.7% higher PPR values and R236ea and R245ca outstand among the group. ΔT P (pinch temperature difference in heat exchangers) and η t (turbine efficiency) values play more important roles on the variation of PPR values. QQR values change slightly with various ΔT P , η t and η rp (refrigerant pump efficiency) values while the variation range is larger under various geothermal source and heating supply parameters. Smaller ΔT P value, higher η t value, higher geothermal source parameters and lower heating supply parameters lead to higher PPR values but lower QQR values.

Major hydrogeochemical processes in the two reservoirs of the Yangbajing geothermal field, Tibet, China

Science.gov (United States)

Guo, Qinghai; Wang, Yanxin; Liu, Wei

2007-10-01

The Yangbajing geothermal field with the highest reservoir temperature in China is located about 90 km northwest to Lhasa City, capital of Tibet, where high temperature geothermal fluids occur both in shallow and deep reservoirs. The geophysical survey by the INDEPTH (International Deep Profiling of Tibet and the Himalayas) project group proved the existence of magmatic heat source at Yangbajing. In the study area, the hydrochemistry of cold surface waters and groundwaters and that of thermal groundwaters from both reservoirs are distinctively different. However, analysis of the relationship between enthalpy values and Cl concentrations of cold groundwaters and geothermal fluids indicates that the geothermal fluids from the shallow reservoir were formed as a result of mixing of cold groundwaters with geothermal fluids from the deep reservoir. In other words, the geothermal fluids from the deep reservoir flowed upwards into the shallow reservoir where it was diluted by the shallow cold groundwaters to form the shallow geothermal fluids with much lower temperature. A binary mixing model with two endmembers (the cold groundwaters and the deep geothermal fluids) was proposed and the mixing ratios for the geothermal fluid from each shallow well were estimated. Using the mixing ratios, the concentrations of some constituents in shallow geothermal fluids, such as As, B, SiO 2, SO 42- and F, were calculated and their differences with the actual concentrations were estimated. The results show that the differences between estimated and actual concentrations of As and B are small (the average absolute values being only 1.9% and 7.9%, respectively), whereas those of SiO 2, SO 42- and F are much bigger, indicating that other hydrogeochemical processes are responsible for the concentrations of these constituents. It is postulated that SiO 2 precipitation due to water temperature decrease, H 2S oxidation and ion exchange between OH - in geothermal waters and exchangeable F - in

Oxygen isotope studies of the Salton Sea geothermal field

International Nuclear Information System (INIS)

Olson, E.R.

1978-01-01

Interbedded shales and sandstones were drilled to a depth of 1588 metres in Sinclair Number Four Well, Salton Sea Geothermal Field. Bottom hole temperatures are approximately 290 0 C. The oxygen dels of hydrothermal and detrital calcite have a systematic relationship at any depth in the geothermal reservoir. Typical values are: vein calcite, +6 0 / 00 ; calcite in white sandstone, +10 0 / 00 ; calcite in dark gray shale, +11 0 / 00 ; calcite in light gray shale, +17 0 / 00 ; calcite in red-brown shale, +20 0 / 00 . This succession represents decreasing water-rock interaction that is also indicated by the clay mineralogy of the shales. Permeability has a marked effect on the equilibration of water and rocks at any given temperature. Original differences in permeability have resulted in partial preservation of original detrital sedimentary compositions. The fluids in the Salton Sea Geothermal Field are probabaly partially evaporated Colorado River water, and their oxygen del values vary as much as 4 0 / 00 throughout the field. Truesdell's (1974) data suggest that dissolved salts may make the water oxygen activity del as much as 6 0 / 00 greater than the concentration del in the geothermal reservoir. Such an uncertainty is a serious impediment to precise isotope geothermometry in this system.(auth.)

Low Temperature Geothermal Play Fairway Analysis For The Appalachian Basin: Phase 1 Revised Report November 18, 2016

Energy Technology Data Exchange (ETDEWEB)

Jordan, Teresa E. [Cornell Univ., Ithaca, NY (United States); Richards, Maria C. [Southern Methodist Univ., Dallas, TX (United States); Horowitz, Franklin G. [Cornell Univ., Ithaca, NY (United States); Camp, Erin [Cornell Univ., Ithaca, NY (United States); Smith, Jared D. [Cornell Univ., Ithaca, NY (United States); Whealton, Calvin A. [Cornell Univ., Ithaca, NY (United States); Stedinger, Jery R. [Cornell Univ., Ithaca, NY (United States); Hornbach, Matthew J. [Southern Methodist Univ., Dallas, TX (United States); Frone, Zachary S. [Southern Methodist Univ., Dallas, TX (United States); Tester, Jefferson W. [Cornell Univ., Ithaca, NY (United States); Anderson, Brian [West Virginia Univ., Morgantown, WV (United States); Welcker, Kelydra [West Virginia Univ., Morgantown, WV (United States); Chickering Pace, Catherine [Southern Methodist Univ., Dallas, TX (United States); He, Xiaoning [West Virginia Univ., Morgantown, WV (United States); Magnani, Maria Beatrice [Southern Methodist Univ., Dallas, TX (United States); Bolat, Rahmi [Southern Methodist Univ., Dallas, TX (United States)

2016-11-18

Pennsylvania, for which the available geological data are insufficient to fully analyze the geological risks but yet the population is high. First, to assess the spatial variation in the depth to which one would need to drill to obtain geothermal temperatures that are useful to a future project, the project used bottom-hole temperature data from Appalachian Basin oil and gas exploration. These bottom hole temperature data are abundant but of low quality. Second, the project examined the potential for sufficient water flow rates through rocks to harvest heat from a geothermal well field, considering only natural reservoirs. This analysis provides a very incomplete picture of spatial variability of natural reservoirs because the oil and gas reservoir data lack key properties and are spatially biased toward those locations with profitable amounts of hydrocarbons in the rock pore spaces. Third, in light of the fact that earthquake activity has been induced in several states by subsurface work related to the oil and gas industry, this project examined the potential for similar activity in the Appalachian Basin. Acknowledging that data for such a task are insufficient, we utilized what was available: records of seismic activity, regional estimates of the orientations of stress in the rocks, and locations and orientations of zones of lateral change in rock properties at depths down to several kilometers below Earth’s surface. With these data, we created a first approximation of spatially variable risks for induced earthquakes. Because no data existed with which to test the reliability of these methods, the results have a high degree of uncertainty. Fourth, we examined the spatial variability of the above-the-ground factors that contribute to the economical viability of projects to tap low-temperature geothermal resources for direct-use. We worked principally with population density as a regionally known variable that would impact the cost of district heating. The resulting maps

High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems

Energy Technology Data Exchange (ETDEWEB)

Turnquist, Norman [GE Global Research, Munchen (Germany); Qi, Xuele [GE Global Research, Munchen (Germany); Raminosoa, Tsarafidy [GE Global Research, Munchen (Germany); Salas, Ken [GE Global Research, Munchen (Germany); Samudrala, Omprakash [GE Global Research, Munchen (Germany); Shah, Manoj [GE Global Research, Munchen (Germany); Van Dam, Jeremy [GE Global Research, Munchen (Germany); Yin, Weijun [GE Global Research, Munchen (Germany); Zia, Jalal [GE Global Research, Munchen (Germany)

2013-12-20

This report summarizes the progress made during the April 01, 2010 – December 30, 2013 period under Cooperative Agreement DE-EE0002752 for the U.S. Department of Energy entitled “High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems.” The overall objective of this program is to advance the technology for well fluids lifting systems to meet the foreseeable pressure, temperature, and longevity needs of the Enhanced Geothermal Systems (EGS) industry for the coming ten years. In this program, lifting system requirements for EGS wells were established via consultation with industry experts and site visits. A number of artificial lift technologies were evaluated with regard to their applicability to EGS applications; it was determined that a system based on electric submersible pump (ESP) technology was best suited to EGS. Technical barriers were identified and a component-level technology development program was undertaken to address each barrier, with the most challenging being the development of a power-dense, small diameter motor that can operate reliably in a 300°C environment for up to three years. Some of the targeted individual component technologies include permanent magnet motor construction, high-temperature insulation, dielectrics, bearings, seals, thrust washers, and pump impellers/diffusers. Advances were also made in thermal management of electric motors. In addition to the overall system design for a full-scale EGS application, a subscale prototype was designed and fabricated. Like the full-scale design, the subscale prototype features a novel “flow-through-the-bore” permanent magnet electric motor that combines the use of high temperature materials with an internal cooling scheme that limits peak internal temperatures to <330°C. While the full-scale high-volume multi-stage pump is designed to lift up to 80 kg/s of process water, the subscale prototype is based on a production design that can pump 20 kg/s and has been modified

PROSPECTS OF GEOTHERMAL RESOURCES DEVELOPMENT FOR EAST CISCAUCASIA

Directory of Open Access Journals (Sweden)

A. B. Alkhasov

2013-01-01

Full Text Available Abstract. Work subject. Aim. The Northern Caucasus is one of the prospective regions for development of geothermal energy.The hydrogeothermal resources of the only East Ciscaucasian Artesian basin are estimated up to 10000 MW of heat and 1000 MW of electric power. For their large-scale development it is necessary to built wells of big diameter and high flow rate involving huge capital investments. Reconstruction of idle wells for production of thermal water will allow to reduce capital investments for building of geothermal power installations. In the East Ciscaucasian Artesian basin there are a lot of promising areas with idle wells which can be converted for production of thermal water. The purpose of work is substantiation possibility of efficient development of geothermal resources of the Northern Caucasus region using idle oil and gas wells.Methods. The schematic diagram is submitted for binary geothermal power plant (GPP with use of idle gas-oil wells where the primary heat carrier in a loop of geothermal circulation system is used for heating and evaporation of the low-boiling working agent circulating in a secondary contour of steam-power unit. Calculations are carried out for selection of the optimum parameters of geothermal circulation system for obtaining the maximum useful power of GPP. The thermodynamic analysis of low-boiling working agents is made. Development of medial enthalpy thermal waters in the combined geothermal-steam-gas power installations is offered where exhaust gases of gas-turbine installation are used for evaporation and overheat of the working agent circulating in a contour of GPP. Heating of the working agent in GPP up to the temperature of evaporation is carried out by thermal water.Results. The possibility of efficient development of geothermal resources of the Northern Caucasus region by construction of binary geothermal power plants using idle oil and gas wells is substantiated. The capacities and the basic

Study of Shallow Low-Enthalpy Geothermal Resources Using Integrated Geophysical Methods

Science.gov (United States)

De Giorgi, Lara; Leucci, Giovanni

2015-02-01

The paper is focused on low enthalpy geothermal exploration performed in south Italy and provides an integrated presentation of geological, hydrogeological, and geophysical surveys carried out in the area of municipality of Lecce. Geological and hydrogeological models were performed using the stratigraphical data from 51 wells. A ground-water flow (direction and velocity) model was obtained. Using the same wells data, the ground-water annual temperature was modeled. Furthermore, the ground surface temperature records from ten meteorological stations were studied. This allowed us to obtain a model related to the variations of the temperature at different depths in the subsoil. Integrated geophysical surveys were carried out in order to explore the low-enthalpy geothermal fluids and to evaluate the results of the model. Electrical resistivity tomography (ERT) and self-potential (SP) methods were used. The results obtained upon integrating the geophysical data with the models show a low-enthalpy geothermal resource constituted by a shallow ground-water system.

Geochemical features of the geothermal fluids from the Mapamyum non-volcanic geothermal system (Western Tibet, China)

Science.gov (United States)

Wang, Peng; Chen, Xiaohong; Shen, Licheng; Wu, Kunyu; Huang, Mingzhi; Xiao, Qiong

2016-06-01

Mapamyum geothermal field (MGF) in western Tibet is one of largest geothermal areas characterized by the occurrence of hydrothermal explosions on the Tibetan Plateau. The geochemical properties of hydrothermal water in the MGF system were investigated to trace the origin of the solutes and to determine the equilibrium temperatures of the feeding reservoir. The study results show that the geochemistry of hydrothermal waters in the MGF system is mainly of the Na-HCO3 type. The chemical components of hydrothermal waters are mainly derived from the minerals in the host rocks (e.g., K-feldspar, albite, Ca-montmorillonite, and Mg-montmorillonite). The hydrothermal waters are slightly supersaturated or undersaturated with respect to aragonite, calcite, dolomite, chalcedony and quartz (saturation indices close to 0), but are highly undersaturated with respect to gypsum and anhydrite (saturation indices < 0). Mixing models and Na-K-Mg ternary diagrams show that strong mixing between cold meteoric water and deeply-seated thermal fluids occurred during the upward flowing process. δD and δ18O data confirm that the meteoric water acts as the water source of the geothermal waters. An 220 °C equilibrated reservoir temperature of hydrothermal spring waters was calculated via both the Na-K-Mg ternary diagrams and the cationic chemical geothermometers. The logpCO2 of hydrothermal waters in the MGF system ranges from - 2.59 to - 0.57 and δ13C of the total dissolved inorganic carbon ranges from - 5.53‰ to - 0.94‰, suggesting that the carrier CO2 in hydrothermal water are mainly of a magmatic or metamorphic CO2 origin.

First geothermal pilot power plant in Hungary

Directory of Open Access Journals (Sweden)

Tóth Anikó

2007-01-01

Full Text Available The Hungarian petroleum industry has always participated in the utilization of favourable geothermal conditions in the country. Most of the Hungarian geothermal wells were drilled by the MOL Ltd. as CH prospect holes. Accordingly, the field of geothermics belonged to the petroleum engineering, although marginally. It was therefore a surprise to hear of the decision of MOL Ltd. to build a geothermal power plant of about 2-5 MW. The tender was published in 2004.The site selected for the geothermal project is near the western border of an Hungarian oilfield, close to the Slovenian border. The location of the planned geothermal power plant was chosen after an analysis of suitable wells owned by the MOL Rt. The decision was made on the bases of different reservoir data. The existence of a reservoir of the necessary size, temperature, permeability, productivity and the water chemistry data was proved. The wells provide an enough information to understand the character of the reservoir and will be the production wells used by the planned power plant.The depth of the wells is about 2930 - 3200 m. The Triassic formation is reached at around 2851 m. The production and the reinjection wells are planned. The primary objective of the evaluation is to further learn the nature of the geothermal system. First a one-day discharge test is carried out. If this short-term test is successful, a six-months long-term discharge test will follow. The first period of the test is a transient phenomenon. Within the well test, the wellhead pressure, the flow rate, the outflowing water temperature, the dynamic fluid level, and the chemical components will be measured. The heat transfer around the bore-hole is influenced by the flow rate and the time. For the right appreciation of the measured data, it is very important to analyse the heat transfer processes around the bore-hole. The obtained data from the experiments must be also fitted into the framework of a mathematical

Very low energy geothermics

International Nuclear Information System (INIS)

Anon.

1995-01-01

Very low energy geothermics correspond to temperatures below 30 C and has been developed to cover heating and cooling needs of recent individual houses or tertiary industries using heat pumps and low depth aquifers (<100 m). Geothermal heat pumps industry has made great strides in European Northern countries, China, Japan and the United States of America. Geothermal heat pumps are less energy consuming than air heat pumps and require less cooling fluid and maintenance. The Aquapac procedure has been developed in France in 1983 by the AFME (French Energy Control Agency), EdF and the BRGM (Geologic and Mining Research Office) to encourage the use of geothermal heat pump for domestic and sanitary water heating and to make a survey of low-depth aquifers in the whole french territory. The decay of energy costs that started in 1986 has led to a loss of interest for the Aquapac procedure, even in the tertiary industries for which the air-conditioning demand is growing up. (J.S.). 1 tab

Chemical composition of the thermomineral waters of Josanicka Banja spa as an origin indicator, balneological valorization and geothermal potential

Directory of Open Access Journals (Sweden)

Milenić Dejan R.

2015-01-01

Full Text Available The chemical composition of the groundwater is directly dependent on the geological structure, hydrogeological and hydrochemical characteristics and as such it represents an output result of all the factors and processes which take place in the environment within which they were formed. The chemical composition of thermomineral waters often represents a crucial factor in determining the origin, balneological valorization and geothermal potential of the resources. This work presents the analysis of origin, belneological valorization and geothermal potential of Josanicka Banja spa, on the basis of the results gained through making the analyisis of chemical contents of the thermomineral waters which occur in the area. The ratio of concentrations of specific chemical components in the thermomineral waters of Josanicka Banja has served as the basic tool for ascertaining the origin of these waters. On the basis of the analysis of the main anion-cation and gas compositions as well as the contents of specific micro-components, a balneological valorization of these resources has been carried out. Apart from that this work also presents the calculation of the expected temperatures in the primary geothermal reservoir, which was carried out on the basis of the results of chemical analysis of thermomineral waters that occur in the area. Geothermal potential of about 4 MWt and significant contents of balneologically active components of the chemical composition of these waters, open up a possibility for their multi-purpose use, which is also presented in the work. [Projekat Ministarstva nauke Republike Srbije, br. TR 33053

The Parisian basin, birthplace of geothermics

International Nuclear Information System (INIS)

Jeanson, E.

1995-01-01

The exploitation of low energy geothermics in France is mainly localized in the Parisian Basin. About 40 geothermal plants are established in urbanized areas for heating and sanitary hot water supplies and also for air conditioning. Each plant can supply about 2500 to 5000 lodgings of collective buildings. Excluding drilling costs, urban investments can reach 70% of the total operating cost. Most of the exploitations draw the geothermal fluids from the Dogger reservoir located at a 1500-2000 m depth using double-well technique. Water temperature is about 60 to 85 C and solutes (salts and sulfides) represent 15 to 35 g/l. The deeper Albian and Neocomian drinking water reservoirs are exceptionally used due to their strategic nature. The corrosion problems and the age of the installations are the principal problems of the existing installations but the operating costs remain competitive with other energy sources. (J.S.). 3 figs., 9 photos

Demonstration of a Variable Phase Turbine Power System for Low Temperature Geothermal Resources

Energy Technology Data Exchange (ETDEWEB)

Hays, Lance G

2014-07-07

A variable phase turbine assembly will be designed and manufactured having a turbine, operable with transcritical, two-phase or vapor flow, and a generator – on the same shaft supported by process lubricated bearings. The assembly will be hermetically sealed and the generator cooled by the refrigerant. A compact plate-fin heat exchanger or tube and shell heat exchanger will be used to transfer heat from the geothermal fluid to the refrigerant. The demonstration turbine will be operated separately with two-phase flow and with vapor flow to demonstrate performance and applicability to the entire range of low temperature geothermal resources. The vapor leaving the turbine is condensed in a plate-fin refrigerant condenser. The heat exchanger, variable phase turbine assembly and condenser are all mounted on single skids to enable factory assembly and checkout and minimize installation costs. The system will be demonstrated using low temperature (237F) well flow from an existing large geothermal field. The net power generated, 1 megawatt, will be fed into the existing power system at the demonstration site. The system will demonstrate reliable generation of inexpensive power from low temperature resources. The system will be designed for mass manufacturing and factory assembly and should cost less than $1,200/kWe installed, when manufactured in large quantities. The estimated cost of power for 300F resources is predicted to be less than 5 cents/kWh. This should enable a substantial increase in power generated from low temperature geothermal resources.

Geothermal energy and its application opportunities in Serbia

Directory of Open Access Journals (Sweden)

Andrić Nenad M.

2015-01-01

Full Text Available Geothermal energy is accumulated heat in the fluid and rock masses in the Earth 's crust. The natural decay of radioactive elements (uranium, thorium and potassium in rocks produces heat energy. The simplest use of geothermal energy for heating is by heat pump. Geothermal energy can be used for production of electricity. It uses hot water and steam from the earth to run the generator. Serbia has significant potential for geothermal energy. The total amount of accumulated heat in geothermal resources in a depth of 3 km is two times higher than the equivalent thermal energy that could be obtained by burning all types of coal from all their sites in Serbia! The total abundance of geothermal resources in Serbia is 4000 l/s. Abundance of wells in Vojvodina is 10-20 l/s, and the temperature is from 40 to 60°C. Exploitation of thermal waters in Mačva could cause heating of following cities: Bogatić, Šabac, Sremska Mitrovica and Loznica, with a total population of 150.000 people. The richest hydrogeothermal resources are in Mačva, Vranje and Jošanička Banja. Using heat pumps, geothermal water can be exploited on the entire territory of Serbia! Although large producer, Serbia is importing food, ie., fruits and vegetables. With the construction of greenhouses, which will be heated with geothermal energy, Serbia can become an exporting country.

Geomagnetic Survey to Explore High-Temperature Geothermal System in Blawan-Ijen, East Java, Indonesia

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Daud Yunus

2018-01-01

Full Text Available Ijen geothermal area is high-temperature geothermal system located in Bondowoso regency, East Java. It is categorized as caldera-hosted geothermal system which is covered by quaternary andesitic volcanic rocks with steep topography at the surrounding. Several surface thermal manifestations are found, such as altered rocks near Mt. Kukusan and a group of Blawan hotsprings in the northern part of the caldera. Geomagnetic survey was conducted at 72 stations which is distributed inside the caldera to delineate the existence of hydrothermal activity. Magnetic anomaly was obtained by reducing total magnetic measured on the field by IGRF and diurnal variation. Reduction to pole (RTP method was applied with geomagnetic inclination of about -32°. In general, the result shows that high magnetic anomaly is distributed at the boundary of study area, while low magnetic anomaly is observed in the centre. The low anomaly indicates demagnetized rock that probably caused by hydrothermal activity. It has a good correlation with surface alteration observed close to Mt. Kukusan as well as high temperature reservoir drilled in the centre of caldera. Accordingly, the low magnetic anomaly also presents the possibility of geothermal reservoir in Ijen geothermal area.

Geomagnetic Survey to Explore High-Temperature Geothermal System in Blawan-Ijen, East Java, Indonesia

Science.gov (United States)

Daud, Yunus; Rosid, Syamsu; Fahmi, Fikri; Yunus, Faris Maulana; Muflihendri, Reza

2018-02-01

Ijen geothermal area is high-temperature geothermal system located in Bondowoso regency, East Java. It is categorized as caldera-hosted geothermal system which is covered by quaternary andesitic volcanic rocks with steep topography at the surrounding. Several surface thermal manifestations are found, such as altered rocks near Mt. Kukusan and a group of Blawan hotsprings in the northern part of the caldera. Geomagnetic survey was conducted at 72 stations which is distributed inside the caldera to delineate the existence of hydrothermal activity. Magnetic anomaly was obtained by reducing total magnetic measured on the field by IGRF and diurnal variation. Reduction to pole (RTP) method was applied with geomagnetic inclination of about -32°. In general, the result shows that high magnetic anomaly is distributed at the boundary of study area, while low magnetic anomaly is observed in the centre. The low anomaly indicates demagnetized rock that probably caused by hydrothermal activity. It has a good correlation with surface alteration observed close to Mt. Kukusan as well as high temperature reservoir drilled in the centre of caldera. Accordingly, the low magnetic anomaly also presents the possibility of geothermal reservoir in Ijen geothermal area.

Water information bulletin No. 30 geothermal investigations in Idaho

Energy Technology Data Exchange (ETDEWEB)

Mitchell, J.C.; Johnson, L.L.; Anderson, J.E.; Spencer, S.G.; Sullivan, J.F.

1980-06-01

There are 899 thermal water occurrences known in Idaho, including 258 springs and 641 wells having temperatures ranging from 20 to 93/sup 0/C. Fifty-one cities or towns in Idaho containing 30% of the state's population are within 5 km of known geothermal springs or wells. These include several of Idaho's major cities such as Lewiston, Caldwell, Nampa, Boise, Twin Falls, Pocatello, and Idaho Falls. Fourteen sites appear to have subsurface temperatures of 140/sup 0/C or higher according to the several chemical geothermometers applied to thermal water discharges. These include Weiser, Big Creek, White Licks, Vulcan, Roystone, Bonneville, Crane Creek, Cove Creek, Indian Creek, and Deer Creek hot springs, and Raft River, Preston, and Magic Reservoir areas. These sites could be industrial sites, but several are in remote areas away from major transportation and, therefore, would probably be best utilized for electrical power generation using the binary cycle or Magma Max process. Present uses range from space heating to power generation. Six areas are known where commercial greenhouse operations are conducted for growing cut and potted flowers and vegetables. Space heating is substantial in only two places (Boise and Ketchum) although numerous individuals scattered throughout the state make use of thermal water for space heating and private swimming facilities. There are 22 operating resorts using thermal water and two commercial warm-water fish-rearing operations.

Towards a de-carbonized energy system in North-Eastern Morocco: Prospective Geothermal Resource

OpenAIRE

Rimi, Abdelkrim; Zarhloule, Yassine; Barkaoui, Alae Eddine; Correia, António; Carneiro, Júlio; Verdoya, Massimo; Lucazeau, Francis

2012-01-01

Geothermal data has been indicating promising potentialities in the north-eastern Morocco. This paper presents new temperature data, recently recorded in water boreholes located in the Berkane and Oujda areas. Generally, the observed temperature gradients are rather high. One hole near Berkane, revealed an average geothermal gradient of more than 110 °C/km at depths greater than 300 m. This result confirms the geothermal gradient estimated in a mining borehole located about 30 km west of the ...

STATIC{sub T}EMP: a useful computer code for calculating static formation temperatures in geothermal wells

Energy Technology Data Exchange (ETDEWEB)

Santoyo, E. [Universidad Nacional Autonoma de Mexico, Centro de Investigacion en Energia, Temixco (Mexico); Garcia, A.; Santoyo, S. [Unidad Geotermia, Inst. de Investigaciones Electricas, Temixco (Mexico); Espinosa, G. [Universidad Autonoma Metropolitana, Co. Vicentina (Mexico); Hernandez, I. [ITESM, Centro de Sistemas de Manufactura, Monterrey (Mexico)

2000-07-01

The development and application of the computer code STATIC{sub T}EMP, a useful tool for calculating static formation temperatures from actual bottomhole temperature data logged in geothermal wells is described. STATIC{sub T}EMP is based on five analytical methods which are the most frequently used in the geothermal industry. Conductive and convective heat flow models (radial, spherical/radial and cylindrical/radial) were selected. The computer code is a useful tool that can be reliably used in situ to determine static formation temperatures before or during the completion stages of geothermal wells (drilling and cementing). Shut-in time and bottomhole temperature measurements logged during well completion activities are required as input data. Output results can include up to seven computations of the static formation temperature by each wellbore temperature data set analysed. STATIC{sub T}EMP was written in Fortran-77 Microsoft language for MS-DOS environment using structured programming techniques. It runs on most IBM compatible personal computers. The source code and its computational architecture as well as the input and output files are described in detail. Validation and application examples on the use of this computer code with wellbore temperature data (obtained from specialised literature) and with actual bottomhole temperature data (taken from completion operations of some geothermal wells) are also presented. (Author)

Geothermal surveys in the oceanic volcanic island of Mauritius

Science.gov (United States)

Verdoya, Massimo; Chiozzi, Paolo; Pasqua, Claudio

2017-04-01

Oceanic island chains are generally characterised by young volcanic systems that are predominately composed of basaltic lavas and related magmatic products. Although hot springs are occasionally present, the pervasive, massive, recent outpourings of basaltic lavas are the primary manifestation of the existence of geothermal resources. These islands may have, in principle, significant potential for the exploitation of geothermal energy. In this paper, we present results of recent investigations aimed at the evaluation of geothermal resources of the island of Mauritius, that is the emerging portion of a huge submarine, aseismic, volcanic plateau extending in the SW part of the Indian Ocean. The plateau is related to a long-lived hotspot track, whose present-day expression is the active volcano of La Réunion Island, located about 200 km SW of Mauritius. The island does not show at present any volcanic activity, but magmatism is quite recent as it dates from 7.8 to 0.03 Myr. Geochemical data from water samples collected from boreholes do not indicate the presence of mature water, i.e. circulating in high-temperature geothermal reservoirs, and argue for short-term water-rock interaction in shallow hydrogeological circuits. However, this cannot rule out that a deep magmatic heat source, hydraulically insulated from shallow aquifers, may occur. To evaluate the geothermal gradient, a 270-m-deep hole was thus drilled in the island central portion, in which the most recent volcanic activity (0.03 Myr) took place. Temperature-depth profiles, recorded after complete thermal equilibration, revealed a thermal gradient of 40 mK/m. Attempts of extracting additional thermal information were also made by measuring the temperature in a 170-m-deep deep water hole, no longer used. The results were consistent with the gradient hole, i.e. pointing to a weak or null deep-seated thermal anomaly beneath Mauritius and low geothermal potential. The deep thermal process (mantle plume) invoked

Great Western Malting Company geothermal project, Pocatello, Idaho. Final report

Energy Technology Data Exchange (ETDEWEB)

Christensen, N.T.; McGeen, M.A.; Corlett, D.F.; Urmston, R.

1981-12-23

The Great Western Malting Company recently constructed a barley malting facility in Pocatello, Idaho, designed to produce 6.0 million bushels per year of brewing malt. This facility uses natural gas to supply the energy for germination and kilning processes. The escalating cost of natural gas has prompted the company to look at alternate and more economical sources of energy. Trans Energy Systems has investigated the viabiity of using geothermal energy at the new barley processing plant. Preliminary investigations show that a geothermal resource probably exists, and payback on the installation of a system to utilize the resource will occur in under 2 years. The Great Western Malting plant site has geological characteristics which are similar to areas where productive geothermal wells have been established. Geological investigations indicate that resource water temperatures will be in the 150 to 200/sup 0/F range. Geothermal energy of this quality will supply 30 to 98% of the heating requirements currently supplied by natural gas for this malting plant. Trans Energy Systems has analyzed several systems of utilizing the geothermal resource at the Great Western barley malting facility. These systems included: direct use of geothermal water; geothermal energy heating process water through an intermediary heat exchanger; coal or gas boosted geothermal systems; and heat pump boosted geothermal system. The analysis examined the steps that are required to process the grain.

Orthogonal Test Analysis on Conditions Affecting Electricity Generation Performance of an Enhanced Geothermal System at Yangbajing Geothermal Field

Directory of Open Access Journals (Sweden)

Yuchao Zeng

2017-12-01

Full Text Available The main conditions affecting electricity generation performance of an enhanced geothermal system (EGS include reservoir porosity, reservoir permeability, rock heat conductivity, water production rate and injection temperature. Presently there is lack of systematic research the relative importance of the five aforementioned conditions. The orthogonal test method is a statistical approach to analyze multi-factor and multi-level influence on system performance. In this work, based on the geological data at Yangbajing geothermal field, we analyzed the five conditions affecting the electricity generation performance of EGS, and ranked the relative importance of the five factors. The results show that the order of the relative importance of the conditions on electric power is water production rate > injection temperature > reservoir porosity > rock heat conductivity > reservoir permeability; the order of the relative importance of the conditions on reservoir impedance is reservoir permeability > injection temperature > water production rate > reservoir porosity > rock heat conductivity; the order of the relative importance of the conditions on pump power is water production rate > reservoir permeability > injection temperature > reservoir porosity > rock heat conductivity, and; the order of the relative importance of the conditions on energy efficiency is water production rate > reservoir permeability > reservoir porosity > injection temperature > rock heat conductivity. The construction of an EGS reservoir should be located at a formation with higher reservoir porosity or rock heat conductivity, while the determination of reservoir permeability, water production rate and injection temperature should be based on the comprehensive target.

Research status of geothermal resources in China

Science.gov (United States)

Zhang, Lincheng; Li, Guang

2017-08-01

As the representative of the new green energy, geothermal resources are characterized by large reserve, wide distribution, cleanness and environmental protection, good stability, high utilization factor and other advantages. According to the characteristics of exploitation and utilization, they can be divided into high-temperature, medium-temperature and low-temperature geothermal resources. The abundant and widely distributed geothermal resources in China have a broad prospect for development. The medium and low temperature geothermal resources are broadly distributed in the continental crustal uplift and subsidence areas inside the plate, represented by the geothermal belt on the southeast coast, while the high temperature geothermal resources concentrate on Southern Tibet-Western Sichuan-Western Yunnan Geothermal Belt and Taiwan Geothermal Belt. Currently, the geothermal resources in China are mainly used for bathing, recuperation, heating and power generation. It is a country that directly makes maximum use of geothermal energy in the world. However, China’s geothermal power generation, including installed generating capacity and power generation capacity, are far behind those of Western European countries and the USA. Studies on exploitation and development of geothermal resources are still weak.

Assessment of the origin and geothermal potential of the thermal waters by hydro-isotope geochemistry: Eskisehir province, Turkey.

Science.gov (United States)

Yuce, Galip; Italiano, Francesco; Yasin, Didem; Taskiran, Lutfi; Gulbay, Ahmet Hilmi

2017-05-01

The thermal fluids vented over Eskisehir province have been investigated for their origin and to estimate the geothermal potential of the area. Thermal waters as well as bubbling and dissolved gases were collected and analysed for their chemical and isotopic features. Their isotopic composition varies in the range from -11.5 to -7.7 ‰ for δ 18 O, -84 and -57 ‰ for δ 2 H, and 0-7.2 TU for tritium. The gases (bubbling and dissolved) are mostly N 2 -dominated with a significant amount of CO 2 . The helium isotopic ratios are in the range of 0.2-0.66 R/Rac, indicate remarkable mantle-He contribution ranging between 2 and 10 % in the whole study area. Considering the estimated geothermal gradient about three times higher than the normal gradient, and the reservoir temperatures estimated to be between 50 and 100 °C using quartz and chalcedony geothermometers, a circulation model was built where possible mixing with shallow waters cool down the uprising geothermal fluids.

Geothermal studies in China

International Nuclear Information System (INIS)

Wang Ji-Yang; Chen Mo-Xiang; Wang Ji-An; Deng Xiao; Wang Jun; Shen Hsien-Chieh; Hsiung Liang-Ping; Yan Shu-Zhen; Fan Zhi-Cheng; Liu Xiu-Wen

1981-01-01

Geothermal studies have been conducted in China continuosly since the end of the 1950's with renewed activity since 1970. Three areas of research are defined: (1) fundamental theoretical research of geothermics, including subsurface temperatures, terrestrial heat flow and geothermal modeling; (2) exploration for geothermal resources and exploitation of geothermal energy; (3) geothermal studies in mines. (orig./ME)

Numerical investigation of the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir: a case study of the Daming geothermal field in China.

Science.gov (United States)

Guo, Xuyang; Song, Hongqing; Killough, John; Du, Li; Sun, Pengguang

2018-02-01

The utilization of geothermal energy is clean and has great potential worldwide, and it is important to utilize geothermal energy in a sustainable manner. Mathematical modeling studies of geothermal reservoirs are important as they evaluate and quantify the complex multi-physical effects in geothermal reservoirs. However, previous modeling efforts lack the study focusing on the emission reduction efficiency and the deformation at geothermal wellbores caused by geothermal water extraction/circulation. Emission efficiency is rather relevant in geothermal projects introduced in areas characterized by elevated air pollution where the utilization of geothermal energy is as an alternative to burning fossil fuels. Deformation at geothermal wellbores is also relevant as significant deformation caused by water extraction can lead to geothermal wellbore instability and can consequently decrease the effectiveness of the heat extraction process in geothermal wells. In this study, the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir in Daming County, China, are numerically investigated based on a coupled multi-physical model. Relationships between the efficiency of emission reduction and heat extraction, deformation at geothermal well locations, and geothermal field parameters including well spacing, heat production rate, re-injection temperature, rock stiffness, and geothermal well placement patterns are analyzed. Results show that, although large heat production rates and low re-injection temperatures can lead to decreased heat production in the last 8 years of heat extraction, they still improve the overall heat production capacity and emission reduction capacity. Also, the emission reduction capacity is positively correlated with the heat production capacity. Deformation at geothermal wellbore locations is alleviated by smaller well spacing, lower heat production rates, and smaller numbers of injectors in the well pattern, and by

Case studies for utilizing groundwater-source and low-enthalpy geothermal resources in Korea

Science.gov (United States)

Kim, K.-H.; Shin, J.; Lee, K.-K.; Lee, T. J.

2012-04-01

As one of the top 10 oil-consuming countries in the world, Korea recently has had a great interest in extending the ways to utilize renewable energy. In this regard, geothermal energy resource is attracting more concerns from both of the government and the research field. Korea has neither active volcanic sites nor areas with abnormally higher heat flow. In spite of these natural conditions, many efforts have been exerted to utilize geothermal energy. Here, we introduce two case studies of using groundwater-source geothermal energy with relatively low-enthalpy: One is a riverbank filtration facility, which has been using some of its riverbank filtrate water for the indoor air-conditioning. The other is the first EGS plant planning site, where a few fault-related artesian wells reaching 70C were discovered lately. Numerical simulations to predict the temperature evolution of the two sites, which is dominated by several hydrogeologic factors, were carried out and compared. Simulation of temperature profile of riverbank filtrate water using HydroGeoSphere shows that the primary factor in determining filtrate water temperature is the pumping rate. It also shows that maintaining the facility operation with present pumping rate for the next 30 years will not cause any significant change of water temperature. However, following the new plan of the facility to install additional 37 wells with 6 times higher pumping rate than the current rate might cause about 2C decrease in filtrate water temperature in 10 years after the extension. Simulation for the temperature evolution in a faulted geothermal reservoir in EGS planning site under the supposed injection-extraction operating conditions were carried out using TOUGH2. A MINC model including a hydraulic discontinuity, which reflected the analysis from several geophysical explorations, was generated. Temperature distribution calculated from the simulation shows a rise of relatively hot geothermal water along the fault plane

Heat flow and geothermal processes in Iceland

Science.gov (United States)

Flóvenz, Ólafur G.; Saemundsson, Kristján

1993-09-01

Heat flow values, derived from temperature measurements in shallow boreholes in Iceland, vary substantially across the country. The near-surface temperature gradients range from almost 0 to 500°C/km. The thermal conductivity of water-saturated rocks varies from 1.6 to 2.0 W/m°C. The temperature gradient in Iceland is mainly dependent on four factors: (1) the regional heat flow through the crust, (2) hydrothermal activity, (3) the permeability of the rock, and (4) residual heat in extinct volcanic centers. As Iceland is mainly made of basaltic material the radiogenic heat production is almost negligible. The thermal conductivity is, on the other hand, mainly influenced by the porosity of the rock; it increases as the porosity decreases. Iceland is made of sequences of flood basalts that formed within the volcanic rift zone—a continuation of the axis of the Mid-Atlantic ridge—and subsequently drifted sideways. Fresh basaltic lava is usually highly porous (30%) and fractured, and heat is mainly transported by convection. Therefore, a very low or even no temperature gradient is observed at shallow levels within the volcanic rift zone. As the basalt becomes buried the pores close due to lithostatic pressure and formation of secondary minerals. Below 500-1000 m depth in an uneroded lava pile, the heat is mainly transported by conduction. In the lowlands and valleys of Iceland outside the volcanic rift zone, 1000-1500 m of the original lava pile has been eroded, leaving thermal conduction as the most important heat transport mechanism. The regional temperature gradient has been measured in drillholes in dense and poorly permeable rocks away from the geothermal fields. The results show that the temperature gradient varies from 50 to 150°C/km. The highest values are found close to the volcanic rift zone and the gradient decreases with distance from the spreading axis. This result is mainly based on numerous shallow boreholes (60-500 m) but in some cases the results

Low-Temperature Projects of the Department of Energy's Geothermal Technologies Program: Evaluation and Lessons Learned

Energy Technology Data Exchange (ETDEWEB)

Williams, Tom; Snyder, Neil; Gosnold, Will

2016-10-23

This paper discusses opportunities and challenges related to the technical and economic feasibility of developing power generation from geothermal resources at temperatures of 150 degrees C and lower. Insights from projects funded by the U.S. Department of Energy (DOE), Geothermal Technologies Office inform these discussions and provide the basis for some lessons learned to help guide decisions by DOE and the industry in further developing this resource. The technical basis for low-temperature geothermal energy is well established and the systems can be economic today in certain situations. However, these applications are far from a 'plug and play' product; successful development today requires a good knowledge of geothermal system design and operation.

[Geothermal system temperature-depth database and model for data analysis]. 5. quarterly technical progress report

Energy Technology Data Exchange (ETDEWEB)

Blackwell, D.D.

1998-04-25

During this first quarter of the second year of the contract activity has involved several different tasks. The author has continued to work on three tasks most intensively during this quarter: the task of implementing the data base for geothermal system temperature-depth, the maintenance of the WWW site with the heat flow and gradient data base, and finally the development of a modeling capability for analysis of the geothermal system exploration data. The author has completed the task of developing a data base template for geothermal system temperature-depth data that can be used in conjunction with the regional data base that he had already developed and is now implementing it. Progress is described.

Ground Source Geothermal District Heating and Cooling System

Energy Technology Data Exchange (ETDEWEB)

Lowe, James William [Ball State Univ., Muncie, IN (United States)

2016-10-21

Ball State University converted its campus from a coal-fired steam boiler district heating system to a ground source heat pump geothermal district system that produces simultaneously hot water for heating and chilled water for cooling. This system will include the installation of 3,600 four hundred feet deep vertical closed loop boreholes making it the largest ground source geothermal district system in the country. The boreholes will act as heat exchangers and transfer heat by virtue of the earth’s ability to maintain an average temperature of 55 degree Fahrenheit. With growing international concern for global warming and the need to reduce worldwide carbon dioxide loading of the atmosphere geothermal is poised to provide the means to help reduce carbon dioxide emissions. The shift from burning coal to utilizing ground source geothermal will increase electrical consumption but an overall decrease in energy use and reduction in carbon dioxide output will be achieved. This achievement is a result of coupling the ground source geothermal boreholes with large heat pump chiller technology. The system provides the thermodynamic means to move large amounts of energy with limited energy input. Ball State University: http://cms.bsu.edu/About/Geothermal.aspx

Geothermal Power Technologies

DEFF Research Database (Denmark)

Montagud, Maria E. Mondejar; Chamorro, C.R.

2017-01-01

Although geothermal energy has been widely deployed for direct use in locations with especial geologic manifestations, its potential for power generation has been traditionally underestimated. Recent technology developments in drilling techniques and power conversion technologies from low......-temperature heat resources are bringing geothermal energy to the spotlight as a renewable baseload energy option for a sustainable energy mix. Although the environmental impact and economic viability of geothermal exploitation must be carefully evaluated for each case, the use of deep low-temperature geothermal...... reservoirs could soon become an important contributor to the energy generation around the world....

Geothermal Thermoelectric Generation (G-TEG) with Integrated Temperature Driven Membrane Distillation and Novel Manganese Oxide for Lithium Extraction

Energy Technology Data Exchange (ETDEWEB)

Renew, Jay [Southern Research Inst., Birmingham, AL (United States); Hansen, Tim [Southern Research Inst., Birmingham, AL (United States)

2017-06-01

Southern Research Institute (Southern) teamed with partners Novus Energy Technologies (Novus), Carus Corporation (Carus), and Applied Membrane Technology, Inc. (AMT) to develop an innovative Geothermal ThermoElectric Generation (G-TEG) system specially designed to both generate electricity and extract high-value lithium (Li) from low-temperature geothermal brines. The process combined five modular technologies including – silica removal, nanofiltration (NF), membrane distillation (MD), Mn-oxide sorbent for Li recovery, and TEG. This project provides a proof of concept for each of these technologies. The first step in the process is silica precipitation through metal addition and pH adjustment to prevent downstream scaling in membrane processes. Next, the geothermal brine is concentrated with the first of a two stage MD system. The first stage MD system is made of a high-temperature material to withstand geothermal brine temperatures up to 150C.° The first stage MD is integrated with a G-TEG module for simultaneous energy generation. The release of energy from the MD permeate drives heat transfer across the TE module, producing electricity. The first stage MD concentrate is then treated utilizing an NF system to remove Ca²⁺ and Mg²⁺. The NF concentrate will be disposed in the well by reinjection. The NF permeate undergoes concentration in a second stage of MD (polymeric material) to further concentrate Li in the NF permeate and enhance the efficiency of the downstream Li recovery process utilizing a Mn-oxide sorbent. Permeate from both the stages of the MD can be beneficially utilized as the permeates will contain less contaminants than the feed water. The concentrated geothermal brines are then contacted with the Mn-oxide sorbent. After Li from the geothermal brine is adsorbed on the sorbent, HCl is then utilized to regenerate the sorbent and recover the Li. The research and development project showed that the Si removal goal (>80%) could

Open heat exchanger for improved heat efficiency in geothermal spas

Energy Technology Data Exchange (ETDEWEB)

Nasrabady, S.J.; Palsson, H.; Saevarsdottir, G.A.

2008-09-15

Hot spas and Jacuzzis are popular in Iceland due to the abundance of reasonably prized geothermal heat available. However the water from the district heating system is too warm to be admitted directly into the spa. For safety reasons the water is mixed with cold water, in order to reduce temperature from about 80 deg C down to 45 deg C, which leads to wasting a large quantity of heat. Therefore a design is suggested here that enables the feeding of geothermal water directly into the spa, omitting the step of mixing it with cold water. The idea is to employ an open heat exchanger that transfers heat from the geothermal water to the bulk water in the spa, before letting it mix with the spa water. A case study was done for one particular spa. Heat load was calculated and measured when the spa was in use, and when it was unused. A design is suggested employing a circular double-plate which is to be placed at the bottom of the spa. This unit will function as an open heat exchanger feeding district heating water into the spa. Free convection takes place at the upper side of the upper plate and forced convection below the upper plate. Heat transfer coefficient for both was calculated. Using results from calculations, temperature distribution at critical parts of spa and plate was modeled. Results are reasonable and promising for a good design that may considerably reduce the energy expenses for a continuously heated geothermal spa

Challenges in Implementing a Multi-Partnership Geothermal Power Plant

Energy Technology Data Exchange (ETDEWEB)

Gosnold, Will; Mann, Michael [Universit of North Dakota; Salehfar, Hossein

2017-03-02

The UND-CLR binary geothermal power plant project is a piggyback operation on a secondary-recovery water-flood project in the Cedar Hills oil field in the Williston Basin. Two open-hole horizontal wells at 2,300 m and 2,400 m depths with lateral lengths of 1,290 m and 860 m produce water at a combined flow of 51 l s -1 from the Lodgepole formation (Miss.) for injection into the Red River formation (Ordovician). The hydrostatic head for the Lodgepole is at ground surface and the pumps, which are set at 650 m depth, have run continuously since 2009. Water temperature at the wellhead is 103 °C and CLR passes the water through two large air-cooled heat exchangers prior to injection. In all aspects, the CLR water flood project is ideal for demonstration of electrical power production from a low-temperature geothermal resource. However, implementation of the project from concept to power production was analogous to breaking trail in deep snow in an old growth forest. There were many hidden bumps, detours, and in some instances immoveable barriers. Problems with investors, cost share, contracts with CLR, resistance from local industry, cost of installation, delays by the ORC supplier, and the North Dakota climate all caused delays and setbacks. Determination and problem solving by the UND team eventually overcame most setbacks, and in April 2016, the site began generating power. Figure 1: Schematic of the water supply well at the UND CLR binary geothermal power plant REFERENCES Williams, Snyder, and Gosnold, 2016, Low Temperature Projects Evaluation and Lesson Learned, GRC Transactions, Vol. 40, 203-210 Gosnold, LeFever, Klenner, Mann, Salehfar, and Johnson, 2010, Geothermal Power from Coproduced Fluids in the Williston Basin, GRC Transactions, Vol. 34, 557-560

Report on the geothermal development promotion survey. No.B-7. Kuwanosawa area; Chinetsu kaihatsu sokushin chosa hokokusho. No. B-7 Kuwanosawa chiiki

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-03-01

The paper summed up the results of the geothermal development promotion survey B 'Kuwanosawa area' which was carried out in Yuzawa city, Akita prefecture, from FY 1998 to FY 1999. In the survey, the following were conducted for the comprehensive analysis: geology/alteration zone survey, gravity exploration, electromagnetic exploration, environmental effect survey, well geology survey by drilling structural boreholes of N11-KN-1 and N12-KN-2, cuttings test, temperature log, temperature recovery test, electrical log, water injection test, etc. The geology in the Kuwanosawa area is composed of Pre-neogene period basement rocks, Neogene system and Quaternary system. In this area, there were recognized no gush of geothermal fluids such as hot spring and fumarolic gas and no obvious geothermal manifestation such as high-temperature places and new geothermal alteration zones. Around N12-KN-2, there exists the geothermal water with comparatively high-temperature/high-Cl concentration which is similar to that in the Wasabizawa area, but how it flows is unknown because there was no lost circulation in the depths of the borehole. Around N11-KN-1, there exists the low-temperature/low-Cl concentration geothermal water originating in meteoric water, and therefore, the area can be a rechargeable area. The Kuwanosawa area is regarded as the periphery of the Wasabizawa-Akinomiya geothermal area. (NEDO)

Report on the geothermal development promotion survey. No.B-7. Kuwanosawa area; Chinetsu kaihatsu sokushin chosa hokokusho. No. B-7 Kuwanosawa chiiki

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-03-01

The paper summed up the results of the geothermal development promotion survey B 'Kuwanosawa area' which was carried out in Yuzawa city, Akita prefecture, from FY 1998 to FY 1999. In the survey, the following were conducted for the comprehensive analysis: geology/alteration zone survey, gravity exploration, electromagnetic exploration, environmental effect survey, well geology survey by drilling structural boreholes of N11-KN-1 and N12-KN-2, cuttings test, temperature log, temperature recovery test, electrical log, water injection test, etc. The geology in the Kuwanosawa area is composed of Pre-neogene period basement rocks, Neogene system and Quaternary system. In this area, there were recognized no gush of geothermal fluids such as hot spring and fumarolic gas and no obvious geothermal manifestation such as high-temperature places and new geothermal alteration zones. Around N12-KN-2, there exists the geothermal water with comparatively high-temperature/high-Cl concentration which is similar to that in the Wasabizawa area, but how it flows is unknown because there was no lost circulation in the depths of the borehole. Around N11-KN-1, there exists the low-temperature/low-Cl concentration geothermal water originating in meteoric water, and therefore, the area can be a rechargeable area. The Kuwanosawa area is regarded as the periphery of the Wasabizawa-Akinomiya geothermal area. (NEDO)

Combination of Well-Logging Temperature and Thermal Remote Sensing for Characterization of Geothermal Resources in Hokkaido, Northern Japan

Directory of Open Access Journals (Sweden)

Bingwei Tian

2015-03-01

Full Text Available Geothermal resources have become an increasingly important source of renewable energy for electrical power generation worldwide. Combined Three Dimension (3D Subsurface Temperature (SST and Land Surface Temperature (LST measurements are essential for accurate assessment of geothermal resources. In this study, subsurface and surface temperature distributions were combined using a dataset comprised of well logs and Thermal Infrared Remote sensing (TIR images from Hokkaido island, northern Japan. Using 28,476 temperature data points from 433 boreholes sites and a method of Kriging with External Drift or trend (KED, SST distribution model from depths of 100 to 1500 m was produced. Regional LST was estimated from 13 scenes of Landsat 8 images. Resultant SST ranged from around 50 °C to 300 °C at a depth of 1500 m. Most of western and part of the eastern Hokkaido are characterized by high temperature gradients, while low temperatures were found in the central region. Higher temperatures in shallower crust imply the western region and part of the eastern region have high geothermal potential. Moreover, several LST zones considered to have high geothermal potential were identified upon clarification of the underground heat distribution according to 3D SST. LST in these zones showed the anomalies, 3 to 9 °C higher than the surrounding areas. These results demonstrate that our combination of TIR and 3D temperature modeling using well logging and geostatistics is an efficient and promising approach to geothermal resource exploration.

Deep Seawater Intrusion Enhanced by Geothermal Through Deep Faults in Xinzhou Geothermal Field in Guangdong, China

Science.gov (United States)

Lu, G.; Ou, H.; Hu, B. X.; Wang, X.

2017-12-01

This study investigates abnormal sea water intrusion from deep depth, riding an inland-ward deep groundwater flow, which is enhanced by deep faults and geothermal processes. The study site Xinzhou geothermal field is 20 km from the coast line. It is in southern China's Guangdong coast, a part of China's long coastal geothermal belt. The geothermal water is salty, having fueled an speculation that it was ancient sea water retained. However, the perpetual "pumping" of the self-flowing outflow of geothermal waters might alter the deep underground flow to favor large-scale or long distant sea water intrusion. We studied geochemical characteristics of the geothermal water and found it as a mixture of the sea water with rain water or pore water, with no indication of dilution involved. And we conducted numerical studies of the buoyancy-driven geothermal flow in the deep ground and find that deep down in thousand meters there is favorable hydraulic gradient favoring inland-ward groundwater flow, allowing seawater intrude inland for an unusually long tens of kilometers in a granitic groundwater flow system. This work formed the first in understanding geo-environment for deep ground water flow.

Evaluation of low-temperature geothermal potential in Cache Valley, Utah. Report of investigation No. 174

Energy Technology Data Exchange (ETDEWEB)

de Vries, J.L.

1982-11-01

Field work consisted of locating 90 wells and springs throughout the study area, collecting water samples for later laboratory analyses, and field measurement of pH, temperature, bicarbonate alkalinity, and electrical conductivity. Na/sup +/, K/sup +/, Ca/sup +2/, Mg/sup +2/, SiO/sub 2/, Fe, SO/sub 4//sup -2/, Cl/sup -/, F/sup -/, and total dissolved solids were determined in the laboratory. Temperature profiles were measured in 12 additional, unused walls. Thermal gradients calculated from the profiles were approximately the same as the average for the Basin and Range province, about 35/sup 0/C/km. One well produced a gradient of 297/sup 0/C/km, most probably as a result of a near-surface occurrence of warm water. Possible warm water reservoir temperatures were calculated using both the silica and the Na-K-Ca geothermometers, with the results averaging about 50 to 100/sup 0/C. If mixing calculations were applied, taking into account the temperatures and silica contents of both warm springs or wells and the cold groundwater, reservoir temperatures up to about 200/sup 0/C were indicated. Considering measured surface water temperatures, calculated reservoir temperatures, thermal gradients, and the local geology, most of the Cache Valley, Utah area is unsuited for geothermal development. However, the areas of North Logan, Benson, and Trenton were found to have anomalously warm groundwater in comparison to the background temperature of 13.0/sup 0/C for the study area. The warm water has potential for isolated energy development but is not warm enough for major commercial development.

What is geothermal steam worth?

International Nuclear Information System (INIS)

Thorhallsson, S.; Ragnarsson, A.

1992-01-01

Geothermal steam is obtained from high-temperature boreholes, either directly from the reservoir or by flashing. The value of geothermal steam is similar to that of steam produced in boilers and lies in its ability to do work in heat engines such as turbines and to supply heat for a wide range of uses. In isolated cases the steam can be used as a source of chemicals, for example the production of carbon dioxide. Once the saturated steam has been separated from the water, it can be transported without further treatment to the end user. There are several constraints on its use set by the temperature of the reservoir and the chemical composition of the reservoir fluid. These constraints are described (temperature of steam, scaling in water phase, gas content of steam, well output) as are the methods that have been adopted to utilize this source of energy successfully. Steam can only be transported over relatively short distances (a few km) and thus has to be used close to the source. Examples are given of the pressure drop and sizing of steam mains for pipelines. The path of the steam from the reservoir to the end user is traced and typical cost figures given for each part of the system. The production cost of geothermal steam is estimated and its sensitivity to site-specific conditions discussed. Optimum energy recovery and efficiency is important as is optimizing costs. The paper will treat the steam supply system as a whole, from the reservoir to the end user, and give examples of how the site-specific conditions and system design have an influence on what geothermal steam is worth from the technical and economic points of view

Advanced Geothermal Turbodrill

Energy Technology Data Exchange (ETDEWEB)

W. C. Maurer

2000-05-01

Approximately 50% of the cost of a new geothermal power plant is in the wells that must be drilled. Compared to the majority of oil and gas wells, geothermal wells are more difficult and costly to drill for several reasons. First, most U.S. geothermal resources consist of hot, hard crystalline rock formations which drill much slower than the relatively soft sedimentary formations associated with most oil and gas production. Second, high downhole temperatures can greatly shorten equipment life or preclude the use of some technologies altogether. Third, producing viable levels of electricity from geothermal fields requires the use of large diameter bores and a high degree of fluid communication, both of which increase drilling and completion costs. Optimizing fluid communication often requires creation of a directional well to intersect the best and largest number of fracture capable of producing hot geothermal fluids. Moineau motor stators made with elastomers cannot operate at geothermal temperatures, so they are limited to the upper portion of the hole. To overcome these limitations, Maurer Engineering Inc. (MEI) has developed a turbodrill that does not use elastomers and therefore can operate at geothermal temperatures. This new turbodrill uses a special gear assembly to reduce the output speed, thus allowing a larger range of bit types, especially tri-cone roller bits, which are the bits of choice for drilling hard crystalline formations. The Advanced Geothermal Turbodrill (AGT) represents a significant improvement for drilling geothermal wells and has the potential to significantly reduce drilling costs while increasing production, thereby making geothermal energy less expensive and better able to compete with fossil fuels. The final field test of the AGT will prepare the tool for successful commercialization.

Development of geothermal resources

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-09-01

This paper describes the geothermal development promotion survey project. NEDO is taking the lead in investigation and development to reduce risks for private business entities and promote their development. The program is being moved forward by dividing the surveys into three ranks of A, B and C from prospects of geothermal resource availability and the state of data accumulation. The survey A lacks number of data, but covers areas as wide as 100 to 300 km{sup 2}, and studies possible existence of high-temperature geothermal energy. The survey B covers areas of 50 to 70 km{sup 2}, investigates availability of geothermal resources, and assesses environmental impacts. The survey C covers areas of 5 to 10 km{sup 2}, and includes production well drilling and long-term discharge tests, other than those carried out by the surveys A and B. Results derived in each fiscal year are evaluated and judged to establish development plans for the subsequent fiscal year. This paper summarizes development results on 38 areas from among 45 areas surveyed since fiscal 1980. Development promotion surveys were carried out over seven areas in fiscal 1994. Development is in progress not only on utilization of high-temperature steam, but also on binary cycle geothermal power generation utilizing hot waters of 80 to 150{degree}C. Fiscal 1994 has carried out discussions for spread and practical use of the systems (particularly on economic effects), and development of small-to-medium scale binary systems. 2 figs., 1 tab.

Light hydrocarbons as redox and temperature indicators in the geothermal field of El Tatio (northern Chile)

Energy Technology Data Exchange (ETDEWEB)

Tassi, F. [University of Florence (Italy). Dept. of Earth Sciences; Martinez, C. [University Catolica del Norte, Antofagasta (Chile). Dept. of Earth Science; Vaselli, O. [University of Florence (Italy). Dept. of Earth Sciences; Institute of Geosciences and Earth Resources, Florence (Italy). National Council of Research; Capaccioni, B. [University of Urbino (Italy). Institute of Volcanology and Geochemistry; Viramonte, J. [National University of Salta (Argentina). Institute GEONORTE and CONICET

2005-11-15

El Tatio (northern Chile), one of the largest geothermal fields of South America, is presently undergoing a new program of geothermal exploration, after the failure of the first exploration phase in the early 1970s. The geochemical features of the fluid discharges characterizing this system mainly consist of boiling pools and fumaroles, and represent the result of a complex mixing process involving 3 main components: (i) hydrothermal; (ii) atmospheric; (iii) magmatic. Chemical reactions involving light hydrocarbons equilibrate at higher temperature than those directly measured in the geothermal wells and calculated on the basis of the composition of the inorganic gas species. This suggests that in the deeper parts of the hydrothermal system temperatures higher than 300{sup o}C may be achieved. Such results can have a strong impact for the evaluation of the potential resources of this geothermal system. Moreover, the chemical characteristics of the organic gas fraction allow the assessment of the chemical-physical conditions governing the geochemical processes acting on geothermal fluids at depth. (author)

Numerical simulations of heat transfer through fractured rock for an enhanced geothermal system development in Seokmodo, Korea

Science.gov (United States)

Shin, Jiyoun; Kim, Kyung-Ho; Hyun, Yunjung; Lee, Kang-Keun

2010-05-01

Estimating the expected capacity and efficiency of energy is a crucial issue in the construction of geothermal plant. It is the lasting temperature of extracted geothermal water that determines the effectiveness of enhanced geothermal systems (EGS), so the heat transfer processes in geothermal reservoirs under site-specific geologic conditions should be understood first. The construction of the first geothermal plant in Korea is under planning in Seokmodo, where a few flowing artesian wells showing relatively high water temperature of around 70°C were discovered lately. The site of interest is a part of the island region, consisting of the reclaimed land surrounded by the sea and small mountains. Geothermal gradient measures approximately 45°C/km and the geothermal water is as saline as seawater. Geologic structure in this region is characterized by the fractured granite. In this study, thermo-hydrological (TH) numerical simulations for the temperature evolution in a fractured geothermal reservoir under the supposed injection-extraction operating conditions were carried out using TOUGH2. Multiple porosity model which is useful to calculate the transient interporosity flow in TH coupled heat transfer problem was used in simulations. Several fracture planes which had been investigated in the field were assigned to have highly permeable properties in order to avoid the averaging approximation and describe the dominant flow through the fractures. This heterogeneous model showed the rise of relatively hot geothermal water in the densely fractured region. The temperature of the extracted geothermal water also increased slowly for 50 years due to the rising flow through the fractures. The most sensitive factor which affects the underground thermal distribution and temperature of geothermal water was permeability of the medium. Change in permeabilities of rock and fracture within the range of 1 order might cause such an extreme change in the temperature of geothermal

Uranium disequilibrium investigation of the Las Cruces East Mesa Geothermal Field

International Nuclear Information System (INIS)

Gross, J.; Cochran, J.; Icerman, L.

1985-03-01

The concentration of dissolved uranium in 33 thermal and nonthermal groundwaters was found to vary from less than 1 part per billion to 285 parts per billion. The uranium-234 to uranium-238 alpha activity ratio of the 33 samples varied from 0.8 to 4.6. Young waters in the recharge area of the Jornada del Muerto Basin are characterized by low uranium concentrations and high activity ratios. Uranium concentrations of groundwaters increase down hydraulic gradient. Concentrations and activity ratios of dissolved uranium in Mesilla Valley groundwater exhibit wide variation and appear to be related to both short-term and long-term removal of groundwater from storage. Geothermal waters exhibit low uranium concentrations and activity ratios. The water produced from New Mexico State University geothermal wells appears to be a mixture of deep upwelling geothermal water and shallow Jornada del Muerto Basin water. The low activity ratio of water from an 800 meter geothermal well may be the result of thermally-induced isotopic equilibration. Isotopic equilibration suggests that higher temperatures may be found deeper within the reservoir

Development of an active solar humidification-dehumidification (HDH) desalination system integrated with geothermal energy

International Nuclear Information System (INIS)

Elminshawy, Nabil A.S.; Siddiqui, Farooq R.; Addas, Mohammad F.

2016-01-01

Highlights: • Productivity increases with increasing geothermal water flow rate up to 0.15 kg/s. • Geothermal energy increases productivity by 187–465% when used with solar energy. • Daytime experimental productivity (8AM-5PM) up to 104 L/m"2 was achieved. • Daily experimental productivity (24 h) up to 192 L/m"2 was achieved. • Fresh potable water can be produced at 0.003 USD/L using this desalination setup. - Abstract: This paper investigates the technical and economic feasibility of using a hybrid solar-geothermal energy source in a humidification-dehumidification (HDH) desalination system. The newly developed HDH system is a modified solar still with air blower and condenser used at its inlet and outlet respectively. A geothermal water tank in a temperature range 60–80 °C which imitates a low-grade geothermal energy source was used to supply heat to water inside the humidification chamber. The experiments were conducted in January 2015 under the climatological conditions of Madinah (latitude: 24°33′N, longitude: 39°36′0″E), Saudi Arabia to study the effect of geothermal water temperature and flow rate on the performance and productivity of proposed desalination system. Analytical model was also developed to compare the effect of solar energy and combined solar-geothermal energy on accumulated productivity. Daytime experimental accumulated productivity up to 104 L/m"2 and daily average gained output ratio (GOR) in the range 1.2–1.58 was achieved using the proposed desalination system. Cost of fresh water produced using the presented desalination system is 0.003 USD/L.

Determination of Ground Heat Exchangers Temperature Field in Geothermal Heat Pumps

Science.gov (United States)

Zhurmilova, I.; Shtym, A.

2017-11-01

For the heating and cooling supply of buildings and constructions geothermal heat pumps using low-potential ground energy are applied by means of ground exchangers. The process of heat transfer in a system of ground exchangers is a phenomenon of complex heat transfer. The paper presents a mathematical modeling of heat exchange processes, the temperature fields are built which are necessary for the determination of the ground array that ensures an adequate supply of low potential energy excluding the freezing of soil around the pipes in the ground heat exchangers and guaranteeing a reliable operation of geothermal heat pumps.

Sustainable renewable energy seawater desalination using combined-cycle solar and geothermal heat sources

KAUST Repository

Missimer, Thomas M.

2013-01-01

Key goals in the improvement of desalination technology are to reduce overall energy consumption, make the process "greener," and reduce the cost of the delivered water. Adsorption desalination (AD) is a promising new technology that has great potential to reduce the need for conventional power, to use solely renewable energy sources, and to reduce the overall cost of water treatment. This technology can desalt seawater or water of even higher salinity using waste heat, solar heat, or geothermal heat. An AD system can operate effectively at temperatures ranging from 55 to 80 °C with perhaps an optimal temperature of 80 °C. The generally low temperature requirement for the feedwater allows the system to operate quite efficiently using an alternative energy source, such as solar power. Solar power, particularly in warm dry regions, can generate a consistent water temperature of about 90 °C. Although this temperature is more than adequate to run the system, solar energy collection only can occur during daylight hours, thereby necessitating the use of heat storage during nighttime or very cloudy days. With increasing capacity, the need for extensive thermal storage may be problematic and could add substantial cost to the development of an AD system. However, in many parts of the world, there are subsurface geothermal energy sources that have not been extensively used. Combining a low to moderate geothermal energy recovery system to an AD system would provide a solution to the thermal storage issue. However, geothermal energy development from particularly Hot Dry Rock is limited by the magnitude of the heat flow required for the process and the thermal conductivity of the rock material forming the heat reservoir. Combining solar and geothermal energy using an alternating 12-h cycle would reduce the probability of depleting the heat source within the geothermal reservoir and provide the most effective use of renewable energy. © 2013 Desalination Publications.

Assessment of stream water chemistry and impact of geothermal fluid in the up-Buyuk Menderes Basin, Turkey.

Science.gov (United States)

Davraz, Aysen; Aksever, Fatma; Afsin, Mustafa

2017-12-01

The discharge of geothermal fluid into the natural water environment may lead to serious damages. In this study, the impact of geothermal waste water on surface water has been investigated in the up-Buyuk Menderes River, Turkey. Thermal return water from district heating and from thermal bath in the Sandıklı region were the most important source of major solutes and trace elements to the up-Buyuk Menderes River and tributaries. The thermal contribution causes a drastic increase in Na, SO 4 ions, EC, and temperature of surface waters. The concentrations of As, Al, B, Fe, Cr, Li, S, P, Pb, U, Mn, and Zn are increasing dramatically downstream of thermal water inputs in the Kufi Creek tributary. In addition to natural thermal water inputs, water quality was impacted by anthropogenic trace and major element inputs from surface waters. The increased of some trace elements (Al, As, B, Cu, Cd, Fe, Mn, P, U) in surface water are related to anthropogenic activities such as agricultural activities, sewage effluents, and stockyards in the study area. Additionally, surface water quality of the up-Buyuk Menderes River and tributaries was evaluated according to standards given by the Environmental Protection Agency of both Turkey and USA. Our study demonstrates the influence of thermal water inputs on water quality of surface waters.

Hydrogeochemical evaluation of conventional and hot dry rock geothermal resource potential in the Clear Lake region, California

Energy Technology Data Exchange (ETDEWEB)

Goff, F.; Adams, A.I.; Trujillo, P.E.; Counce, D.

1993-05-01

Chemistry, stable isotope, and tritium contents of thermal/mineral waters in the Clear Lake region were used to evaluate conventional and hot dry rock (HDR) geothermal potential for electrical generation. Thermal/mineral waters of the Clear Lake region are broadly classified as thermal meteoric and connate types based on chemical and isotopic criteria. Ratios of conservative components such as B/Cl are extremely different among all thermal/mineral waters of the Clear Lake region except for clusters of waters emerging from specific areas such as the Wilbur Springs district and the Agricultural Park area south of Mt. Konocti. In contrast ratios of conservative components in large, homogeneous geothermal reservoirs are constant. Stable isotope values of Clear Lake region waters show a mixing trend between thermal meteoric and connate (generic) end-members. The latter end-member has enriched {delta}D as well as enriched {delta}{sup 18}O, from typical high-temperature geothermal reservoir waters. Tritium data indicate most Clear Lake region waters are mixtures of old and young fluid components. Subsurface equilibration temperature of most thermal/mineral waters of the Clear Lake region is {le}150{degree}C based on chemical geothermometers but it is recognized that Clear Lake region waters are not typical geothermal fluids and that they violate rules of application of many geothermometers. The combined data indicate that no large geothermal reservoir underlies the Clear Lake region and that small localized reservoirs have equilibration temperatures {le}150{degree}C (except for Sulphur Bank mine). HDR technologies are probably the best way to commercially exploit the known high-temperatures existing beneath the Clear Lake region particularly within and near the main Clear Lake volcanic field.

Energetic and exergoeconomic assessment of a multi-generation energy system based on indirect use of geothermal energy

International Nuclear Information System (INIS)

Akrami, Ehsan; Chitsaz, Ata; Nami, Hossein; Mahmoudi, S.M.S.

2017-01-01

In this paper, a geothermal based multi-generation energy system, including organic Rankine cycle, domestic water heater, absorption refrigeration cycle and proton exchange membrane electrolyzer, is developed to generate electricity, heating, cooling and hydrogen. For this purpose, energetic, exergetic and exergoeconomic analysis are undertaken upon proposed system. Also, the effects of some important variables, i.e. geothermal water temperature, turbine inlet temperature and pressure, generator temperature, geothermal water mass flow rate and electrolyzer current density on the several parameters such as energy and exergy efficiencies of the proposed system, heating and cooling load, net electrical output power, hydrogen production, unit cost of each system products and total unit cost of the products are investigated. For specified conditions, the results show that energy and exergy efficiencies of the proposed multi-generation system are calculated about 34.98% and 49.17%, respectively. The highest and lowest total unit cost of the products estimated approximately 23.18 and 22.73 $/GJ, respectively, by considering that geothermal water temperature increases from 185 °C to 215 °C. - Highlights: • A multigeneration energy system based on geothermal energy is developed. • The energetic, exergetic and exergoeconomic analysis are undertaken upon proposed system. • The influences of several significant parameters are investigated. • The energy and exergy efficiencies of the entire system are calculated around 34.98% and 49.17%.

Low-Temperature Projects of the Department of Energy's Geothermal Technologies Program: Evaluation and Lessons Learned: Preprint

Energy Technology Data Exchange (ETDEWEB)

Williams, Tom; Snyder, Neil; Gosnold, Will

2016-12-01

This paper discusses opportunities and challenges related to the technical and economic feasibility of developing power generation from geothermal resources at temperatures of 150 degrees C and lower. Insights from projects funded by the U.S. Department of Energy (DOE), Geothermal Technologies Office inform these discussions and provide the basis for some lessons learned to help guide decisions by DOE and the industry in further developing this resource. The technical basis for low-temperature geothermal energy is well established and the systems can be economic today in certain situations. However, these applications are far from a 'plug and play' product; successful development today requires a good knowledge of geothermal system design and operation.

Exploration for geothermal resources in the Capital District of New York. Final report

Energy Technology Data Exchange (ETDEWEB)

Sneeringer, M.R.; Dunn, J.R.

1981-11-01

Water chemistry, gas analyses, and geophysical methods including gravity and magnetic surveys, microseismic monitoring, and temperature gradient measurements were used in the Capital District area to evaluate the potential for a hydrothermal geothermal system. Water and gas chemistries provided indirect indicators, and temperature gradients provided direct indications of a geothermal system. Gravity results were supportive of gradient and chemistry data, but seismic and magnetic work have thus far provided little information on the potential system. Gradients throughout the area ranged from an average background value of about 10/sup 0/C/km to a high of roughly 44/sup 0/C/km. The highest gradient values, the most unusual water chemistries and largest carbon dioxide exhalations occur along the Saratoga and McGregor faults between Saratoga Springs and Schenectady, and indicate a good potential for a usable hydrothermal geothermal system at depth.

Geochemical study of water-rock interaction processes on geothermal systems of alkaline water in granitic massif; Estudio geoquimico de los procesos de interaccion agua-roca sobre sistemas goetermales de aguas alcalinas en granitoides

Energy Technology Data Exchange (ETDEWEB)

Buil gutierrez, B; Garcia Sanz, S; Lago San Jose, M; Arranz Uague, E; Auque Sanz, L [Universidad de Zaragoza (Spain)

2002-07-01

The study of geothermal systems developed within granitic massifs (with alkaline waters and reducing ORP values) is a topic of increasing scientific interest. These systems are a perfect natural laboratory for studying the water-rock interaction processes as they are defined by three main features: 1) long residence time of water within the system, 2) temperature in the reservoir high enough to favour reaction kinetics and finally, 3) the comparison of the chemistry of the incoming and outgoing waters of the system allows for the evaluation of the processes that have modified the water chemistry and its signature, The four geothermal systems considered in this paper are developed within granitic massifs of the Spanish Central Pyrenes; these systems were studied from a geochemical point of view, defining the major, trace and REE chemistry of both waters and host rocks and then characterizing the composition and geochemical evolution of the different waters. Bicarbonate-chloride-sodic and bicarbonate-sodic compositions are the most representative of the water chemistry in the deep geothermal system, as they are not affected by secondary processes (mixing, conductive cooling, etc). (Author)

A Resource Assessment Of Geothermal Energy Resources For Converting Deep Gas Wells In Carbonate Strata Into Geothermal Extraction Wells: A Permian Basin Evaluation

Energy Technology Data Exchange (ETDEWEB)

Erdlac, Richard J., Jr.

2006-10-12

Previously conducted preliminary investigations within the deep Delaware and Val Verde sub-basins of the Permian Basin complex documented bottom hole temperatures from oil and gas wells that reach the 120-180C temperature range, and occasionally beyond. With large abundances of subsurface brine water, and known porosity and permeability, the deep carbonate strata of the region possess a good potential for future geothermal power development. This work was designed as a 3-year project to investigate a new, undeveloped geographic region for establishing geothermal energy production focused on electric power generation. Identifying optimum geologic and geographic sites for converting depleted deep gas wells and fields within a carbonate environment into geothermal energy extraction wells was part of the project goals. The importance of this work was to affect the three factors limiting the expansion of geothermal development: distribution, field size and accompanying resource availability, and cost. Historically, power production from geothermal energy has been relegated to shallow heat plumes near active volcanic or geyser activity, or in areas where volcanic rocks still retain heat from their formation. Thus geothermal development is spatially variable and site specific. Additionally, existing geothermal fields are only a few 10’s of square km in size, controlled by the extent of the heat plume and the availability of water for heat movement. This plume radiates heat both vertically as well as laterally into the enclosing country rock. Heat withdrawal at too rapid a rate eventually results in a decrease in electrical power generation as the thermal energy is “mined”. The depletion rate of subsurface heat directly controls the lifetime of geothermal energy production. Finally, the cost of developing deep (greater than 4 km) reservoirs of geothermal energy is perceived as being too costly to justify corporate investment. Thus further development opportunities

Klamath Falls geothermal field, Oregon

Energy Technology Data Exchange (ETDEWEB)

Lienau, P.J.; Culver, G.; Lund, J.W.

1989-09-01

Klamath Falls, Oregon, is located in a Known Geothermal Resource Area which has been used by residents, principally to obtain geothermal fluids for space heating, at least since the turn of the century. Over 500 shallow-depth wells ranging from 90 to 2,000 ft (27 to 610 m) in depth are used to heat (35 MWt) over 600 structures. This utilization includes the heating of homes, apartments, schools, commercial buildings, hospital, county jail, YMCA, and swimming pools by individual wells and three district heating systems. Geothermal well temperatures range from 100 to 230{degree}F (38 to 110{degree}C) and the most common practice is to use downhole heat exchangers with city water as the circulating fluid. Larger facilities and district heating systems use lineshaft vertical turbine pumps and plate heat exchangers. Well water chemistry indicates approximately 800 ppM dissolved solids, with sodium sulfate having the highest concentration. Some scaling and corrosion does occur on the downhole heat exchangers (black iron pipe) and on heating systems where the geo-fluid is used directly. 73 refs., 49 figs., 6 tabs.

On geothermal resources of India. Geotectonic aspects and recent developments

Energy Technology Data Exchange (ETDEWEB)

Gupta, M L [National Geophysical Research Inst., Hyderabad (India)

1988-11-10

Research programs launched for exploration and development of the geothermal energy in India, since the 1973-1974 oil embargo, have led to the identification of many potential areas for geothermal resources. Resources comprise high/intermediate/low temperature hydrothermal convection and hot water aquifer systems, geopressured geothermal system and conduction-dominated regimes. Location and properties of these geothermal systems are controlled by the geodynamic and tectonic characteristics of the Indian continental lithosphere Main sectors for the utilization of India's proved and identified geothermal resources are the power generation, space heating, green house cultivation, aquaculture, poultry, sheep breeding, mineral processing, mushroom raising, processing of farm and forest produce, refrigeration, tourism, health-resorts and mineral water bottling. The R and D efforts have given some encouraging results. Geothermal resources of India, although primarily are of medium to low grade, could supplement, to a great extent, direct heat energy needs and may also provide electricity to some of the remote hilly areas. Development of geothermal energy sources in India is likely to get some more attention, with the setting up of separate departments and agencies, by various Provincial Governments, for R and D backing toward the alternate sources of energy.

Data assimilation for the investigation of deep temperature and geothermal energy in the Netherlands.

Science.gov (United States)

Bonté, Damien; Limberger, Jon; Lipsey, Lindsey; Cloetingh, Sierd; van Wees, Jan-Diederik

2016-04-01

Deep geothermal energy systems, mostly for the direct use of heat, have been attracting more and more interest in the past 10 years in Western Europe. In the Netherlands, where the sector took off with the first system in 2005, geothermal energy is seen has a key player for a sustainable future. To support the development of deep geothermal energy system, the scientific community has been working on tools that could be used to highlight area of potential interest for geothermal exploration. In the Netherlands, ThermoGIS is one such tool that has been developed to inform the general public, policy makers, and developers in the energy sector of the possibility of geothermal energy development. One major component incorporated in this tool is the temperature model. For the Netherlands, we created a thermal model at the lithospheric scale that focus on the sedimentary deposits for deep geothermal exploration. This regional thermal modelling concentrates on the variations of geological thermal conductivity and heat production both in the sediments and in the crust. In addition, we carried out special modelling in order to specifically understand convectivity in the basin, focusing on variations at a regional scale. These works, as well as recent improved of geological knowledge in the deeper part of the basin, show interesting evidence for geothermal energy development. At this scale, the aim of this work is to build on these models and, using data assimilation, to discriminate in the actual causes of the observed anomalies. The temperature results obtained for the Netherlands show some thermal patterns that relate to the variation of the thermal conductivity and the geometry of the sediments. There is also strong evidence to indicate that deep convective flows are responsible for thermal anomalies. The combination of conductive and local convective thermal patterns makes the deeper part of the Dutch sedimentary basin of great interest for the development of geothermal

Geothermal progress monitor: Report No. 17

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-01

DOE is particularly concerned with reducing the costs of geothermal power generation, especially with the abundant moderate to low-temperature resources in the US. This concern is reflected in DOE`s support of a number of energy conversion projects. Projects which focus on the costs and performance of binary cycle technology include a commercial demonstration of supersaturated turbine expansions, which earlier studies have indicated could increase the power produced per pound of fluid. Other binary cycle projects include evaluations of the performance of various working fluid mixtures and the development and testing of advanced heat rejection systems which are desperately needed in water-short geothermal areas. DOE is also investigating the applicability of flash steam technology to low-temperature resources, as an economic alternative to binary cycle systems. A low-cost, low-pressure steam turbine, selected for a grant, will be constructed to utilize fluid discharged from a flash steam plant in Nevada. Another project addresses the efficiency of high-temperature flash plants with a demonstration of the performance of the Biphase turbine which may increase the power output of such installations with no increase in fluid flow. Perhaps the most noteworthy feature of this issue of the GPM, the 17th since its inception in 1980, is the high degree of industry participation in federally-sponsored geothermal research and development. This report describes geothermal development activities.

Thermodynamic and economic analysis and optimization of power cycles for a medium temperature geothermal resource

International Nuclear Information System (INIS)

Coskun, Ahmet; Bolatturk, Ali; Kanoglu, Mehmet

2014-01-01

Highlights: • We conduct the thermodynamic and economic analysis of various geothermal power cycles. • The optimization process was performed to minimize the exergy losses. • Kalina cycle is a new technology compared to flash and binary cycles. • It is shown that Kalina cycle presents a viable choice for both thermodynamically and economically. - Abstract: Geothermal power generation technologies are well established and there are numerous power plants operating worldwide. Turkey is rich in geothermal resources while most resources are not exploited for power production. In this study, we consider geothermal resources in Kutahya–Simav region having geothermal water at a temperature suitable for power generation. The study is aimed to yield the method of the most effective use of the geothermal resource and a rational thermodynamic and economic comparison of various cycles for a given resource. The cycles considered include double-flash, binary, combined flash/binary, and Kalina cycle. The selected cycles are optimized for the turbine inlet pressure that would generate maximum power output and energy and exergy efficiencies. The distribution of exergy in plant components and processes are shown using tables. Maximum first law efficiencies vary between 6.9% and 10.6% while the second law efficiencies vary between 38.5% and 59.3% depending on the cycle considered. The maximum power output, the first law, and the second law efficiencies are obtained for Kalina cycle followed by combined cycle and binary cycle. An economic analysis of four cycles considered indicates that the cost of producing a unit amount of electricity is 0.0116 $/kW h for double flash and Kalina cycles, 0.0165 $/kW h for combined cycle and 0.0202 $/kW h for binary cycle. Consequently, the payback period is 5.8 years for double flash and Kalina cycles while it is 8.3 years for combined cycle and 9 years for binary cycle

Rare earth elements in sinters from the geothermal waters (hot springs) on the Tibetan Plateau, China

Science.gov (United States)

Feng, Jin-Liang; Zhao, Zhen-Hong; Chen, Feng; Hu, Hai-Ping

2014-10-01

The mineralogical and geochemical composition of sinters from the geothermal areas on the Tibetan Plateau was determined. They occur as siliceous, salty and calcareous sinters but biogenic siliceous sinters were also found. The analyses indicate that there are no distinct inter -element relationships between individual rare earth elements (REEs) and other elements. Formed from the same geothermal water, the mineralogical and chemical composition of the sinters is influenced by their genesis and formation conditions. The REE distributions depend on the origin of the sinters. Fe-Mn phases in sinters tend to scavenge more REEs from geothermal water. Neither the REE fractionation nor the Ce anomaly seems to be associated with Fe-Mn phases in the sinters. The fourth tetrads of some sinters display weak W-type (concave) effects. In contrast, the third tetrads present large effects in some sinters due to positive Gd anomalies. The origin of the positive Eu anomalies in some sinters seems to be caused by preferential dissolution of feldspars during water-rock interaction. The complexing ligands in geothermal water may contribute significantly to the fractionation of REEs in sinters. The dominant CO32- and HCO3- complexing in geothermal water favors enrichment of heavy REEs in calcareous sinters.

Rodigo Uno (Italy) geothermal thermal energy for crop drying

International Nuclear Information System (INIS)

Facchini, U.; Sordelli, C.; Magnoni, S.; Cantadori, M.

1992-01-01

This paper outlines the chief design and performance features of a forage drying installation which makes use of locally available geothermal energy. The heat exchange is accomplished through a water-air exchanger directly fed by 59 degrees C geothermal springs. Two 80,000 cubic meter/hour ventilators, making use of this energy (58 to 38 degrees C heat exchange), raise the drying air temperature by 16 degrees C, while providing an overall drying capacity of 43,200 kg/day. The balance of available 38 degrees C geothermal energy is being employed by a local aquaculture farm. The paper comments on the economic and environmental benefits being derived from this direct utilization of geothermal energy

Geothermal Today - 1999

Energy Technology Data Exchange (ETDEWEB)

None

2000-05-01

U.S. Department of Energy 1999 Geothermal Energy Program Highlights The Hot Facts Getting into Hot Water Turning Waste water into Clean Energy Producing Even Cleaner Power Drilling Faster and Cheaper Program in Review 1999: The Year in Review JanuaryCal Energy announced sale of Coso geothermal power plants at China Lake, California, to Caithness Energy, for $277 million. U.S. Export-Import Bank completed a $50 million refinancing of the Leyte Geothermal Optimization Project in the Philippines. F

Numerical modeling of the impact of temperature on the behavior of minerals in the Soultz-sous-Forêts enhanced geothermal system

Science.gov (United States)

Van Ngo, Viet; Lucas, Yann; Clément, Alain; Fritz, Bertrand

2015-04-01

diagrams, which are based on the activities of different species such as H4SiO4, Ca2+, Mg2+, and Al3+ and take into account partial CO2 pressure,. The modeling results further suggested that we should pay a special attention to the main minerals (e.g., quartz, calcite and illites) when studying the changes in porosity and permeability of the geothermal reservoir. This study was preparing a simulation of water-rock interaction processes related to these temperature conditions.

High-temperature explosive development for geothermal well stimulation. Final report

Energy Technology Data Exchange (ETDEWEB)

Schmidt, E.W.; Mars, J.E.; Wang, C.

1978-03-31

A two-component, temperature-resistant liquid explosive called HITEX has been developed which is capable of withstanding 561/sup 0/K (550/sup 0/F) for 24 hours in a geothermal environment. The explosive is intended for the stimulation of nonproducing or marginally producing geothermal (hot dry rock, vapor-dominated or hydrothermal) reservoirs by fracturing the strata in the vicinity of a borehole. The explosive is inherently safe because it is mixed below ground downhole from two nondetonable liquid components. Development and safety tests included differential scanning calorimetry, thermal stability, minerals compatibility, drop-weight sensitivity, adiabatic compression, electrostatic discharge sensitivity, friction sensitivity, detonation arrest capability, cook-off tests, detonability at ambient and elevated pressure, detonation velocity and thin film propagation in a wedge.

A renewable energy scenario for Aalborg Municipality based on low-temperature geothermal heat, wind power and biomass

DEFF Research Database (Denmark)

Østergaard, Poul Alberg; Mathiesen, Brian Vad; Möller, Bernd

2010-01-01

Aalborg Municipality, Denmark, wishes to investigate the possibilities of becoming independent of fossil fuels. This article describes a scenario for supplying Aalborg Municipality’s energy needs through a combination of low-temperature geothermal heat, wind power and biomass. Of particular focus...... in the scenario is how low-temperature geothermal heat may be utilised in district heating (DH) systems. The analyses show that it is possible to cover Aalborg Municipality’s energy needs through the use of locally available sources in combination with significant electricity savings, heat savings, reductions...... in industrial fuel use and savings and fuel-substitutions in the transport sector. With biomass resources being finite, the two marginal energy resources in Aalborg are geothermal heat and wind power. If geothermal heat is utilised more, wind power may be limited and vice versa. The system still relies...

Numerical study of coupled heat and mass transfer in geothermal water cooling tower

International Nuclear Information System (INIS)

Bourouni, K.; Bassem, M.M.; Chaibi, M.T.

2008-01-01

Cross flow mechanical cooling towers, widely spreads all over the south region of Tunisia are used for cooling geothermal water for agriculture and domestic ends. These towers are sized empirically and present several problems in regard to operation and electrical energy consumption. This work aims to study the thermal behaviour of this type of cooling towers through a developed mathematical model considering the variation of the water mass flow rate inside the tower. The analysis of the water and air temperatures distribution along the cooling tower had underlined the negative convection phenomenon at a certain height of the tower. This analysis has shown also that the difference in water temperature between the inlet and the outlet of the tower is much higher than the one of air due to the dominance of the evaporative potential compared to the convective one. In addition, the variations of the air humidity along the cooling tower and the quantity of evaporated water have been investigated. The loss of water by evaporation is found to be 5.1% of the total quantity of water feeding the cooling tower. Interesting future prospects are expected for validation of the developed model to optimize the operating of the cooling tower

Humboldt's spa: microbial diversity is controlled by temperature in geothermal environments.

Science.gov (United States)

Sharp, Christine E; Brady, Allyson L; Sharp, Glen H; Grasby, Stephen E; Stott, Matthew B; Dunfield, Peter F

2014-06-01

Over 200 years ago Alexander von Humboldt (1808) observed that plant and animal diversity peaks at tropical latitudes and decreases toward the poles, a trend he attributed to more favorable temperatures in the tropics. Studies to date suggest that this temperature-diversity gradient is weak or nonexistent for Bacteria and Archaea. To test the impacts of temperature as well as pH on bacterial and archaeal diversity, we performed pyrotag sequencing of 16S rRNA genes retrieved from 165 soil, sediment and biomat samples of 36 geothermal areas in Canada and New Zealand, covering a temperature range of 7.5-99 °C and a pH range of 1.8-9.0. This represents the widest ranges of temperature and pH yet examined in a single microbial diversity study. Species richness and diversity indices were strongly correlated to temperature, with R(2) values up to 0.62 for neutral-alkaline springs. The distributions were unimodal, with peak diversity at 24 °C and decreasing diversity at higher and lower temperature extremes. There was also a significant pH effect on diversity; however, in contrast to previous studies of soil microbial diversity, pH explained less of the variability (13-20%) than temperature in the geothermal samples. No correlation was observed between diversity values and latitude from the equator, and we therefore infer a direct temperature effect in our data set. These results demonstrate that temperature exerts a strong control on microbial diversity when considered over most of the temperature range within which life is possible.

Geothermal Risk Reduction via Geothermal/Solar Hybrid Power Plants. Final Report

Energy Technology Data Exchange (ETDEWEB)

Wendt, Daniel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mines, Greg [Idaho National Lab. (INL), Idaho Falls, ID (United States); Turchi, Craig [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhu, Guangdong [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-11-01

There are numerous technical merits associated with a renewable geothermal-solar hybrid plant concept. The performance of air-cooled binary plants is lowest when ambient temperatures are high due to the decrease in air-cooled binary plant performance that occurs when the working fluid condensing temperature, and consequently the turbine exhaust pressure, increases. Electrical power demand is generally at peak levels during periods of elevated ambient temperature and it is therefore especially important to utilities to be able to provide electrical power during these periods. The time periods in which air-cooled binary geothermal power plant performance is lowest generally correspond to periods of high solar insolation. Use of solar heat to increase air-cooled geothermal power plant performance during these periods can improve the correlation between power plant output and utility load curves. While solar energy is a renewable energy source with long term performance that can be accurately characterized, on shorter time scales of hours or days it can be highly intermittent. Concentrating solar power (CSP), aka solar-thermal, plants often incorporate thermal energy storage to ensure continued operation during cloud events or after sunset. Hybridization with a geothermal power plant can eliminate the need for thermal storage due to the constant availability of geothermal heat. In addition to the elimination of the requirement for solar thermal storage, the ability of a geothermal/solar-thermal hybrid plant to share a common power block can reduce capital costs relative to separate, stand-alone geothermal and solar-thermal power plant installations. The common occurrence of long-term geothermal resource productivity decline provides additional motivation to consider the use of hybrid power plants in geothermal power production. Geothermal resource productivity decline is a source of significant risk in geothermal power generation. Many, if not all, geothermal resources

Low-cost low-enthalpy geothermal heat for freshwater production: Innovative applications using thermal desalination processes

KAUST Repository

Bundschuh, Jochen; Ghaffour, NorEddine; Mahmoudi, Hacè ne; Goosen, Mattheus F A; Mushtaq, Shahbaz; Hoinkis, Jan

2015-01-01

The study is dedicated to exploring different types of low-cost low-enthalpy geothermal and their potential integration with conventional thermal-based water desalination and treatment technologies to deliver energy efficient, environmentally friendly solutions for water desalination and treatment, addressing global water crises. Our in-depth investigation through reviews of various low-enthalpy geothermal and conventional thermal-based technologies suggest that the geothermal option is superior to the solar option if low-cost geothermal heat is available because it provides a constant heat source in contrast to solar. Importantly, the stable heat source further allows up-scaling (> 1000 m3/day), which is not currently possible with solar. Solar-geothermal hybrid constellations may also be suitable in areas where both sources are available. The review also discovers that the innovative Membrane distillation (MD) process is very promising as it can be used for many different water compositions, salinity and temperature ranges. Either the geothermal water itself can be desalinated/treated or the geothermal heat can be used to heat feed water from other sources using heat exchangers. However, there are only few economic analyses for large-scale MD units and these are based on theoretical models using often uncertain assumptions resulting in a large variety of results.

Low-cost low-enthalpy geothermal heat for freshwater production: Innovative applications using thermal desalination processes

KAUST Repository

Bundschuh, Jochen

2015-03-01

The study is dedicated to exploring different types of low-cost low-enthalpy geothermal and their potential integration with conventional thermal-based water desalination and treatment technologies to deliver energy efficient, environmentally friendly solutions for water desalination and treatment, addressing global water crises. Our in-depth investigation through reviews of various low-enthalpy geothermal and conventional thermal-based technologies suggest that the geothermal option is superior to the solar option if low-cost geothermal heat is available because it provides a constant heat source in contrast to solar. Importantly, the stable heat source further allows up-scaling (> 1000 m3/day), which is not currently possible with solar. Solar-geothermal hybrid constellations may also be suitable in areas where both sources are available. The review also discovers that the innovative Membrane distillation (MD) process is very promising as it can be used for many different water compositions, salinity and temperature ranges. Either the geothermal water itself can be desalinated/treated or the geothermal heat can be used to heat feed water from other sources using heat exchangers. However, there are only few economic analyses for large-scale MD units and these are based on theoretical models using often uncertain assumptions resulting in a large variety of results.

Geothermometric evaluation of geothermal resources in southeastern Idaho

Science.gov (United States)

Neupane, G.; Mattson, E. D.; McLing, T. L.; Palmer, C. D.; Smith, R. W.; Wood, T. R.; Podgorney, R. K.

2016-01-01

Southeastern Idaho exhibits numerous warm springs, warm water from shallow wells, and hot water from oil and gas test wells that indicate a potential for geothermal development in the area. We have estimated reservoir temperatures from chemical composition of thermal waters in southeastern Idaho using an inverse geochemical modeling technique (Reservoir Temperature Estimator, RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. The temperature estimates in the region varied from moderately warm (59 °C) to over 175 °C. Specifically, hot springs near Preston, Idaho, resulted in the highest reservoir temperature estimates in the region.

Preliminary evaluation of geothermal resource in the Republic of Macedonia

International Nuclear Information System (INIS)

Georgieva, Mirjana; Micevski, Eftim; Gjorgiev, Dushko; Novkovski, Todor; Petrovski, Kiro

1995-01-01

Geothermal resources assessment is the estimation of the thermal energy in the ground, referenced to the mean annual temperature, coupled with an estimation of the amount of energy that might be extracted economically and legally at some reasonable future time. A resource assessment as a statement made at a given time using a given data. It is of only transitory value and must be updated periodically. Macedonia dispose a great amount of geothermal potential, but the geothermal investigation investments are totally reduced, resulting in an un sufficiently using of thermal waters. (Original)

Characterization of Hydrologic and Thermal Properties at Brady Geothermal Field, NV

Science.gov (United States)

Patterson, J.; Cardiff, M. A.; Lim, D.; Coleman, T.; Wang, H. F.; Feigl, K. L.

2017-12-01

Understanding and predicting the temperature evolution of geothermal reservoirs is a primary focus for geothermal power plant operators ensuring continued financial sustainability of the resource. Characterization of reservoir properties - such as thermal diffusivity and hydraulic conductivity - facilitates modeling efforts to develop a better understanding of temperature evolution. As part of the integrated "PoroTomo" experiment, borehole pressure measurements were collected in three monitoring wells of various depths under varying operational conditions at the Brady Geothermal Field near Reno, NV. During normal operational conditions, a vertical profile of borehole temperature to 330 m depth was collected using distributed temperature sensing (DTS) for a period of 5 days. Borehole pressure data indicates 2D flow and shows rapid responses to changes in pumping /injection rates, likely indicating fault-dominated flow. The temperature data show that borehole temperature recovery following cold water slug injection is variable with depth. Late time vertical temperature profiles show the borehole following a shallow geotherm to a depth of approximately 275 meters, below which the temperature declines until a depth of approximately 320 meters, with a stable zone of cold water forming below this, possibly indicating production-related thermal drawdown. A validated heat transfer model is used in conjunction with the temperature data to determine depth-dependent reservoir thermal properties. Hydraulic reservoir properties are determined through inversion of the collected pressure data using MODFLOW. These estimated thermal and hydraulic properties are synthesized with existing structural and stratigraphic datasets at Brady. The work presented herein was funded in part by the Office of Energy Efficiency and Renewable Energy (EERE), U.S. Department of Energy, under Award Number DE-EE0006760.

Isotopic and chemical composition of water and steam discharges from volcanic-magmatic-hydrothermal systems of the Guanacaste Geothermal Province, Costa Rica

Energy Technology Data Exchange (ETDEWEB)

Giggenbach, W.F. (Department of Scientific and Industrial Research, Petone (New Zealand). Chemistry Div.); Soto, R.C. (Instituto Costarricense de Electricidad, San Jose (Costa Rica))

1992-07-01

The Guanacaste Geothermal Province encompasses three major geothermal systems, each centered on its respective volcanic structure: Rincon de la Vieja to the NW, Miravalles in the center and Tenorio to the SE. Each shows corresponding sets of surface manifestations: vapor discharges from fumaroles and steam-heated pools at altitudes >500 m; lower temperature SO{sub 4}-Cl springs on the lower slopes of the respective volcano; and cooler neutral Cl springs to the S of the volcanic chain, at altitudes <500 m. The production of HCO{sub 3}-rich waters is limited to a narrow belt stretching to the S of Miravalles volcano. Chemical and isotopic evidence suggests that the neutral Cl waters, also discharged from deep wells, are derived from a more primitive Cl-SO{sub 4} water formed by transfer of readily mobilised, originally magmatic constituents to deeply circulating groundwater. (author).

Economic study of low temperature geothermal energy in Lassen and Modoc Counties, California

Energy Technology Data Exchange (ETDEWEB)

1977-04-01

The feasibility of using low cost, low temperature geothermal energy in job-producing industries to increase employment and encourage economic development was investigated. The study, encompassing all of Lassen and Modoc Counties, was to be site-specific, referencing candidate geothermal applications to known hot wells and springs as previously determined, or to new wells with specific characteristics as defined in the Scope of Work. The emphasis was to be placed on economically practical and readily achievable applications from known resources. Although both positive and negative findings were found in specific areas of investigation, it is felt that the overall long term prognosis for geothermal energy stimulus to industry in the area is excellent. The applications studied were; greenhouse heating, kiln drying, onion dehydration, feedlots, and aquaculture.

Recovery of energy from geothermal brine and other hot water sources

Science.gov (United States)

Wahl, III, Edward F.; Boucher, Frederic B.

1981-01-01

Process and system for recovery of energy from geothermal brines and other hot water sources, by direct contact heat exchange between the brine or hot water, and an immiscible working fluid, e.g. a hydrocarbon such as isobutane, in a heat exchange column, the brine or hot water therein flowing countercurrent to the flow of the working fluid. The column can be operated at subcritical, critical or above the critical pressure of the working fluid. Preferably, the column is provided with a plurality of sieve plates, and the heat exchange process and column, e.g. with respect to the design of such plates, number of plates employed, spacing between plates, area thereof, column diameter, and the like, are designed to achieve maximum throughput of brine or hot water and reduction in temperature differential at the respective stages or plates between the brine or hot water and the working fluid, and so minimize lost work and maximize efficiency, and minimize scale deposition from hot water containing fluid including salts, such as brine. Maximum throughput approximates minimum cost of electricity which can be produced by conversion of the recovered thermal energy to electrical energy.

Comparative investigation of working fluids for an organic Rankine cycle with geothermal water

Directory of Open Access Journals (Sweden)

Liu Yan-Na

2015-06-01

Full Text Available In this paper, the thermodynamic investigation on the use of geothermal water (130 °C as maximum for power generation through a basic Rankine has been presented together with obtained main results. Six typical organic working fluids (i.e., R245fa, R141b, R290, R600, R152a, and 134a were studied with modifying the input pressure and temperature to the turbine. The results show that there are no significant changes taking place in the efficiency for these working fluids with overheating the inlet fluid to the turbine, i.e., efficiency is a weak function of temperature. However, with the increasing of pressure ratio in the turbine, the efficiency rises more sharply. The technical viability is shown of implementing this type of process for recovering low temperature heat resource.

Geothermal energy

OpenAIRE

Manzella A.

2017-01-01

Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG) emissions. Geothermal energy is the thermal energy stored in the underground, including any contained fluid, which is available for extraction and conversion into energy products. Electricity generation, which nowadays produces 73.7 TWh (12.7 GW of capacity) worldwide, usually requires geothermal resources temperatures of over 100 °C. Fo...

Thermoeconomic Analysis of Hybrid Power Plant Concepts for Geothermal Combined Heat and Power Generation

Directory of Open Access Journals (Sweden)

Florian Heberle

2014-07-01

Full Text Available We present a thermo-economic analysis for a low-temperature Organic Rankine Cycle (ORC in a combined heat and power generation (CHP case. For the hybrid power plant, thermal energy input is provided by a geothermal resource coupled with the exhaust gases of a biogas engine. A comparison to alternative geothermal CHP concepts is performed by considering variable parameters like ORC working fluid, supply temperature of the heating network or geothermal water temperature. Second law efficiency as well as economic parameters show that hybrid power plants are more efficient compared to conventional CHP concepts or separate use of the energy sources.

Development of Genetic Occurrence Models for Geothermal Prospecting

Science.gov (United States)

Walker, J. D.; Sabin, A.; Unruh, J.; Monastero, F. C.; Combs, J.

2007-12-01

, including high heat flow, anomalous temperature water wells, high-temperature indications from aqueous geothermometry and geochemistry, Pliocene or younger ages from low-temperature thermochronometers, as well as more obvious factors such as geysers and fumaroles (which by definition will be missing for blind resources). Our occurrence-model strategy inverts the current approach that relies first on obvious evidence of geothermal activity. We evaluated our approach by retrospectively applying the protocol to the characteristics of producing geothermal fields, and in all cases, known resource areas fit the parameters identified from a genetic perspective.

Biochemical solubilization of toxic salts from residual geothermal brines and waste waters

Science.gov (United States)

Premuzic, Eugene T.; Lin, Mow S.

1994-11-22

A method of solubilizing metal salts such as metal sulfides in a geothermal sludge using mutant Thiobacilli selected for their ability to metabolize metal salts at high temperature is disclosed, The method includes the introduction of mutated Thiobacillus ferrooxidans and Thiobacillus thiooxidans to a geothermal sludge or brine. The microorganisms catalyze the solubilization of metal salts, For instance, in the case of metal sulfides, the microorganisms catalyze the solubilization to form soluble metal sulfates.

Assessment of water management tools for the geothermal reservoir Waiwera (New Zealand)

Science.gov (United States)

Kühn, Michael; Altmannsberger, Charlotte

2016-04-01

Water management tools are essential to ensure the conservation of natural resources. The geothermal hot water reservoir below the village of Waiwera, on the Northern Island of New Zealand is used commercially since 1863. The continuous production of 50 °C hot geothermal water, to supply hotels and spas, has a negative impact on the reservoir. Until the year 1969 from all wells drilled the warm water flow was artesian. Due to overproduction the water needs to be pumped up nowadays. Further, within the years 1975 to 1976 the warm water seeps on the beach of Waiwera ran dry. In order to protect the reservoir and the historical and tourist site in the early 1980s a Water Management Plan was deployed. The "Auckland Regional Water Board" today "Auckland Regional Council" established guidelines to enable a sustainable management [1]. The management plan demands that the water level in the official and appropriate observation well of the council is 0.5 m above sea level throughout the year in average. Almost four decades of data (since 1978 until today) are now available [2]. The minimum water level was observed beginning of the 1980s with -1.25 m and the maximum recently with 1.6 m. The higher the production rates from the field, the lower the water level in the observation well. Highest abstraction rates reached almost 1,500 m3/day and lowest were just above 500 m3/day. Several models of varying complexity where used from purely data driven statistical to fully coupled process simulation models. In all cases the available data were used for calibration and the models were then applied for predictive purposes. We used the Nash-Sutcliffe efficiency index to quantify their predictive ability. The recommendation for the full implementation of the water management plan is the regular revision of an existing multivariate regression model which is based on the Theis well equation. Further, we suggest improving the underlying geological model of the process simulations to

Geothermal development promotion survey. No. B-3 Kumaishi area; Chinethu kaihatsu sokushin chosa seika hokokusho. No. B-3. Kumaishi chiiki

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

This paper summarizes the result of a geothermal resource survey carried out from fiscal 1995 through fiscal 1997 in the Kumaishi Area located in the western center of Oshima Peninsula in the south western part of Hokkaido. The survey for this area was performed with an objective to search the spread of high temperature area continuing from the adjoining Yakumo area where the highest temperature of 233 degrees C has been confirmed in a structural test well (N63-YK-6), to identify high water permeating areas in great depth points underground, and to find possibility of existence of geothermal resources. The survey included geological and alteration zone survey, geochemical survey, gravitation exploration, electromagnetic exploration, drilling and temperature logging of five structural test wells, water injection test, temperature restoration test, core survey and hot water survey. Also performed were environmental effect survey, rock age measurement, alteration age measurement, and fluid inclusion test. As a result of the survey, it was identified that the verified geothermal hot water has been stored in granites with poor water permeability, whose low temperature has not formed convection systems spreading in wide areas despite having been heated, making each system exist in small scale independently. It was estimated that the possibility is low to expect geothermal power generation. (NEDO)

Development of hot water utilizing power plants in fiscal 1999. Development of technology to collect geothermal resources in great depths/Development of technology to excavate geothermal resources in great depths (Designing whole development); 1999 nendo nessui riyo hatsuden plant nado kaihatsu seika hokokusho. Shinbu chinetsu shigen saishu gijutsu no kaihatsu / shinbu chinetsu shigen kussaku gijutsu no kaihatsu (zentai kaihatsu sekkei)

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

Technological development has been made on excavation of geothermal wells, which are dense, hard, and high in temperature and pressure, in developing geothermal resources in great depths. This paper summarizes the achievements in fiscal 1999. This fiscal year has performed the excavation test using an actual well to verify the reliability in practical use of the developed heat-resistant and durable bit. The test was executed by using a bit with a diameter of 8-1/2 inches in a ground bet having a maximum temperature of 300 degrees C in the Yamakawa geothermal field. As a result, good site evaluation was obtained that the wear and tear after lift-up showed no problems, and sufficient performance was verified in the drilling rate and durability. In addition, the low specific gravity cement for high temperature use that has been newly developed was given a cement mixing test to identify its workability at site and hardening properties, at a test well with a temperature of about 40 degrees C in the Okiri geothermal field. The actual well test was performed in a large-scale lost water occurred in a return well during an excavation by Nittestu-Kagoshima Geothermal Company. Effects were recognized in measures to prevent water loss. (NEDO)

Enthalpy restoration in geothermal energy processing system

Science.gov (United States)

Matthews, Hugh B.

1983-01-01

A geothermal deep well energy extraction system is provided of the general type in which solute-bearing hot water is pumped to the earth's surface from a relatively low temperature geothermal source by transferring thermal energy from the hot water to a working fluid for driving a primary turbine-motor and a primary electrical generator at the earth's surface. The superheated expanded exhaust from the primary turbine motor is conducted to a bubble tank where it bubbles through a layer of sub-cooled working fluid that has been condensed. The superheat and latent heat from the expanded exhaust of the turbine transfers thermal energy to the sub-cooled condensate. The desuperheated exhaust is then conducted to the condenser where it is condensed and sub-cooled, whereupon it is conducted back to the bubble tank via a barometric storage tank. The novel condensing process of this invention makes it possible to exploit geothermal sources which might otherwise be non-exploitable.

Selected data for low-temperature (less than 90{sup 0}C) geothermal systems in the United States: reference data for US Geological Survey Circular 892

Energy Technology Data Exchange (ETDEWEB)

Reed, M.J.; Mariner, R.H.; Brook, C.A.; Sorey, M.L.

1983-12-15

Supporting data are presented for the 1982 low-temperature geothermal resource assessment of the United States. Data are presented for 2072 geothermal sites which are representative of 1168 low-temperature geothermal systems identified in 26 States. The low-temperature geothermal systems consist of 978 isolated hydrothermal-convection systems, 148 delineated-area hydrothermal-convection systems, and 42 delineated-area conduction-dominated systems. The basic data and estimates of reservoir conditions are presented for each geothermal system, and energy estimates are given for the accessible resource base, resource, and beneficial heat for each isolated system.

Numerical simulations of heat transfer considering hydraulic discontinuity for an enhanced geothermal system development in Seokmo Island, Korea

Science.gov (United States)

Shin, J.; Kim, K.; Hyun, Y.; Lee, K.; Lee, T.

2011-12-01

The construction of the first geothermal plant in Korea is under planning in Seokmo Island, where a few artesian wells showing relatively high water temperature of around 70 degrees were discovered lately. Geologic structure in this region is characterized by the fractured granite. Numerical simulations for the temperature evolution in a fractured geothermal reservoir in Seokmo Island under the supposed injection-extraction operating conditions were carried out using TOUGH2. A MINC model including a hydraulic discontinuity in Seokmo Island region, which reflected the analysis from several geophysical explorations and drilled rock core, was generated. Supposing the N05°E, NW83° fracture zone containing the pumping range, the numerical simulation results show that temperature of the extracted geothermal water decreases after 15 years of operation, which decreases the overall efficiency of the expected geothermal plant. This is because the colder water from the injection well, which is 400 m apart, begins to flow into the more permeable fracture zone from the 15th year, resulting in a decrease in temperature near the pumping well. Temperature distribution calculated from the simulation also shows a rise of relatively hot geothermal water along the fracture plane. All of the results are different from the non-fracture MINC model, which shows a low temperature contour in concentric circle shape around the injection well and relatively consistent extracting temperature. This demonstrates that the distribution and the structure of fracture system influence the major mass and heat flow mechanisms in geologic medium. Therefore, an intensive geologic investigation for the fractures including their structure, permeability and connecting relation is important. Acknowledgement This study was financially supported by KIGAM, KETEP and BK21.

Geothermal Exploration of the Winston Graben, Central New Mexico, USA

Science.gov (United States)

Sophy, M. J.; Kelley, S. A.

2011-12-01

We are assessing the geothermal potential of the Winston Graben of central New Mexico using borehole temperature logs and geophysical data. The Winston Graben is a late Cenozoic rift basin, part of the larger Rio Grande rift, which is 5 to 10 km wide and 56 km long with northern and southern termini occurring at accommodation zones that coincide with late Cenozoic volcanic lineaments. The graben is interpreted to be symmetric based on geologic mapping, with 2 km of stratigraphic offset on both the western and eastern margins. The graben is bordered by the Black Range to the west and is separated from the Rio Grande valley by the Sierra Cuchillo, a horst block made of Paleozoic rocks intruded by a laccolith. Geothermal and geophysical data, including water table measurements, well temperature logs, thermal conductivity samples, bottom hole temperatures, water chemistry, and gravity data have been extracted from the New Mexico Geothermal Database, part of the National Geothermal Database, and the Geonet Gravity and Magnetic Dataset Repository. Combined with existing geologic maps of the Winston Graben and surroundings, these data help to identify spatial relationships between geologic structures and groundwater parameters and distribution. Geothermal gradients from industry temperature-depth well profiles range from 20°C/km to 60°C/km with a spatial distribution of higher gradients located on the eastern side of the Sierra Cuchillo horst, which is where a mapped warm spring is located. Lower thermal gradients were observed to the west in the groundwater recharge area of the basin. Analysis of Bouguer gravity data indicate a gravity low coinciding with the center of the Winston Graben, which is attributed to be the deepest part of the basin, symetrically surrounded by gravity highs. Gravity highs coincide with the middle Cenozoic Morenci and Chise volcanic lineaments along the northern and southern ends of the graben. The mapped warm spring occurs at the

Geothermal heat potential - the source for heating greenhouses in Southestern Europe

Directory of Open Access Journals (Sweden)

Urbancl Danijela

2016-01-01

Full Text Available The paper presents economically evaluated solutions for heating greenhouses with geothermal potential, if the same greenhouse is placed in two different locations in Southeastern Europe, one in Slovenia and the other in Serbia. The direct geothermal water exploitation using heat exchangers is presented and the remaining heat potential of already used geothermal water is exploited using high temperature heat pumps. Energy demands for heating greenhouses are calculated considering climatic parameters of both locations. Furthermore, different constructions materials are taken into account, and energy demands are evaluated if the same greenhouse is made of 4 mm toughened single glass, double insulated glass or polycarbonate plates. The results show that the geothermal energy usage is economically feasible in both locations, because payback periods are in range from two to almost eight years for different scenarios.

Prokaryotic phylogenetic diversity of Hungarian deep subsurface geothermal well waters.

Science.gov (United States)

Németh, Andrea; Szirányi, Barbara; Krett, Gergely; Janurik, Endre; Kosáros, Tünde; Pekár, Ferenc; Márialigeti, Károly; Borsodi, Andrea K

2014-09-01

Geothermal wells characterized by thermal waters warmer than 30°C can be found in more than 65% of the area of Hungary. The examined thermal wells located nearby Szarvas are used for heating industrial and agricultural facilities because of their relatively high hydrocarbon content. The aim of this study was to reveal the prokaryotic community structure of the water of SZR18, K87 and SZR21 geothermal wells using molecular cloning methods and Denaturing Gradient Gel Electrophoresis (DGGE). Water samples from the outflow pipes were collected in 2012 and 2013. The phylogenetic distribution of archaeal molecular clones was very similar in each sample, the most abundant groups belonged to the genera Methanosaeta, Methanothermobacter and Thermofilum. In contrast, the distribution of bacterial molecular clones was very diverse. Many of them showed the closest sequence similarities to uncultured clone sequences from similar thermal environments. From the water of the SZR18 well, phylotypes closely related to genera Fictibacillus and Alicyclobacillus (Firmicutes) were only revealed, while the bacterial diversity of the K87 well water was much higher. Here, the members of the phyla Thermodesulfobacteria, Proteobacteria, Nitrospira, Chlorobi, OP1 and OPB7 were also detected besides Firmicutes.

Geothermal regimes of the Clearlake region, northern California

Energy Technology Data Exchange (ETDEWEB)

Amador, M. [ed.; Burns, K.L.; Potter, R.M.

1998-06-01

The first commercial production of power from geothermal energy, at The Geysers steamfield in northern California in June 1960, was a triumph for the geothermal exploration industry. Before and since, there has been a search for further sources of commercial geothermal power in The Geysers--Clear Lake geothermal area surrounding The Geysers. As with all exploration programs, these were driven by models. The models in this case were of geothermal regimes, that is, the geometric distribution of temperature and permeability at depth, and estimates of the physical conditions in subsurface fluids. Studies in microseismicity and heat flow, did yield geophysical information relevant to active geothermal systems. Studies in stable-element geochemistry found hiatuses or divides at the Stoney Creek Fault and at the Collayomi Fault. In the region between the two faults, early speculation as to the presence of steamfields was disproved from the geochemical data, and the potential existence of hot-water systems was predicted. Studies in isotope geochemistry found the region was characterized by an isotope mixing trend. The combined geochemical data have negative implications for the existence of extensive hydrothermal systems and imply that fluids of deep origin are confined to small, localized systems adjacent to faults that act as conduits. There are also shallow hot-water aquifers. Outside fault-localized systems and hot-water aquifers, the area is an expanse of impermeable rock. The extraction of energy from the impermeable rock will require the development and application of new methods of reservoir creation and heat extraction such as hot dry rock technology.

Mixing effects on geothermometric calculations of the Newdale geothermal area in the Eastern Snake River Plain, Idaho

Energy Technology Data Exchange (ETDEWEB)

Ghanashayam Neupane; Earl D. Mattson; Travis L. McLing; Cody J. Cannon; Thomas R. Wood; Trevor A. Atkinson; Patrick F. Dobson; Mark E. Conrad

2016-02-01

The Newdale geothermal area in Madison and Fremont Counties in Idaho is a known geothermal resource area whose thermal anomaly is expressed by high thermal gradients and numerous wells producing warm water (up to 51 °C). Geologically, the Newdale geothermal area is located within the Eastern Snake River Plain (ESRP) that has a time-transgressive history of sustained volcanic activities associated with the passage of Yellowstone Hotspot from the southwestern part of Idaho to its current position underneath Yellowstone National Park in Wyoming. Locally, the Newdale geothermal area is located within an area that was subjected to several overlapping and nested caldera complexes. The Tertiary caldera forming volcanic activities and associated rocks have been buried underneath Quaternary flood basalts and felsic volcanic rocks. Two southeast dipping young faults (Teton dam fault and an unnamed fault) in the area provide the structural control for this localized thermal anomaly zone. Geochemically, water samples from numerous wells in the area can be divided into two broad groups – Na-HCO3 and Ca-(Mg)-HCO3 type waters and are considered to be the product of water-rhyolite and water-basalt interactions, respectively. Each type of water can further be subdivided into two groups depending on their degree of mixing with other water types or interaction with other rocks. For example, some bivariate plots indicate that some Ca-(Mg)-HCO3 water samples have interacted only with basalts whereas some samples of this water type also show limited interaction with rhyolite or mixing with Na-HCO3 type water. Traditional geothermometers [e.g., silica variants, Na-K-Ca (Mg-corrected)] indicate lower temperatures for this area; however, a traditional silica-enthalpy mixing model results in higher reservoir temperatures. We applied a new multicomponent equilibrium geothermometry tool (e.g., Reservoir Temperature Estimator, RTEst) that is based on inverse geochemical modeling which

El Centro Geothermal Utility Core Field Experiment environmental-impact report and environmental assessment

Energy Technology Data Exchange (ETDEWEB)

1979-08-01

The City of El Centro is proposing the development of a geothermal energy utility core field experiment to demonstrate the engineering and economic feasibility of utilizing moderate temperature geothermal heat, on a pilot scale, for space cooling, space heating, and domestic hot water. The proposed facility is located on part of a 2.48 acre (1 hectare) parcel owned in fee by the City in the southeastern sector of El Centro in Imperial County, California. Geothermal fluid at an anticipated temperature of about 250/sup 0/F (121/sup 0/C) will heat a secondary fluid (water) which will be utilized directly or processed through an absorption chiller, to provide space conditioning and water heating for the El Centro Community Center, a public recreational facility located approximately one-half mile north of the proposed well site. The geothermal production well will be drilled to 8500 feet (2590m) and an injection well to 4000 feet (1220m) at the industrially designated City property. Once all relevant permits are obtained it is estimated that site preparation, facility construction, the completion and testing of both wells would be finished in approximately 26 weeks. The environmental impacts are described.

Estimate of Hot Dry Rock Geothermal Resource in Daqing Oilfield, Northeast China

Directory of Open Access Journals (Sweden)

Guangzheng Jiang

2016-10-01

Full Text Available Development and utilization of deep geothermal resources, especially a hot dry rock (HDR geothermal resource, is beneficial for both economic and environmental consideration in oilfields. This study used data from multiple sources to assess the geothermal energy resource in the Daqing Oilfield. The temperature logs in boreholes (both shallow water wells and deep boreholes and the drilling stem test temperature were used to create isothermal maps in depths. Upon the temperature field and thermophysical parameters of strata, the heat content was calculated by 1 km × 1 km × 0.1 km cells. The result shows that in the southeastern part of Daqing Oilfield, the temperature can reach 150 °C at a depth of 3 km. The heat content within 3–5 km is 24.28 × 1021 J, wherein 68.2% exceeded 150 °C. If the recovery factor was given by 2% and the lower limit of temperature was set to be 150 °C, the most conservative estimate for recoverable HDR geothermal resource was 0.33 × 1021 J. The uncertainties of the estimation are mainly contributed to by the temperature extrapolation and the physical parameter selections.

Exploration for geothermal resources in the Capital District of New York. Volume 1. Final report

Energy Technology Data Exchange (ETDEWEB)

1981-11-01

Water chemistry, gas analyses, and geophysical methods including gravity and magnetic surveys, microseismic monitoring, and temperature gradient measurements were used in the Capital District area to evaluate the potential for a hydrothermal geothermal system. Water and gas chemistries provided indirect indicators, and temperature gradients provided direct indications of a geothermal system. Gravity results were supportive of gradient and chemistry data, but seismic and magnetic work have thus far provided little information on the potential system. Gradients throughout the area ranged from an average background value of about 10/sup 0/C/km to a high of roughly 44/sup 0/C/km. The highest gradient values, the most unusual water chemistries and largest carbon dioxide exhalations occur along the Saratoga and McGregor faults between Saratoga Springs and Schenectady, and indicate a good potential for a usable hydrothermal geothermal system at depth.

Geothermal Monitoring of Kueishantao Island Offshore of Northeastern Taiwan

Directory of Open Access Journals (Sweden)

Hsieh Tang Chiang

2010-01-01

Full Text Available To understand the geothermal variation of the active volcano, Kueishantao island, we conducted continuous monitoring of borehole temperatures beginning in July 2006. Fifteen miniature temperature loggers with resolution better than 0.001 degree were deployed at different depths in a 290-m well. The borehole temperatures ranged between 22 and 34 degree . No significant annual variation was found below 30 m depth. We divided the geotherm into three sections. The shallow one, at a depth less than 110 m, showed an extreme negative geothermal gradient of -0.6 degree (100 m-1, which may be strongly affected by the convection of shallow water. The middle section, at a depth between 110 and 250 m, had a geotherm of 9.7 degree (100 m-1. The heat flow was estimated to be 153 mW m-2, on the same order as that acquired on the seafloor around Kueishantao island. The lower portion, below 250 m depth, showed a geotherm of -8.5 degree (100 m-1 which may be effected by a fracture zone identified by the drilling data. The average geotherm for the whole hole is 4.8 degree (100 m-1. Several thermal events with amplitudes of -0.023 ~ 0.015 degree and durations of tens of hours were found in different depths in the well. These events have been identified to correlate with the occurrences of typhoons. During the study period there were 17 earthquakes greater than 3.4 in magnitude and within 50 km radius of Kueishantao. However, we did not find any significant relationships between earthquake occurcence and temperature variations in the borehole. More observation data are needed to discuss the mechanism of temperature variation.

Geothermal spas

International Nuclear Information System (INIS)

Woodruff, J.L.; Takahashi, P.K.

1990-01-01

The spa business, part of the health and fitness industry that has sprung up in recent years, is highly successful world-wide. The most traditional type of spa is the geothermal spa, found in geothermal areas around the world. In Japan, for example, some 2,000 geothermal spas and resorts generate $6 billion annually. Hawaii has an ideal environment for geothermal spas, and several locations in the islands could supply warm mineral water for spa development. Hawaii receives about 6 million visitors annually, a high percentage of whom are familiar with the relaxing and therapeutic value of geothermal spas, virtually guaranteeing the success of this industry in Hawaii. Presently, Hawaii does not have a single geothermal spa. This paper reports that the geothermal spa business is an industry whose time has come, an industry that offers very promising investment opportunities, and one that would improve the economy while expanding the diversity of pleasurable vacation options in Hawaii

A novel design approach for small scale low enthalpy binary geothermal power plants

International Nuclear Information System (INIS)

Gabbrielli, Roberto

2012-01-01

Highlights: ► Off-design analysis of ORC geothermal power plants through the years and the days. ► Thermal degradation of the geothermal source reduces largely the plant performances. ► The plant capacity factor is low if the brine temperature is far from the design value. ► The performances through the life are more important than those at the design point. ► ORC geothermal power plants should be designed with the end-life brine temperature. - Abstract: In this paper a novel design approach for small scale low enthalpy binary geothermal power plants is proposed. After the suction, the hot water (brine) superheats an organic fluid (R134a) in a Rankine cycle and, then, is injected back underground. This fact causes the well-known thermal degradation of the geothermal resource during the years. Hence, the binary geothermal power plants have to operate with conditions that largely vary during their life and, consequently, the most part of their functioning is executed in off-design conditions. So, as the novel approach here proposed, the design temperature of the geothermal resource is selected between its highest and lowest values, that correspond to the beginning and the end of the operative life of the geothermal power plant, respectively. Hence, using a detailed off-design performance model, the optimal design point of the geothermal power plant is evaluated maximizing the total actualized cash flow from the incentives for renewable power generation. Under different renewable energy incentive scenarios, the power plant that is designed using the lowest temperature of the geothermal resource always results the best option.

Geothermic Characters Of The Most Promising Geothermal Filed For Power Generation In Republic Of Yemen

Directory of Open Access Journals (Sweden)

Al Kubati M.

2017-07-01

Full Text Available This paper presents geothermal exploration and their geothermometric characteristics in the western part of Yemen. Geologically this volcanic province totals areas approximately 45000 km2. Tectonically the study area is considered one of the most active in the Arabian Plate boundaries that affected by the opening of the Red Sea and the Gulf of Aden as well as by the African rift valley. Extensive field work had been carried out to evaluate the geothermal characteristics of this area. Water and gas samples were collected from hundreds of thermal springs and shallow domestic wells and geochemically analyzed and reported. Temperatures and PH values range from 35 to 96.3 C and from 4.5 to 8.5 respectively. Deep geothermal gradient indicates that the geothermal gradients in the western part of the province Red Sea coast are relatively high up to 182 C at the depth of 3290 m. Volcanic units are affected by hydrothermal processes and became intensively altered. By applying geothermometric methods four geothermal fields have been primarily identified they are Al-Lisi and Isbil Dhamar province Al-Qafr Ibb province Damt Dhala province and the Red Sea coast geothermal fields and three water types were recognized which are Na-HCO3-Cl-S and Ca-Na-Cl and Na HCO3.Results from Al-Lisi and Isbil geothermal area are considered the most promising field. Geothermal detail studies have been achieves and location of the first geothermal exploration well is located in Al-Lisi and Isbil field.By applyig geophisical methods Iso- Resistivity contour mapsthese maps reflected high resistivity areas and low.Clearly shows the low resistivity values incentral and Western part of the study area about 11amp937mWhile up Resistivity values to the area in the eastern 600amp937m.Also through the use ofthe different current electrode spacing AB2 700 1000 1500 and 2000m.We find the low- Resistivity areas becoming more widespread and concentrated in the center of the study area and

Heat transfer problems for the production of hydrogen from geothermal energy

International Nuclear Information System (INIS)

Sigurvinsson, J.; Mansilla, C.; Arnason, B.; Bontemps, A.; Marechal, A.; Sigfusson, T.I.; Werkoff, F.

2006-01-01

Electrolysis at low temperature is currently used to produce Hydrogen. From a thermodynamic point of view, it is possible to improve the performance of electrolysis while functioning at high temperature (high temperature electrolysis: HTE). That makes it possible to reduce energy consumption but requires a part of the energy necessary for the dissociation of water to be in the form of thermal energy. A collaboration between France and Iceland aims at studying and then validating the possibilities of producing hydrogen with HTE coupled with a geothermal source. The influence of the exit temperature on the cost of energy consumption of the drilling well is detailed. To vaporize the water to the electrolyser, it should be possible to use the same technology currently used in the Icelandic geothermal context for producing electricity by using a steam turbine cycle. For heating the steam up to the temperature needed at the entrance of the electrolyser three kinds of heat exchangers could be used, according to specific temperature intervals

THE MAXIMUM EFFECT OF DEEP LAKES ON TEMPERATURE PROFILES – DETERMINATION OF THE GEOTHERMAL GRADIENT

Directory of Open Access Journals (Sweden)

Eppelbaum L. V.

2009-07-01

Full Text Available Understanding the climate change processes on the basis of geothermal observations in boreholes is an important and at the same time high-intricate problem. Many non-climatic effects could cause changes in ground surface temperatures. In this study we investigate the effects of deep lakes on the borehole temperature profilesobserved within or in the vicinity of the lakes. We propose a method based on utilization of Laplace equation with nonuniform boundary conditions. The proposed method makes possible to estimate the maximum effect of deep lakes (here the term "deep lake" means that long term mean annual temperature of bottom sediments can beconsidered as a constant value on the borehole temperature profiles. This method also allows one to estimate an accuracy of the determination of the geothermal gradient.

Environmental impact in geothermal fields

International Nuclear Information System (INIS)

Birkle, P.; Torres R, V.; Gonzalez P, E.; Guevara G, M.

1996-01-01

Generally, water exploitation and deep steam of geothermal fields may be cause of a pollution potential on the surface, specially by the chemical composition of geothermal water which has a high concentration of minerals, salts and heavy metals. The utilization of stable isotopes as deuterium and oxygen 18 as radioactive tracers and water origin indicators allow to know the trajectories and sources of background waters as well as possible moistures between geothermal waters and meteoric waters. Some ions such as chlorides and fluorides present solubilities that allow their register as yet long distances of their source. (Author)

Feasibility of Geothermal Energy Extraction from Non-Activated Petroleum Wells in Arun Field

Science.gov (United States)

Syarifudin, M.; Octavius, F.; Maurice, K.

2016-09-01

The big obstacle to develop geothermal is frequently came from the economical viewpoint which mostly contributed by the drilling cost. However, it potentially be tackled by converting the existing decommissioned petroleum well to be converted for geothermal purposes. In Arun Field, Aceh, there are 188 wells and 62% of them are inactive (2013). The major obstacle is that the outlet water temperature from this conversion setup will not as high as the temperature that come out from the conventional geothermal well, since it will only range from 60 to 180oC depending on several key parameters such as the values of ground temperature, geothermal gradient in current location, the flow inside of the tubes, and type of the tubes (the effect from these parameters are studied). It will just be considered as low to medium temperature, according to geothermal well classification. Several adjustments has to be made such as putting out pipes inside the well that have been used to lift the oil/gas and replacing them with a curly long coil tubing which act as a heat exchanger. It will convert the cold water from the surface to be indirectly heated by the hot rock at the bottom of the well in a closed loop system. In order to make power production, the binary cycle system is used so that the low to medium temperature fluid is able to generate electricity. Based on this study, producing geothermal energy for direct use and electricity generation in Arun Field is technically possible. In this study case, we conclude that 2900 kW of electricity could be generated. While for-direct utility, a lot of local industries in Northern Sumatera could get the benefits from this innovation.

Geothermal resources in the Republic of Macedonia

International Nuclear Information System (INIS)

Micevski, Eftim; Georgieva, Mirjana; Petrovski, Kiro; Lonchar, Ilija

1995-01-01

The Republic of Macedonia is situated in the central part of the Balcan Peninsula and covers a surface of 25. 713 km 2 Its territory is found in one of the most significant geothermal zones in this part of Balkans. The earths crust in this region suffers poli phase structural deformations, which as a result gives different structural features. The geothermal explorations in the Republic of Macedonia intensively started to conduct after 1970, after the first effects of the energy crisis. As a result of these explorations, more than 50 springs of mineral and thermo mineral waters with a total yield of more than 1.400 I./sec. And proved exploitation reservoirs of more than 1.000 I./sec. with temperatures higher than the medium year seasons hesitations for this part of the Earth in the boundaries of 20-75 o C with significant quantities of geothermal energy. This paper will shortly present the available geothermal resources and classification, according the type of geothermal energy, hydro geothermal, lithogeothermal and according the way of transport of the geothermal energy, convective and conductive systems. The next will present short descriptions of the resources, the degree of exploitation and the prognosis dimensions of the reservoirs. (Original)

Hydro-geochemical and isotopic fluid evolution of the Los Azufres geothermal field, Central Mexico

International Nuclear Information System (INIS)

Gonzalez-Partida, E.; Carrillo-Chavez, A.; Levresse, G.; Tello-Hinojosa, E.; Venegas-Salgado, S.; Ramirez-Silva, G.; Pal-Verma, M.; Tritlla, J.; Camprubi, A.

2005-01-01

Hydrothermal alteration at Los Azufres geothermal field is mostly propylitic with a progressive dehydration with depth and temperature increase. Argillic and advanced argillic zones overlie the propylitic zone owing to the activity of gases in the system. The deepest fluid inclusions (proto-fluid) are liquid-rich with low salinity, with NaCl dominant fluid type and ice melting temperatures (T mi ) near zero (0 deg C), and salinities of 0.8 wt% NaCl equivalent. The homogenization temperature (T h ) = 325 ± 5 deg C. The boiling zone shows T h = ±300 deg C and apparent salinities between 1 and 4.9 wt% NaCl equivalent, implying a vaporization process and a very important participation of non-condensable gases (NCGs), mostly CO 2 . Positive clathrate melting temperatures (fusion) with T h = 150 deg C are observed in the upper part of the geothermal reservoir (from 0 to 700 m depth). These could well be the evidence of a high gas concentration. The current water produced at the geothermal wells is NaCl rich (geothermal brine) and is fully equilibrated with the host rock at temperatures between T = 300 and 340 deg C. The hot spring waters are acid-sulfate, indicating that they are derived from meteoric water heated by geothermal steam. The NCGs related to the steam dominant zone are composed mostly of CO 2 (80-98% of all the gases). The gases represent between 2 and 9 wt% of the total mass of the fluid of the reservoir. The authors interpret the evolution of this system as deep liquid water boiling when ascending through fractures connected to the surface. Boiling is caused by a drop of pressure, which favors an increase in the steam phase within the brine ascending towards the surface. During this ascent, the fluid becomes steam-dominant in the shallowest zone, and mixes with meteoric water in perched aquifers. Stable isotope compositions (δ 18 O-δD) of the geothermal brine indicate mixing between meteoric water and a minor magmatic component. The enrichment in δ 18

Fiscal 1992 report on geothermal development promotion survey (Development of geothermal reservoir assessment technique); 1989 nendo chinetsu kaihatsu sokushin chosa (Chinetsu choryusou hyoka shuho kaihatsu hokokusho)

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-03-01

Efforts were exerted in fiscal 1984-1992 to develop techniques for appropriately assessing a geothermal reservoir for its productivity for duly predicting the optimum scale of power generation to be provided thereby. In the development of simulators, geothermal reservoir simulators (SING-1, -2, -3) and a geothermal well 2-phase flow simulator (WENG) were developed. As for the treatment of fractures in a reservoir and of substances soluble in the hot water, the methods for dealing with them were improved and augmented. In a model field study in a Hokkaido forest, reservoir pressure continuous observation and monitoring, temperature logging and pressure logging for existing wells, and geothermal fluid chemical analysis were performed for reservoir analysis, in which both natural state simulation and history mapping excellently reproduced the temperature and pressure distributions. The temperature and pressure distributions in a natural state simulation, out of the results of an analysis of the Oguni district model field, Kumamoto Prefecture, agreed not only with those in the natural state but also with the pressure transition data in the observation well. (NEDO)

Application of telluric-telluric profiling combined with magnetotelluric and self-potential methods to geothermal exploration in the Fujian Province, China

Science.gov (United States)

Pham, Van-Ngoc; Boyer, Danièle; Yuan, Xue Cheng; Liu, Shao Cheng

1995-05-01

In the Fujian Province, southeastern China, most of the hot springs emerge in fluviatile valleys and the geothermal resources are mainly medium and low temperature ones by mixing of hot water with cold superficial groundwater. The occurrence of the thermal waters is controlled by deep tectonic fractures in the bedrock where higher-temperature geothermal reservoirs of economic interest are present. The objective of this study is to detect the deeper active hydrothermal zone under a thick sedimentary cover by geoelectrical methods. In the Gui-An site, the combination of telluric-telluric profiling and magnetotelluric methods turns out very efficient to delineate more accurately the width of the deep conductive fracture zone. Moreover, the self-potential method allows us to localize the most active geothermal zone by electrofiltration processes above a convective cell of hot water which flows up from a deep source. The combined results constitute a possible guide for deep geothermal exploration currently encountered in several geothermal regions over the world.

Report on geothermal development promotion survey in fiscal 1999. Survey on hot water (collection and analysis of hot water) in Tsujinodake Area No. B-6; 1999 nendo chinetsu kaihatsu sokushin chosa hokokusho. Nessui no chosa (nessui no saishu oyobi bunseki) No.B-6 Tsujinodake chiiki

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-10-01

This paper reports the survey on hot water in the geothermal development promotion survey in fiscal 1999 in the Tsujinodake area. The hot water pumped up at the N11-TD-2 well is considered to have been originated from sea water mixed with the same amount of meteoric water including waters from Ikeda Lake and Unagi Pond, and been heated mainly by heat conduction. The hot water temperature near the well is 120 to 130 degrees C, but the upper stream of hot water flow is estimated to be 160 to 230 degrees C. The test samples collected and analyzed are those pumped up from depths greater than 1,500 m, having the same origin as the high temperature hot water of higher than 200 degrees C flowing sideways at the relatively shallow portions (depths of 400 to 800 m). The hot water is estimated to be rising from deep portions of mainly the north-east shore of Unagi Pond in which exhalation bands are located, and its temperature is considered to be 260 to 270 degrees C at deep sections. The high temperature geothermal reservoir spreading in relatively shallow sections of the N11-TD-2 well mainly around the vicinity of the north-east shore of Unagi Pond has a high possibility of being continued even to the vicinity of the west Ibusuki area in the north-east direction. However, the spread of the geothermal reservoir with high temperatures (200 degrees C or higher) is considered not too large in the direction of the Matsugakubo in the north-west and the Narikawa area direction in the south-east. (NEDO)

Community structure and function of high-temperature chlorophototrophic microbial mats inhabiting diverse geothermal environments

DEFF Research Database (Denmark)

Klatt, Christian G.; Inskeep, William P.; Herrgard, Markus

2013-01-01

Six phototrophic microbial mat communities from different geothermal springs (YNP) were studied using metagenome sequencing and geochemical analyses. The primary goals of this work were to determine differences in community composition of high-temperature phototrophic mats distributed across...... the Yellowstone geothermal ecosystem, and to identify metabolic attributes of predominant organisms present in these communities that may correlate with environmental attributes important in niche differentiation. Random shotgun metagenome sequences from six phototrophic communities (average 53Mbp/site) were...

17th Symposium of NEDO projects. Geothermal subcommittee; Chinetsu bunkakai. Dai 17 kai jigyo hokokukai

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-09-01

Described herein are the reports presented to the geothermal subcommittee. The NEDO's Geothermal Research Department is developing the technologies for accurately predicting the reservoir changes in the future by the geothermal development promotion investigations for distributed conditions of geothermal resources and related environmental impacts, and also by clarifying the hydrogic characteristics of the fracture systems which form the reservoirs. The department is also implementing the projects for investigating/ researching possibilities of resources distribution conditions and utilization for eventual commercialization of the deep underground geothermal resources, and also investigating utilization of small- to medium-sized geothermal binary power generation systems for effective utilization of unutilized geothermal energy. The geothermal technology development group is developing the technologies for the binary cycle power generation plants which effectively utilize unutilized medium- to high-temperature geothermal water for power generation, and also the technologies for collecting conditions at the bottom of a geothermal well being excavated in real time to improve efficiency and precision of the excavation. The other technologies being developed include those for excavation and production essential for development of power generation systems using high-temperature rocks and deep underground geothermal resources, the former being expected to contribute to expanded utilization of geothermal resources and the latter to increased geothermal power generation capacity. (NEDO)

17th Symposium of NEDO projects. Geothermal subcommittee; Chinetsu bunkakai. Dai 17 kai jigyo hokokukai

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-09-01

Described herein are the reports presented to the geothermal subcommittee. The NEDO's Geothermal Research Department is developing the technologies for accurately predicting the reservoir changes in the future by the geothermal development promotion investigations for distributed conditions of geothermal resources and related environmental impacts, and also by clarifying the hydrogic characteristics of the fracture systems which form the reservoirs. The department is also implementing the projects for investigating/ researching possibilities of resources distribution conditions and utilization for eventual commercialization of the deep underground geothermal resources, and also investigating utilization of small- to medium-sized geothermal binary power generation systems for effective utilization of unutilized geothermal energy. The geothermal technology development group is developing the technologies for the binary cycle power generation plants which effectively utilize unutilized medium- to high-temperature geothermal water for power generation, and also the technologies for collecting conditions at the bottom of a geothermal well being excavated in real time to improve efficiency and precision of the excavation. The other technologies being developed include those for excavation and production essential for development of power generation systems using high-temperature rocks and deep underground geothermal resources, the former being expected to contribute to expanded utilization of geothermal resources and the latter to increased geothermal power generation capacity. (NEDO)

Geothermal investigations in West Virginia

Energy Technology Data Exchange (ETDEWEB)

Hendry, R.; Hilfiker, K.; Hodge, D.; Morgan, P.; Swanberg, C.; Shannon, S.S. Jr.

1982-11-01

Deep sedimentary basins and warm-spring systems in West Virginia are potential geothermal resources. A temperature gradient map based on 800 bottom-hole temperatures for West Virginia shows that variations of temperature gradient trend northeasterly, parallel to regional structure. Highest temperature gradient values of about 28/sup 0/C/km occur in east-central West Virginia, and the lowest gradients (18/sup 0/C/km) are found over the Rome Trough. Results from ground-water geochemistry indicate that the warm waters circulate in very shallow aquifers and are subject to seasonal temperature fluctuations. Silica heat-flow data in West Virginia vary from about 0.89 to 1.4 HFU and generally increase towards the west. Bouguer, magnetic, and temperature gradient profiles suggest that an ancient rift transects the state and is the site of several deep sedimentary basins.

Geothermal applications on the Madison (Pahasapa) aquifer system in South Dakota. Final report, October 1, 1976--September 30, 1977

Energy Technology Data Exchange (ETDEWEB)

Gries, J.P.

1977-09-01

Pertinent geologic, hydrologic, and chemical data for the Madison Formation underlying western South Dakota are presented in text and in graphic form. A temperature anomaly in west central South Dakota makes 130 to 160/sup 0/F water available at depths of less than 3500 ft. A central geothermal space heating system designed for Midland, South Dakota indicates that by 1980 geothermal heat will be competitive with existing energy sources. Preliminary tests indicate the superiority of 304 or 316 stainless steel for fabrication of equipment to utilize the warm, corrosive Madison water. South Dakota has no statutes governing geothermal resources; under existing water law, geothermal water would be classified as a top priority domestic use. Suggestions are made for state legislation pertaining to the development of geothermal energy.

FY 1998 report on the verification survey of geothermal exploration technology, etc. 2/2. Survey of deep geothermal resource; 1998 nendo chinetsu tansa gijutsu nado kensho chosa hokokusho. 2/2. Shinbu chinetsu shigen chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-12-01

For the purpose of commercializing deep geothermal resource, a deep exploration well of 4000m class was drilled in the existing geothermal development area to survey the situation of deep geothermal resource existence and the availability. Concretely, the deep geothermal exploration well was drilled for study in the Kakkonda area, Shizukuishi town, Iwate prefecture, to clarify the situation of deep geothermal resource existence and the whole image of geothermal system. Consideration was made of the deep geothermal exploration method, systematization of deep high temperature drilling technology, and availability of deep geothermal resource. The results of the survey were summed up as follows: 1) general remarks; 2) deep exploration well drilling work; 3) details of the study. This report contained 3). In 3), the items were as follows: heightening of accuracy of the deep geothermal resource exploration method, making of a geothermal model in the Kakkonda area, study of deep drilling technology, study of deep fluid utilization technology, and making of a guide for deep geothermal resource exploration/development in the Kakkonda area. As to the technology of high temperature deep geothermal well drilling, studies were made of the borehole cooling method, mud water cooling method, survey of deterioration of casing with age, etc. (NEDO)

District space heating potential of low temperature hydrothermal geothermal resources in the southwestern United States. Technical report

Energy Technology Data Exchange (ETDEWEB)

McDevitt, P.K.; Rao, C.R.

1978-10-01

A computer simulation model (GIRORA-Nonelectric) is developed to study the economics of district space heating using geothermal energy. GIRORA-Nonelectric is a discounted cashflow investment model which evaluates the financial return on investment for space heating. This model consists of two major submodels: the exploration for and development of a geothermal anomaly by a geothermal producer, and the purchase of geothermal fluid by a district heating unit. The primary output of the model is a calculated rate of return on investment earned by the geothermal producer. The results of the sensitivity analysis of the model subject to changes in physical and economic parameters are given in this report. Using the results of the economic analysis and technological screening criteria, all the low temperature geothermal sites in Southwestern United States are examined for economic viability for space heating application. The methodology adopted and the results are given.

Geothermal regime of Tarim basin, NW China: insights from borehole temperature logging

Science.gov (United States)

Liu, S.; Lei, X.

2013-12-01

Geothermal regime of sedimentary basin is vital for understanding basin (de)formation process, hydrocarbon generation status and assessing the resource potential. Located at the Precambrian craton block, the Tarim basin is the largest intermountain basin in China, which is also the ongoing target of oil and gas exploration. Previous knowledge of thermal regime of this basin is from limited oil exploration borehole testing temperature, the inherent deficiency of data of this type makes accurate understanding of its thermal regime impossible. Here we reported our latest steady temperature logging results in this basin and analyze its thermal regime as well. In this study, 10 temperature loggings are conducted in the northern Tarim basin where the major oil and gas fields are discovered. All the boreholes for temperature logging are non-production wells and are shut in at least more than 2~3 years, ensuring the temperature equilibrium after drilling. The derived geothermal gradient varies from 20.2 to 26.1 degree/km, with a mean of 22.0 degree/km. However, some previous reported gradients in this area are obviously lower than our results; for example, the previous gradient of THN2 well is 13.2 degree/km but 23.2 degree/km in this study, and not enough equilibrium time in previous logging accounts for this discrepancy. More important, it is found that high gradients usually occur in the gas field and the gradients of the gas fields are larger than those in other oil fields, indicating higher thermal regime in gas field. The cause of this phenomenon is unclear, and the upward migration of hot fluid along fault conduit is speculated as the possible mechanism for this high geothermal anomaly in the oil and gas fields. Combined with measured thermal conductivity data, 10 new heat flow values are also achieved, and the heat flow of the Tarim basin is between 38mW/m2 and 52mW/m2, with a mean of 43 mW/m2. This relatively low heat flow is coincident with that of typical

Uranium-thorium series radionuclides in brines and reservoir rocks from two deep geothermal boreholes in the Salton Sea geothermal field, southeastern California

International Nuclear Information System (INIS)

Zukin, J.G.; Hammond, D.E.; Ku, Tehlung; Elders, W.A.

1987-01-01

Naturally occurring U and Th series radionuclides have been analyzed in high temperature brines (∼ 300 degree C, 25 wt% dissolved solids) and associated rocks from two deep geothermal wells located on the northeastern margin of the Salton Sea Geothermal Field (SSGF). These data are part of a study of the SSGF as a natural analog of possible radionuclide behavior near a nuclear waste repository constructed in salt beds, and permit evaluation of some characteristics of water-rock interaction in the SSGF

Direct application of geothermal energy in the Republic of Macedonia

International Nuclear Information System (INIS)

Dimitrov, Konstantin

1995-01-01

The use of geothermal energy for balneology purposes has a history of many centuries. There is also a more than 30 years tradition for heating greenhouses. So called energy crisis of 70-ties and 80-ties provoked geology investigations in order to find possible energy sources, and development of systems for application of low-temperature geothermal water. Tere are a list of projects with direct application of geothermal energy for heating greenhouses, drying agricultural products. heating of public buildings and industrial projects, swimming pools , sanitary warm water preparation, industrial uses, etc. The essential energetic characteristics of different projects are presented in the paper. For the main projects a technical description of characteristics of the heating systems is given, and good technical solutions are underlined. Also the mistakes presented in some projects are listed. (Original)

Hydrogeochemistry and reservoir model of Fuzhou geothermal field, China

Science.gov (United States)

Huang, H. F.; Goff, Fraser

1986-03-01

Fuzhou geothermal field is a low- to intermediate-temperature geothermal system consisting of meteoric water that circulates deeply along faults. The area of the field is about 9 km 2 but it is elongated in a NNW-trending direction. Fluids in the field are controlled by a series of four NNW extensional faults in Cretaceous granitic basement (Fuzhou fault zone). These faults feed warm waters into overlying permeable Quaternary sediments. The hydrothermal system consists of north and south parts whose chemical compositions are subtly different. In the northern part the system discharges sulfate/chloride waters with relatively low chloride concentrations, but in the south the system discharges chloride waters having relatively high chloride concentrations. Maximum wellhead temperatures are 97°C, which agrees with the chalcedony geothermometer in many cases. Based on the solubility of quartz, the deep-reservoir temperature cannot exceed 123 to 131°C. From heat and mass balance calculations, we conclude that the present total extracted capacity of fluid from the reservoir (20,000 tons/day) could be doubled without noticeable drawdown. We estimate the recoverable heat in the reservoir to be about 1.71 × 10 11 MJ.

Geothermal Potential Analysis Using Landsat 8 and Sentinel 2 (Case Study: Mount Ijen)

Science.gov (United States)

Sukojo, B. M.; Mardiana, R.

2017-12-01

Geothermal energy is also a heat energy contained in the earth’s internal. Indonesia has a total geothermal potential of around 27 GWe. The government is eager for the development of geothermal in Indonesia can run well so that geothermal can act as one of the pillars of national energy. However, the geothermal potential has not been fully utilized. One of the geothermal potention is Mount Ijen. Mount Ijen is a strato volcano that has a crater lake with a depth of about 190 m and has a very high degree of acidity and the volume of lake water is very large. With the abundance of potential geothermal potential in Indonesia, it is necessary to have an activity in the form of integrated geoscience studies to be able to maximize the potential content that exists in a geothermal area. One of the studies conducted is to do potential mapping. This research performs image data processing of Landsat 8, Sentinel 2, RBI Map, and preliminary survey data. This research carried out the Vegetation Index, surface temperature and altitude. The equipment used in this research includes image processing software, number processing software, GPS Handheld and Laptop. Surface Temperatures in the Mount Ijen have anomalies with large temperatures ranging between 18° C to 38° C. The best correlation value of altitude and ground surface temperature is -0.89 ie the correlation of January surface temperature. While the correlation value of Landsat 8 and Sentinel 2 vegetation index was 0.81. The land cover confidence matrix scored 80%. Land cover in the research area is dominated by forests by 35% of the research area. There is a potential area of geothermal potential is very high on Mount Ijen with an area of 39.43 hectares located in Wongsorejo District and adjacent to District Sempol.

Geothermal Small Business Workbook [Geothermal Outreach and Project Financing

Energy Technology Data Exchange (ETDEWEB)

Elizabeth Battocletti

2003-05-01

Small businesses are the cornerstone of the American economy. Over 22 million small businesses account for approximately 99% of employers, employ about half of the private sector workforce, and are responsible for about two-thirds of net new jobs. Many small businesses fared better than the Fortune 500 in 2001. Non-farm proprietors income rose 2.4% in 2001 while corporate profits declined 7.2%. Yet not all is rosy for small businesses, particularly new ones. One-third close within two years of opening. From 1989 to 1992, almost half closed within four years; only 39.5% were still open after six years. Why do some new businesses thrive and some fail? What helps a new business succeed? Industry knowledge, business and financial planning, and good management. Small geothermal businesses are no different. Low- and medium-temperature geothermal resources exist throughout the western United States, the majority not yet tapped. A recent survey of ten western states identified more than 9,000 thermal wells and springs, over 900 low- to moderate-temperature geothermal resource areas, and hundreds of direct-use sites. Many opportunities exist for geothermal entrepreneurs to develop many of these sites into thriving small businesses. The ''Geothermal Small Business Workbook'' (''Workbook'') was written to give geothermal entrepreneurs, small businesses, and developers the tools they need to understand geothermal applications--both direct use and small-scale power generation--and to write a business and financing plan. The Workbook will: Provide background, market, and regulatory data for direct use and small-scale (< 1 megawatt) power generation geothermal projects; Refer you to several sources of useful information including owners of existing geothermal businesses, trade associations, and other organizations; Break down the complicated and sometimes tedious process of writing a business plan into five easy steps; Lead you

Better temperature predictions in geothermal modelling by improved quality of input parameters

DEFF Research Database (Denmark)

Fuchs, Sven; Bording, Thue Sylvester; Balling, N.

2015-01-01

Thermal modelling is used to examine the subsurface temperature field and geothermal conditions at various scales (e.g. sedimentary basins, deep crust) and in the framework of different problem settings (e.g. scientific or industrial use). In such models, knowledge of rock thermal properties...

Geothermal system boundary at the northern edge of Patuha Geothermal Field based on integrated study of volcanostratigraphy, geological field mapping, and cool springs contamination by thermal fluids

Science.gov (United States)

Suryantini; Rachmawati, C.; Abdurrahman, M.

2017-12-01

Patuha Geothermal System is a volcanic hydrothermal system. In this type of system, the boundary of the system is often determined by low resistivity (10 ohm.m) anomaly from Magnetotelluric (MT) or DC-Resistivity survey. On the contrary, during geothermal exploration, the system boundary often need to be determined as early as possible even prior of resistivity data available. Thus, a method that use early stage survey data must be developed properly to reduce the uncertainty of the geothermal area extent delineation at the time the geophysical data unavailable. Geological field mapping, volcanostratigraphy analysis and fluid chemistry of thermal water and cold water are the data available at the early stage of exploration. This study integrates this data to delineate the geothermal system boundary. The geological mapping and volcanostratigraphy are constructed to limit the extent of thermal and cold springs. It results that springs in the study area are controlled hydrologically by topography of Patuha Volcanic Crown (complex) or so called PVC, the current geothermal field and Masigit Volcanic Crown (complex) or so called MVC, the dormant volcano not associated with active geothermal system. Some of the cold springs at PVC are contaminated by subsurface steam heated outflow while others are not contaminated. The contaminated cold springs have several characteristics such as higher water temperature than ambient temperature at the time it was measured, higher total disolved solid (TDS), and lower pH. The soluble elements analysis support the early contamination indication by showing higher cation and anion, and positive oxygen shifting of stable isotope of these cool springs. Where as the uncontaminated spring shows similar characteristic with cool springs occur at MVC. The boundary of the system is delineated by an arbitrary line drawn between distal thermal springs from the upflow or contaminated cool springs with the cool uncontaminated springs. This boundary is

Boron isotopes in geothermal systems

International Nuclear Information System (INIS)

Aggarwal, J.

1997-01-01

Boron is a highly mobile element and during water-rock reactions, boron is leached out of rocks with no apparent fractionation. In geothermal systems where the water recharging the systems are meteoric in origin, the B isotope ratio of the geothermal fluid reflects the B isotope ratio of the rocks. Seawater has a distinctive B isotope ratio and where seawater recharges the geothermal system, the B isotope ratio of the geothermal system reflects the mixing of rock derived B and seawater derived B. Any deviations of the actual B isotope ratio of a mixture reflects subtle differences in the water-rock ratios in the cold downwelling limb of the hydrothermal system. This paper will present data from a variety of different geothermal systems, including New Zealand; Iceland; Yellowston, USA; Ibusuki, Japan to show the range in B isotope ratios in active geothermal systems. Some of these systems show well defined mixing trends between seawater and the host rocks, whilst others show the boron isotope ratios of the host rock only. In geothermal systems containing high amounts of CO 2 boron isotope ratios from a volatile B source can also be inferred. (auth)

Geothermal. Possibilities of use of the geothermal energy in the Colombian Atlantic Coast and general aspects on this energy type

International Nuclear Information System (INIS)

Lozano, E.

1987-01-01

With base in the compilation and prosecution of the geologic information and available geophysics in the Departments of Cordoba, Sucre, Bolivar, Atlantic and Magdalena and of the analysis of the results obtained for samples of thermal waters, the possible existence of attractive reas; geothermically was evaluated by the light of the main constituent elements of a geothermal field: Source of heat. Reservoir. Waterproof covering. Recharge area. The absence of recent volcanic manifestations as much in surface as to shallow depths, the nonexistence of a source of heat of economic interest is suggested. The presence of thermal manifestations in 3 towns of the Atlantic Costa shows results of the chemical analyses characterized by the drop silica concentration (92 ppm) and high concentration of bicarbonates (504 ppm) that which identifies to waters of low temperature, what reinforces the nonexistence of a source of significant heat. With the current information it is but attractiveness to focus the investigations in the Atlantic Costa toward the use in other such energy ways as the lot, eolic, biomass, Ph; that toward the use of endogenous fluids. It is included information related with the exploration and exploitation of a geothermal field and with the economic evaluation for geothermal plants of several capacities. Additionally specific examples of four countries in the world that you/they generate electricity with base in geothermal vapor

Development of thermal fractures in two Dutch geothermal doublets

NARCIS (Netherlands)

Loeve, D.; Veldkamp, J.G.; Peters, E.; Wees, J.D.A.M. van

2015-01-01

In the production well of a low-enthalpy geothermal doublet hot water is pumped from reservoirs at about 50-1007deg;C. After passing through a heat exchanger, the cold water is re-injected at about 20-357deg;C in the injection well into the reservoir, which initially has the same temperature as the

Hybrid Cooling for Geothermal Power Plants: Final ARRA Project Report

Energy Technology Data Exchange (ETDEWEB)

Bharathan, D.

2013-06-01

Many binary-cycle geothermal plants use air as the heat rejection medium. Usually this is accomplished by using an air-cooled condenser (ACC) system to condense the vapor of the working fluid in the cycle. Many air-cooled plants suffer a loss of production capacity of up to 50% during times of high ambient temperatures. Use of limited amounts of water to supplement the performance of ACCs is investigated. Deluge cooling is found to be one of the least-cost options. Limiting the use of water in such an application to less than one thousand operating hours per year can boost plant output during critical high-demand periods while minimizing water use in binary-cycle geothermal power plants.

Use of geothermal heat for crop drying and related agricultural applications. Final report

Energy Technology Data Exchange (ETDEWEB)

Gordon, T.J.; Wright, T.C.; Fein, E.; Munson, T.R.; Richmond, R.C.

1978-03-01

Observations led to the selection of the alfalfa dehydration industry for in-depth analysis of the application of moderate-temperature geothermal heat. Six geothermal heat exchanger/dryer configurations were examined. A low-temperature conveyor dryer using geothermal water to supply all required heat was chosen for site-specific analysis, the retrofitting of a large alfalfa dehydration plant within the Heber KGRA in the Imperial Valley, California. Even in the most favorable scenario--sharing a geothermal pipeline with the neighboring fertilizer plant--geothermal retrofitting would increase the price of the alfalfa ''dehy'' about 40 percent. The geothermal brine is estimated to cost $2.58/million Btu's compared with a 1977 natural gas cost of $1.15. Capital cost for heat exchangers and the new dryers is estimated at $3.3 million. The Heber plant appeared to offer the only good opportunity for geothermal retrofitting of an existing alfalfa dehydration plant. Construction of new plants at geothermal resource sites cannot be justified due to the uncertain state of the ''dehy'' industry. Use of geothermal heat for drying other crops may be much more promising. The potato dehydration industry, which is concentrated in the geothermal-rich Snake River Valley of Idaho, appears to offer good potential for geothermal retrofitting; about 4.7 x 10{sup 12}Btu's are used annually by plants within 50 miles of resources. Drying together at the geothermal wellhead several crops that have interlocking processing seasons and drying-temperature requirements may be quite attractive. The best ''multicrop drying center'' site identified was at Power Ranch Wells, Arizona; 34 other sites were defined. Agricultural processing applications other than drying were investigated briefly.

Health impacts of geothermal energy

International Nuclear Information System (INIS)

Layton, D.W.; Anspaugh, L.R.

1982-01-01

Geothermal resources are used to produce electrical energy and to supply heat for non-electric applications like residential heating and crop drying. The utilization of geothermal energy consists of the extraction of hot water or steam from an underground reservoir followed by different methods of surface processing along with the disposal of liquid, gaseous, and even solid wastes. The focus of this paper is on electric power production using geothermal resources greater than 150 0 C because this form of geothermal energy utilization has the most serious health-related consequences. Based on measurements and experience at existing geothermal power plants, atmospheric emissions of non-condensing gases such as hydrogen sulphide and benzene pose the greatest hazards to public health. Surface and ground waters contaminated by discharges of spent geothermal fluids constitute another health hazard. In this paper it is shown that hydrogen sulphide emissions from most geothermal power plants are apt to cause odour annoyances among members of the exposed public -some of whom can detect this gas at concentrations as low as 0.002 ppmv. A risk-assessment model is used to estimate the lifetime risk of incurring leukaemia from atmospheric benzene caused by 2000 MW(e) of geothermal development in California's Imperial Valley. Also assessed is the risk of skin cancer due to the ingestion of river water in New Zealand that is contaminated by waste geothermal fluids containing arsenic. Finally, data on the occurrence of occupational disease in the geothermal industry is briefly summarized. (author)

Spatial Characteristics of Geothermal Spring Temperatures and Discharge Rates in the Tatun Volcanic Area, Taiwan

Science.gov (United States)

Jang, C. S.; Liu, C. W.

2014-12-01

The Tatun volcanic area is the only potential volcanic geothermal region in the Taiwan island, and abundant in hot spring resources owing to stream water mixing with fumarolic gases. According to the Meinzer's classification, spring temperatures and discharge rates are the most important properties for characterizing spring classifications. This study attempted to spatially characterize spring temperatures and discharge rates in the Tatun volcanic area, Taiwanusing indicator kriging (IK). First, data on spring temperatures and discharge rates, which were collected from surveyed data of the Taipei City Government, were divided into high, moderate and low categories according to spring classification criteria, and the various categories were regarded as estimation thresholds. Then, IK was adopted to model occurrence probabilities of specified temperatures and discharge rates in springs, and to determine their classifications based on estimated probabilities. Finally, nine combinations were obtained from the classifications of temperatures and discharge rates in springs. Moreover, the combinations and features of spring water were spatially quantified according to seven sub-zones of spring utilization. A suitable and sustainable development strategy of the spring area was proposed in each sub-zone based on probability-based combinations and features of spring water.The research results reveal that the probability-based classifications using IK provide an excellent insight in exploring the uncertainty of spatial features in springs, and can provide Taiwanese government administrators with detailed information on sustainable spring utilization and conservation in the overexploited spring tourism areas. The sub-zones BT (Beitou), RXY (Rd. Xingyi), ZSL (Zhongshanlou) and LSK (Lengshuikeng) with high or moderate discharge rates are suitable to supply spring water for tourism hotels.Local natural hot springs should be planned in the sub-zones DBT (Dingbeitou), ZSL, XYK

Geothermal resources of the northern gulf of Mexico basin

Science.gov (United States)

Jones, P.H.

1970-01-01

Published geothermal gradient maps for the northern Gulf of Mexico basin indicate little or no potential for the development of geothermal resources. Results of deep drilling, from 4000 to 7000 meters or more, during the past decade however, define very sharp increases in geothermal gradient which are associated with the occurrence of abnormally high interstitial fluid pressure (geopressure). Bounded by regional growth faults along the landward margin of the Gulf Basin, the geopressured zone extends some 1300 km from the Rio Grande (at the boundary between the United States and Mexico) to the mouth of the Mississippi river. Gulfward, it extends to an unknown distance across the Continental Shelf. Within geopressured deposits, geothermal gradients range upwards to 100 ??C/km, being greatest within and immediately below the depth interval in which the maximum pressure gradient change occurs. The 120 ??C isogeotherm ranges from about 2500 to 5000 m below sea level, and conforms in a general way with depth of occurrence of the top of the geopressured zone. Measured geostatic ratios range upward to 0.97; the maximum observed temperature is 273 ??C, at a depth of 5859 m. Dehydration of montmorillonite, which comprises 60 to 80 percent of clay deposited in the northern Gulf Basin during the Neogene, occurs at depths where temperature exceeds about 80 ??C, and is generally complete at depths where temperature exceeds 120 ??C. This process converts intracrystalline and bound water to free pore water, the volume produced being roughly equivalent to half the volume of montmorillonite so altered. Produced water is fresh, and has low viscosity and density. Sand-bed aquifers of deltaic, longshore, or marine origin form excellent avenues for drainage of geopressured deposits by wells, each of which may yield 10,000 m3 or more of superheated water per day from reservoirs having pressures up to 1000 bars at depths greater than 5000 m. ?? 1971.

Geothermal fields of China

Science.gov (United States)

Kearey, P.; HongBing, Wei

1993-08-01

There are over 2500 known occurrences of geothermal phenomena in China. These lie mainly in four major geothermal zones: Xizang (Tibet)-Yunnan, Taiwan, East Coast and North-South. Hot water has also been found in boreholes in major Mesozoic-Cenozoic sedimentary basins. This paper presents a summary of present knowledge of these geothermal zones. The geological settings of geothermal occurrences are associated mainly with magmatic activity, fault uplift and depressional basins and these are described by examples of each type. Increased multipurpose utilisation of geothermal resources is planned and examples are given of current usages.