Title: Geophysical survey for deep geothermal energy exploitation at the site Nova Paka Author: Magda Karousová Supervisor: Prof. RNDr. Miloš Karous, DrSc. Supervisor's e-mail address: karous@geonika.com The topic of this thesis is a literature search of geological, geophysical, and geothermal information about wider surroundings of the area of Nova Paka and a complete geophysical survey focused on mapping of deeper fault zones and verification of Permo-Carboniferous sediments thickness. The area has been preliminarily assessed as promising for the use of deep geothermal energy. It belongs to the south-western part of Krkonoše Piedmont Basin. The bedrock of the basin is formed by Proterozoic metamorphites. Heating of surrounding rocks by intrusions of local volcanics during the Younger Tertiary is considered important for geothermal applications. The cover of metamorphic bedrock by sediments may indicate accumulation of the heat from the bedrock at relatively shallow depths of several hundred meters. Geophysical measurements, namely reflection and refraction seismics, gravimetry and resistivity profiling identified two major fault zones of east-west and northwest-southeast direction. The interpretation of the data obtained by geophysical sounding methods, namely seismic reflection and vertical...

Thesis: M.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1980 / Includes bibliographical references. / by Akhil Gupta. / M.S. / M.S. Massachusetts Institute of Technology, Department of Mechanical Engineering

District heating is an efficient way to integrate renewable energies in the energy mix. In the French region Ile-de-France, district heating and renewables have known strong developments for several years, and they are expected to grow much more in the future. The expansion of renewable energies depends partly on their competitiveness compared to fossil fuels, which is related to public subsidies, and on the spread of district heating networks in the region. Thus, it could be assess what is the future business model for district heating based on renewables in Ile-de-France. The data at the disposal of ADEME, the French agency for environment and renewable energies, show that district heating systems based on biomass could soon become more competitive than fossil fuels, whereas systems based on geothermal heat have fairly high costs. Yet, geothermal heat is more developed than biomass, and is expected to reach the targets set by the regional action plan for 2020, on the contrary to biomass. Though the increasing competitiveness of renewables will cut the necessity of public subsidies, the difficulty to reach some regional targets might mean that further actions should be implemented. From the energy operators’ point of view, the sector of district heating will surely grow considerably and therefore represent a large potential of development for those companies.

Recent studies report rapid corrosion of metals and carbonation of minerals in contact with H2O-saturated (or nearly saturated) CO2. One explanation for this behavior is that addition of small amounts of H2O to CO2 leads to significant ionization within the fluid (analogous to corrosion in aqueous fluids). The extent of ionization in the bulk CO2 fluid was determined using a flow-through conductivity cell capable of analyzing very dilute solutions. Experiments were conducted from 25 to 200"C and 25 to 200 bar with H2O concentrations up to ~1650 ppmw. In all experiments, conductivities <10 nS/cm were obtained, indicating that the solution is essentially ion-free. This observation suggests that mobile ions are not present in the bulk CO2--rich fluid, and that the observed corrosion and carbonation reactions are not the result of ionization in the bulk fluid. / Master of Science

På grund av höga uppvärmningskostnader vill Lycksele kommun utreda de ekonomiska aspekterna av att investera i bergvärme till en fastighet som huserar vård- och omsorgsverksamhet. Fastigheten är belägen utanför Lycksele tätort vilket utesluter fjärrvärme som ett alternativ till uppvärmning. I nuläget sker uppvärmningen av fastigheten med hjälp av ett luftburet golvvärmesystem av typ Legalett som värms med elaggregat. Det huvudsakliga syftet med projektet är att avgöra om ett byte av värmesystem från direktverkande el till bergvärme är ett bra alternativ för kommunen att investera i. Genom att utföra en lönsamhetsanalys kommer lönsamheten av denna energieffektiviserande åtgärd utredas, med en förhoppning om att rapporten ska kunna hjälpa kommunen att fatta beslut angående denna typ av åtgärder även i framtiden. Genom att sammanställa fastighetsdata som samlats in med hjälp av fastighetsavdelningen på Lycksele kommun kunde fastighetens värmebehov fastställas och bergvärmesystemet dimensioneras. En varvtalsstyrd värmepump valdes för att täcka 100% av energibehovet vilket innebär ett i stort sett obefintligt behov av spetsvärme. Kostnader för bland annat borrning av bergvärme, anskaffning av värmepump samt nya vattenburna värmeaggregat beräknades och låg till grund för den lönsamhetsanalys som genomfördes. Två alternativa investeringar togs fram där skillnaden låg i värmeavgivarna. Alternativ 1 innefattar bergvärme samt anpassning av befintligt golvvärmesystem medan alternativ 2 innefattar bergvärme samt kostnader för ett nytt radiatorsystem. Uppskattningen av kostnaderna av att investera i ett nytt radiatorsystem gjordes för att ge ett alternativ som kan motverka viss problematik som upplevts med det befintliga golvvärmesystemet. Lönsamheten av de två alternativen uppskattades med hjälp av nuvärdesmetoden samt payback-metoden. Resultatet av beräkningarna innebar att kostnaden för borrning av bergvärme uppgick till ca 785 tkr, till detta tillkommer kostnaden av en värmepump, referenspumpens anskaffningsvärde var 166 tkr. Priset på nya aggregat till Legalettsystemet var 14 200 kr per aggregat. Uppskattningen av radiatorsystemets kostnad uppgick till 1,05 Mkr. Detta innebär totala investeringskostnader på just under 1,4 Mkr för alternativ 1 och på ca 2 Mkr för alternativ 2. Den lägre energianvändningen som bergvärmen möjliggör beräknades innebära ekonomiska besparingar på ca 227 tkr per år vilket innebär att payback-tiden för de två alternativens grundinvesteringar uppgår till 6,02 år för alternativ 1 och 8,8 år för alternativ 2. Då borrhålen har en längre livslängd än värmepumpen så uppskattades att värmepumpen kommer att behöva bytas två gånger under investeringens livslängd. De två alternativens nettonuvärden uppgick till ca 3,4 Mkr för alternativ 1 medan det för alternativ 2 uppgick till ca 2,7 Mkr över hela investeringens livslängd. Både nuvärdesmetoden och payback-metoden tyder på att investeringen bör vara lönsam då nettonuvärdena för de båda alternativen är positiva och payback-tiden är lägre än 20% av investeringens uppskattade livslängd. Det alternativ som ger bäst lönsamhet är alternativ 1 vilket beror på den lägre investeringskostnaden då det befintliga systemet anpassas. / Due to high heating costs, the municipality of Lycksele wants to investigate the economic aspects of investing in geothermal heating for a property that houses healthcare and care operations. The property is located outside urban area Lycksele, which excludes district heating as an alternative. At present, the property is heated by means of an air-based floor heating system of the type Legalett, which is heated by electric heaters. The main purpose of the project is to determine if a change of heating system from electrical heating to geothermal heating is a good alternative for the municipality to invest in. By conducting a profitability analysis, the profitability of the action of investing in geothermal heating will be investigated with the hope that the report will be able to help the municipality make decisions regarding these types of actions in the future. By compiling property data collected with the help of the property department of Lycksele municipality, the property's heating needs could be determined and the geothermal heating system dimensioned. An inverter-controlled ground heat pump was chosen to cover 100% of the energy demand, which means a virtually non-existent need for peak heat.  Costs for, among other things, drilling of geothermal heat, the procurement of heat pumps and new water-borne heaters were calculated and formed the basis for the profitability analysis carried out. Two alternative investment options were made where the difference were the heat emitters. Option 1 includes geothermal heating and adaptation of existing underfloor heating system, while option 2 includes geothermal heating and costs for a new radiator system. The estimate of the cost of investing in a new radiator system was made to provide an alternative that could counteract some of the problems experienced with the existing underfloor heating system. The profitability of the two alternatives was estimated using the net present value method and the payback method. The result of the calculations meant that the cost of drilling for the geothermal heat amounted to about SEK 785,000, to which the cost of a heat pump is added, the reference pump's value was SEK 166,000. The price of new units for the Legalett system was SEK 14200 per unit. The estimate of the cost of the conversion to a radiator system amounted to SEK 1.05 million. This means total investment costs of just under SEK 1.4 million for option 1 and about SEK 2 million for option 2. The lower energy consumption made possible by the geothermal heating was estimated to amount to approximately SEK 227,000 per year in economic savings, which means that the payback time for the two alternatives' basic investments is 6.02 years for options 1 and 8.8 years for option 2. Since the boreholes have a longer lifespan than the heat pump it was estimated that the heat pump will need to be replaced twice during the entire lifespan of the investment. The net present value of the two alternatives amounted to approximately SEK 3.4 million for alternative 1, while for alternative 2 it amounted to approximately SEK 2.7 million over the entire lifespan of the investment. Both the present value method and the payback method indicate that the investment should be profitable as the net present values ​​for both alternatives are positive and the payback time is less than 20% of the estimated lifespan of the investment. The alternative that provides the best profitability is option 1, which is due to the lower investment cost when adapting the existing system.

Recent awareness of the finite nature of fossil-fuel resources has resulted in an increased interest in alternate sources of energy such as geothermal. To evaluate the geothermal energy potential of the hot-springs system near Midway, Wasatch Co., Utah, consideration was given to heat flow, water chemistry, and structural controls. Abnormal heat flow was indicated qualitatively by snow-melt patterns and quantitatively by heat-flow measurements that were obtained from two of four temperature-gradient wells drilled in the area. These measurements indicated that the area north of the town of Midway is characterized by heat flow equal to 321.75 mW/m2, which is over 4 times the value generally considered as "normal" heat flow. Chemical analyses of water from six selected thermal springs and wells were used in conjunction with the silica and Na-K-Ca gethermometers to estimate the reservoir temperature of the thermal system. Because the calculated temperature was more than 25°C above the maximum observed temperature, a mixing model calculation was used to project an upper limit for the reservoir temperature. Based on these calculations, the system has a reservoir temperature ranging from 46 to 125°C. Structural information obtained from published geologic maps of the area and from an unpublished gravity survey, enabled two models to be developed for the system. The first model, based on geologic relationships in the mountains to the north and west of Midway, assumes that the heat for the thermal system comes from a relatively young intrusive or related hydrothermal convection system in the vicinity of the Mayflower mine. Meteoric waters would be heated as they approach the heat source and then move laterally to the south through faults and fractures in the rocks. These thermal waters then rise to the surface through fractures in the crest of an anticline underneath the Midway area. The second model, based on the gravity survey, assumes an igneous intrusion directly beneath Midway as the heat source. The first model is considered more likely. The Midway geothermal system is a low temperature resource, suitable for space-heating and other direct use applications.

The purpose of this study was to continue the assessment of low-temperature geothermal resources in Utah started . by the Utah Geological and Mineral Survey. The area of interest with in this report is north-central Box Elder County, Utah. Exploration techniques used included chemical analyses of water from wells and springs, temperature surveys, and temperature-depth measurements in unused wells within the study area. The highest water temperatures (31, 30, and 290c) recorded in this research were located in three separate geographic regions, suggesting that no single warm water occurrence dominates the study area. Total dissolved solid (T:DS) concentrations ranged from 294 to 11,590 mg/1. Areas of warm water occurrences generally had TDS values of greater than 1,100 mg/1. Three water types were distinguished using trilinear plots of common ion analyses of collected water samples. The warmest wells were of Type III water character, which has high (>75%) sodium and chloride concentrations. Reservoir temperatures were estimated using the water chemistry. Both the silica and the Na-K-Ca geothermometers were used to calculate reservoir temperatures, averaging between 500c and 1 ooo c. If mixing effects are taken into account, reservoir temperatures might be as high as 198°C. Temperature-depth measurements were logged in 16 unused wells. Thermal gradients calculated from the profiles ranged from isothermal to 267oC/km. The background gradient for the study area appears to be slightly above the average Basin and Range gradient of 35oC/km. The highest gradients were calculated for the area approximately 8 kilometers west of Snowville, Utah, which is also an area of warm water. Several areas of possible low-temperature geothermal interest have been identified in the study area by considering water temperatures, calculated reservoir temperatures, and temperature-depth data. However, additional work is needed to more accurately define the possible geothermal resource in these areas.

The Mountain Home (MH) geothermal system of the western Snake River Plain (SRP) magmatic province was discovered in 2012 by the Snake River Geothermal Drilling Project. Artesian flowing water with a temperature of 150°C was encountered at a depth of 1745 m below ground surface (mbgs) and extensive mineralized fracture networks of pectolite-prehnite, calcite, and laumontite were discovered in the recovered core. The objectives of this study are to: 1) describe the thermal and compositional history of past geothermal fluids, and 2) compare these fluids to modern fluids in order to characterize the evolution of the MH geothermal system and the geothermal potential of the western SRP. Core observations, thin section petrography, X-ray diffraction, and Electron Microprobe analyses were performed in order to describe mineral parageneses of various alteration zones. Carbon and oxygen stable isotope ratios along with temperatures of homogenization from fluid inclusions in hydrothermally precipitated calcite were measured along ~100 m of basalt core from 1709-1809 mbgs. The d13CPDB values in calcite range from -7.2 to -0.43 ‰ and d18OPDB values range between -20.5 and -15.9 ‰. An anomalous zone from 1722-1725 m depth displays a range in d13CPDB and d18OPDB of -1.9 to +0.88 ‰ and -17.1 to -8.1 ‰, respectively, suggesting non-equilibrium fractionation due to boiling. Carbon isotopic ratios suggest a mixture of deep-seated mantle derived and meteoric fluids. Fluid inclusion microthermometry has identified primary inclusions with trapping temperatures ranging from 168-368°C. A calcite-water geothermometer used to calculate paleo-fluid oxygen isotopic composition (-0.43 to +7.2 ‰ SMOW) and a comparison with present-day fluid oxygen isotopic composition (-3.2 ‰ SMOW) reveals a cooling trend with potential mixing of meteoric waters and deeply derived fluid. The MH geothermal system has cooled over time and reflects potentially less, if any magmatic fluid input presently into the system as there was in the past.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18937号 / 工博第3979号 / 新制||工||1613(附属図書館) / 31888 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 松岡 俊文, 教授 田村 正行, 教授 小池 克明 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18969号 / 工博第4011号 / 新制||工||1618(附属図書館) / 31920 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 小池 克明, 教授 松岡 俊文, 教授 田村 正行 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM