Elemental Distribution and Partitioning Law between the Geothermal Water and Associated Deposits for a Typical Geothermal System with Large-Scale Siliceous Sinter Deposits in the Tibet

2021 ◽  
Author(s):  
Hartman Issombo Elenga ◽  
Hongbing Tan ◽  
Dongpin Shi ◽  
Djohn Josia Weaver Mboussa
Keyword(s):  
Large Scale ◽  
Geothermal Water ◽  
Geothermal System ◽  
Elemental Distribution ◽  
Siliceous Sinter

EASYGO - Efficiency and Safety in Geothermal Operations – A new Innovative Training Network

2021 ◽  
Author(s):  
Maren Brehme ◽  
Martin O Saar ◽  
Evert Slob ◽  
Paola Bombarda ◽  
Hansruedi Maurer ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Strategic Alliance ◽  
Early Stage ◽  
Energy Transition ◽  
Geothermal System ◽  
Geothermal Systems ◽  
Operational Parameters ◽  
European Universities ◽  
Research Profile

<p>How to operate a geothermal system in the most efficient and safe manner? This is the most important and urgent question after a geothermal resource has been identified. The recently funded Innovative Training Network ‘EASYGO‘ will answer that question from different perspectives and give high-level training for early stage researchers (ESR; here PhD candidates) in geothermal operations.</p><p>Tackling the challenges of sustainable geothermal operations requires an interdisciplinary and intersectoral approach. To achieve the main objective, researchers will work on the whole chain of geothermal operations, from production to power-plant engineering to injection. They will develop novel monitoring concepts, perform real-time simulations, develop system components, assess novel concepts for operations and test operational parameters at the field scale. The major strength and originality of the programme is that it is developed around large-scale infrastructure. Researchers will have access to the infrastructure in all countries for testing equipment and doing real-time measurements.</p><p>EASYGO graduates will be a new generation of multidisciplinary experts in geothermal operations, trained to achieve standardised efficient and safe operations of geothermal systems to enable the ambitious international expansion plans. The mobility plan of EASYGO envisages each ESR to have at least one academic secondment and one industrial secondment.</p><p>EASYGO consists of an intersectoral team of experts from academic and non-academic institutions. All academic participants are members of the IDEA League, a strategic alliance of leading European universities of technology. The members of the IDEA League with a strong research profile in geothermal energy, TU Delft (The Netherlands), RWTH Aachen (Germany), ETH Zurich (Switzerland) and Politecnico di Milano (Italy), constitute the academic consortium of EASYGO. Additionally, ten industry partners from all countries drive the research from an applied point of view. Our ambition is to contribute to making Europe a world leader in geothermal science, operational technology and education, thereby accelerating the energy transition.</p>

scholarly journals Hydrogeochemical Characteristics and Genesis of Geothermal Water from the Ganzi Geothermal Field, Eastern Tibetan Plateau

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1631
Author(s):  
Fan ◽  
Pang ◽  
Liao ◽  
Tian ◽  
Hao ◽  
...  
Keyword(s):  
High Temperature ◽  
Tibetan Plateau ◽  
Heat Source ◽  
Chloride Concentration ◽  
Geothermal Field ◽  
Geothermal Water ◽  
Helium Isotope ◽  
Geothermal System ◽  
The Tibetan Plateau ◽  
Geothermal Waters

The Ganzi geothermal field, located in the eastern sector of the Himalayan geothermal belt, is full of high-temperature surface manifestations. However, the geothermal potential has not been assessed so far. The hydrochemical and gas isotopic characteristics have been investigated in this study to determine the geochemical processes involved in the formation of the geothermal water. On the basis of δ18O and δD values, the geothermal waters originate from snow and glacier melt water. The water chemistry type is dominated by HCO3-Na, which is mainly derived from water-CO2-silicate interactions, as also indicated by the 87Sr/86Sr ratios (0.714098–0.716888). Based on Cl-enthalpy mixing model, the chloride concentration of the deep geothermal fluid is 37 mg/L, which is lower than that of the existing magmatic heat source area. The estimated reservoir temperature ranges from 180–210 °C. Carbon isotope data demonstrate that the CO2 mainly originates from marine limestone metamorphism, with a fraction of 74–86%. The helium isotope ratio is 0.17–0.39 Ra, indicating that the He mainly comes from atmospheric and crustal sources, and no more than 5% comes from a mantle source. According to this evidence, we propose that there is no magmatic heat source below the Ganzi geothermal field, making it a distinctive type of high-temperature geothermal system on the Tibetan Plateau.

scholarly journals Synthesis of geochemical techniques to identify the origin and multistage evolution of saline water in a complex geothermal system

2019 ◽  
Vol 98 ◽  
pp. 08005 ◽  
Author(s):  
Yinlei Hao ◽  
Zhonghe Pang ◽  
Tianming Huang ◽  
Yanlong Kong ◽  
Jiao Tian ◽  
...  
Keyword(s):  
Early Stage ◽  
Saline Water ◽  
Eastern China ◽  
Sulfide Oxidation ◽  
Geothermal Water ◽  
Shallow Aquifer ◽  
Geothermal System ◽  
Geothermal Systems ◽  
Origin And Evolution ◽  
A Minor

Elucidating brine origin and evolution is a fundamental but not easy task especially for coastal geothermal systems with possible marine constituents and multistage evolution, as subsequently physical, chemical and biological alteration processes may mask the original and early-stage signatures. Here chemical and isotopic characteristics of water (D and 18O) and dissolved constituents (13C, 14C, 11B and 87Sr/86Sr) have been utilized to investigate the source and multistage evolution of the Jimo coastal geothermal system in eastern China, with dramatic differences of geochemical characteristics observed within a 0.2 km2 area. Results show that geothermal water is derived from paleo-meteoric water and has undergone a 3-stages evolution that involves: (1) Dissolution of marine halite and potash salts in the deep reservoir; (2) Water-rock reactions especially cation exchange produces a Cl-Na-Ca type water as deep geothermal water upwells along the fault zone; (3) A minor (<0.3%) addition of fossil seawater to the shallow aquifer that produces Cl-Na type waters in the west, whereas sulfide oxidation and dissolution of aluminosilicate and carbonates in the east produces Cl-Na-Ca type waters. The methodology utilized in this study offers a means of examining other similar complex geochemical systems having a multistage evolution.

scholarly journals Ecosystem-bedrock interaction changes nutrient compartmentalization during early oxidative weathering

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dragos G. Zaharescu ◽  
Carmen I. Burghelea ◽  
Katerina Dontsova ◽  
Jennifer K. Presler ◽  
Edward A. Hunt ◽  
...  
Keyword(s):  
Large Scale ◽  
Distribution Patterns ◽  
Major Elements ◽  
Mineral Dissolution ◽  
Elemental Distribution ◽  
Quantitative Evidence ◽  
Relative Contribution ◽  
Evolutionary Innovation ◽  
Biogeochemical Models ◽  
Abiotic Controls

Abstract Ecosystem-bedrock interactions power the biogeochemical cycles of Earth’s shallow crust, supporting life, stimulating substrate transformation, and spurring evolutionary innovation. While oxidative processes have dominated half of terrestrial history, the relative contribution of the biosphere and its chemical fingerprints on Earth’s developing regolith are still poorly constrained. Here, we report results from a two-year incipient weathering experiment. We found that the mass release and compartmentalization of major elements during weathering of granite, rhyolite, schist and basalt was rock-specific and regulated by ecosystem components. A tight interplay between physiological needs of different biota, mineral dissolution rates, and substrate nutrient availability resulted in intricate elemental distribution patterns. Biota accelerated CO2 mineralization over abiotic controls as ecosystem complexity increased, and significantly modified the stoichiometry of mobilized elements. Microbial and fungal components inhibited element leaching (23.4% and 7%), while plants increased leaching and biomass retention by 63.4%. All biota left comparable biosignatures in the dissolved weathering products. Nevertheless, the magnitude and allocation of weathered fractions under abiotic and biotic treatments provide quantitative evidence for the role of major biosphere components in the evolution of upper continental crust, presenting critical information for large-scale biogeochemical models and for the search for stable in situ biosignatures beyond Earth.

scholarly journals Investigation of the Rotokawa Geothermal System and Feasibility of Supercritical Fluid Production within the TVZ through Supercritical TOUGH2 Numerical Modeling.

2021 ◽  
Author(s):  
◽  
Benjamin Carson
Keyword(s):  
Supercritical Fluid ◽  
Process Model ◽  
Large Scale ◽  
Numerical Models ◽  
Natural State ◽  
Geothermal System ◽  
Convection Flow ◽  
Fixed Temperature ◽  
Single Fault ◽  
Brittle Ductile Transition

<p>A single fault process model was created to test the sensitivity of each TOUGH2 rock parameter on the convection flow rate and fluid enthalpy within a simulated fault. With a fixed temperature base the single fault process model found a negative correlation with the fault permeability and convection fluid enthalpy and a positive liner increases in mass flow with fault area.  Next a large scale Supercritical TOUGH2 model was built to simulate the entire Rotokawa geothermal system incorporating findings of the fault process model. The single porosity model 20 x 10 x 6km with 20 layers and 57,600 grid blocks. Unlike previous models of the Rotokawa reservoir and larger scale TVZ numerical models a fixed temperature base with a no flow boundary was used to represent the brittle ductile transition. The model permeability below the currently explored reservoir was bounded by 3-D magnetologic data. Lower resistivity zones were given higher bulk permeability in the model.  The model resulted in a comparable temperature and pressure match to the Rotokawa natural state conditions. Convection of supercritical fluid reached depths shallower than -4500mRL but only occurred in zones with a bulk vertical permeability less than 2 mD. Further modelling work with a supercritical wellbore coupled reservoir model will be need to evaluate the potential deliverability of a super critical well from the Rotokawa geothermal system.</p>

Geophysical investigations of the Cove Fort‐Sulphurdale geothermal system, Utah

Geophysics ◽  
1985 ◽  
Vol 50 (11) ◽  
pp. 1732-1745 ◽  
Author(s):  
Howard P. Ross ◽  
Joseph N. Moore
Keyword(s):  
High Temperature ◽  
Large Scale ◽  
Thermal Anomaly ◽  
Power Production ◽  
Time Frame ◽  
Geothermal Reservoir ◽  
Magnetic Data ◽  
Geothermal System ◽  
Thermal Anomalies ◽  
Geothermal Fluids

The Cove Fort‐Sulphurdale KGRA is part of one of the largest thermal anomalies in the western United States. Since 1975 an extensive data base has been developed which includes the results of detailed and regional geologic, gravity, magnetic, seismic, and resistivity investigations. Geologic studies have delineated the major tectonic elements of the thermal system and have led to the recognition of large‐scale gravitational glide blocks that act as a leaky cap to portions of the geothermal system. Gravity and magnetic data have delineated major throughgoing structures beneath alluvium and basalt cover, and have indicated the importance of the Cove Fort‐Beaver graben in localizing the geothermal reservoir. The presence of these structures and a high level of microearthquake activity suggest other target areas within the larger thermal anomaly. Electrical resistivity surveys and thermal gradient holes both contribute to the delineation of the known reservoir. Four deep exploration wells which test the geothermal system were drilled between 1975 and 1979. One well, CFSU 42–7, recorded temperatures of 178°C. The high cost of drilling, high corrosion rates, low reservoir pressures, and the apparent limited extent of the high‐temperature reservoir led to a premature conclusion in 1980 that the field was not economic for large‐scale electric power production. More recent drilling in the vicinity of CFSU 42–7 resulted in the discovery of high‐temperature (200°C?) geothermal fluids at a depth of approximately 350 m. A well‐head generator was installed and power production is expected in 1985. Additional development of the geothermal reservoir is anticipated in the 1985 to 1987 time frame.

Regional structures influencing the groundwater geochemistry around geothermal springs: A case study from Padiyathalawa, Sri Lanka

2021 ◽  
Author(s):  
Dilshan Bandara ◽  
Thomas Heinze ◽  
Mahinda Premathilake ◽  
Stefan Wohnlich
Keyword(s):  
Sri Lanka ◽  
Hot Spring ◽  
Tectonic Setting ◽  
Shallow Groundwater ◽  
Shear Zones ◽  
Geothermal Water ◽  
Geothermal System ◽  
Flow Paths ◽  
Geothermal Springs ◽  
Distribution Maps

&lt;p&gt;Hydro-geochemistry of groundwater plays an important role in understanding the characteristics of a geothermal system. Mixing zones of geothermal deep waters and shallow groundwater can be identified through chemical distribution maps and help identify geothermal flow paths. The flow paths can be used to calculate the chemical values of the geothermal water leading to a characterization of the heat source. In combination with knowledge about regional structures, the geochemical distribution can further reveal unknown geothermal zones.&lt;/p&gt;&lt;p&gt;In the present study, the geochemical distribution of the groundwater is studied from samples collected from shallow and deep wells, with special reference to the regional structures present in the terrain. The study area was selected as a 20 &amp;#8226; 20 km area centered around the Padiyathalawa hot spring field in Sri Lanka. From the results, two main geochemical anomalous zones are identified, especially with the increased values of electrical conductivity (EC), total dissolved solids (TDS), and Sulphate distribution maps. Those two zones include the hot spring itself as well as an area in ~10 km distance in the NE direction from the hot spring. Both zones are characterized by crosscutting structures of dolerite dykes and shear zones. Due to the shear zones, there are deep-seated fractures facilitating water flow from deeper layers towards the surface. This uprising water mixes with the shallow groundwater, affecting the general geochemical values of the shallow groundwater system.&lt;/p&gt;&lt;p&gt;Common minerals in Dolerite in Sri Lanka are Pyroxenes, Feldspar, Ilmenite, Magnetite, and Pyrite with minor amounts of other minerals. The increased EC values in both before mentioned zones relate with higher amounts of iron due to dissolution and mixing processes in regions with fractured Dolerite. Similarly, the increased concentration of Sulphates in the groundwater can be related to Pyrite from the fractured Dolerite, as microbial oxidization of Pyrite leads to origin of Sulphates. The increase of TDS can be interpreted as shallow water mixing with deep geothermal water, which contains a higher amount of minerals from the fractured dolerites.&lt;/p&gt;&lt;p&gt;The similar geochemical anomalies in those two zones can be associated with cross-cutting Dolerite dikes and existing faults in the shear zones at greater depth, subsequently mixing uprising deep geothermal water with shallow groundwater. A similar geochemistry and tectonic setting suggest similar flow paths from the underground and therefore also similar geothermal conditions at both spots. However, due to the rural and remote region, only one of the two before mentioned areas is known as a hot spring field. Thermal signatures dissipate much more quickly in the shallow groundwater than the mineral composition and might not be significant for measurement. Geochemical signatures of groundwater can therefore be a substantial help to locate geothermal springs, identify source mechanisms and characterize fluid flow paths.&lt;/p&gt;

scholarly journals 3D Convolution Conjugate Gradient Inversion of Potential Fields in Acoculco Geothermal Prospect, Mexico

2022 ◽  
Vol 9 ◽  
Author(s):  
José P. Calderón ◽  
Luis A. Gallardo
Keyword(s):  
Conjugate Gradient ◽  
Potential Field ◽  
Field Data ◽  
Large Scale ◽  
Three Dimensional ◽  
Potential Fields ◽  
Magnetic Data ◽  
Geothermal System ◽  
Potential Field Data ◽  
Model Compression

Potential field data have long been used in geophysical exploration for archeological, mineral, and reservoir targets. For all these targets, the increased search of highly detailed three-dimensional subsurface volumes has also promoted the recollection of high-density contrast data sets. While there are several approaches to handle these large-scale inverse problems, most of them rely on either the extensive use of high-performance computing architectures or data-model compression strategies that may sacrifice some level of model resolution. We posit that the superposition and convolutional properties of the potential fields can be easily used to compress the information needed for data inversion and also to reduce significantly redundant mathematical computations. For this, we developed a convolution-based conjugate gradient 3D inversion algorithm for the most common types of potential field data. We demonstrate the performance of the algorithm using a resolution test and a synthetic experiment. We then apply our algorithm to gravity and magnetic data for a geothermal prospect in the Acoculco caldera in Mexico. The resulting three-dimensional model meaningfully determined the distribution of the existent volcanic infill in the caldera as well as the interrelation of various intrusions in the basement of the area. We propose that these intrusive bodies play an important role either as a low-permeability host of the heated fluid or as the heat source for the potential development of an enhanced geothermal system.

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