scholarly journals Proposal of a consistent framework to integrate geothermal potential classification with energy extraction

2015 ◽  
Vol 3 (1) ◽  
pp. 7-11 ◽  
Author(s):  
G. Falcone
Keyword(s):  
Geothermal Energy ◽  
Development Projects ◽  
Energy Extraction ◽  
Assessment Methodology ◽  
Geothermal Resources ◽  
Classification Schemes ◽  
Geothermal Potential ◽  
Different Levels

<p><strong>Abstract.</strong> The classification of geothermal resources is dependent on the estimate of their corresponding geothermal potential, so adopting a common assessment methodology would greatly benefit operators, investors, government regulators and consumers. <br><br> Several geothermal classification schemes have been proposed, but, to date, no universally recognised standard exists. This is due to the difficulty in standardising fundamentally different geothermal source and product types. The situation is not helped by the accepted use of inconsistent jargon among the geothermal community. In fact, the term "geothermal potential" is often interpreted differently by different geothermal practitioners. <br><br> This paper highlights the importance of integrating the classification of geothermal potential with that of geothermal energy extraction from well-defined development projects. A structured progression, from estimates of in situ quantities for a given prospect to actual production, is needed. Employing a unique, unambiguous framework would ensure that the same resource cannot exist simultaneously under different levels of maturity of the estimate (as in double bookings of resources), which would let stakeholders better assess the level of risk involved and the steps needed for a geothermal potential to achieve commercial extraction.</p>

scholarly journals Geothermal Power Production from Abandoned Oil Reservoirs Using In Situ Combustion Technology

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4476 ◽  
Author(s):  
Yuhao Zhu ◽  
Kewen Li ◽  
Changwei Liu ◽  
Mahlalela Bhekumuzi Mgijimi
Keyword(s):  
Geothermal Energy ◽  
Economic Benefits ◽  
Payback Period ◽  
Oil Reservoirs ◽  
Oil Reservoir ◽  
Outlet Temperature ◽  
Geothermal Resources ◽  
In Situ Combustion ◽  
Combustion Technology

Development of geothermal resources on abandoned oil reservoirs is considered environmentally friendly. This method could reduce the rate of energy consumption from oil fields. In this study, the feasibility of geothermal energy recovery based on a deep borehole heat exchanger modified from abandoned oil reservoirs using in situ combustion technology is investigated. This system could produce a large amount of heat compensated by in situ combustion in oil reservoir without directly contacting the formation fluid and affecting the oil production. A coupling strategy between the heat exchange system and the oil reservoir was developed to help avoid the high computational cost while ensuring computational accuracy. Several computational scenarios were performed, and results were obtained and analyzed. The computational results showed that an optimal water injection velocity of 0.06 m/s provides a highest outlet temperature of (165.8 °C) and the greatest power output of (164.6 kW) for a single well in all the performed scenarios. Based on the findings of this study, a geothermal energy production system associated with in situ combustion is proposed, specifically for economic reasons, because it can rapidly shorten the payback period of the upfront costs. Modeling was also performed, and based on the modeling data, the proposed technology has a very short payback period of about 4.5 years and a final cumulative net cash flow of about $4.94 million. In conclusion, the present study demonstrates that utilizing geothermal resources or thermal energy in oilfields by adopting in situ combustion technology for enhanced oil recovery is of great significance and has great economic benefits.

scholarly journals Geothermal potential, chemical characteristic and utilization of groundwater in Serbia

2021 ◽  
Author(s):  
Tanja Petrović Pantić ◽  
Katarina Atanasković Samolov ◽  
Jana Štrbački ◽  
Milan Tomić
Keyword(s):  
Geothermal Energy ◽  
Thermal Water ◽  
Pannonian Basin ◽  
Local Population ◽  
Hydrochemical Facies ◽  
Energy Utilization ◽  
Thermal Waters ◽  
Groundwater Temperature ◽  
Geothermal Resources ◽  
Geothermal Potential

Abstract In order to collect and unify data about all geothermal resources in Serbia, a database is formed. The database allows us to perceive the geothermal resources of Serbia and their potential for utilization. Based on the data available in the geothermal database, the estimated temperatures of reservoirs, heat power, and geothermal energy utilization were calculated. The database contains 293 objects (springs, boreholes) registered at 160 locations with groundwater temperature in the range between 20°C and 111°C. The maximum expected temperature of the reservoir is 146°C (according to the SiO2 geothermometer). Some thermal water is cooled while mixed with cold, shallow water. Geothermal resources are mostly used for balneology and recreation, and less for heating, water supply, bottling, fish and animal farms, agriculture, and technical water. 26% of all geothermal resources is used by the local population or has not been used at all. The annual utilization of geothermal energy for direct heat is 1507 TJ/yr, and the estimated capacity of geothermal energy in Serbia is 111 MWt. The results of analytical work were presented in the form of maps with a geological and hydrogeological background. Thermal waters are mostly registrated in the area of Tertiary magmatism. The three geothermal potential areas are identified: Pannonian basin-Vojvodina Province, Mačva-Srem and area from Jošanička Banja to Vranjska Banja (southern Serbia). Based on chemical analyses, four hydrochemical facies are distinguished. Thermal water mainly belongs to NaHCO3 or CaMgHCO3 hydrochemical facies, usually depending on the primary aquifer: karst, karst-fissured, intergranular or fissured.

Shallow Geothermal Resources Assessment of the Brussels Region: Exploration, 3D Geological Model, Geothermal Potential Mapping and Challenges Related

2020 ◽  
Author(s):  
Estelle Petitclerc ◽  
Pierre Gerard ◽  
Xavier Devleeschouwer ◽  
Bertrand François ◽  
Marijke Huysmans ◽  
...  
Keyword(s):  
Geothermal Energy ◽  
Public Awareness ◽  
Design Tool ◽  
Geological Model ◽  
Geothermal Systems ◽  
Geothermal Resources ◽  
Development Fund ◽  
3D Geological Model ◽  
Geothermal Potential ◽  
Geothermal Parameters

&lt;p&gt;In 2015, a legal framework was implemented in the Brussels-Capital Region (BCR) where passive construction has been mandatory with an obliged heat demand not exceeding 15 kW&lt;sub&gt;h&lt;/sub&gt;/m&lt;sup&gt;2&lt;/sup&gt;. Since 2015, the interest in installing shallow geothermal systems has significantly increased. However, limited knowledge of ground conditions, lack of public awareness and the urban nature of the Brussels area restrict the development of shallow geothermal systems despite the high potential of this technique in the RBC. The BRUGEO project aims to facilitate accessibility and the efficient use of shallow geothermal energy in the BCR specifically for commercial and residential sectors. Thanks to Brussels ERDF (European Regional Development Fund) funding a consortium of all major actors in geothermal energy were brought together (ULB, Brussels Environment, BBRI, VUB, and GSB). During the &amp;#160;four years project (2016-2020), specific actions promoting the geothermal potential were addressed: 1- Collect existing data related to the knowledge on Brussels subsurface (geological, hydrogeological, and geothermal data) and consolidate them in a single database; 2- Conduct new laboratory and field tests in order to complete geological analyses and to assess geothermal parameters; 3- Map the geothermal potential for open and closed systems. The Geological Survey of Belgium (GSB) has created, during the last 7 years, a GIS based 2D-3D geological model of the BCR underground. 9266 drillings and geotechnical data collected in and around the BCR have been used to create the Brustrati3D model generating interpolated top and base surfaces for 19 geological layers representing the whole lithostratigraphic sequence from Quaternary to the Paleozoic basement. An important exploration phase was included in the first two years of the BRUGEO project to acquire new data improving the geological and hydrogeological knowledge of BCR. Several in-situ parameters are measured by e.g. new piezometers implementation and monitoring, pumping tests, cores sampling, logging and enhanced thermal response tests (eTRT). These measurements are implemented as far as possible on future private projects by a win-win approach. The idea is to be grafted on existing projects to increase the data acquisition and to avoid purely exploratory drilling that are expensive and not used later for any geothermal exploitation. So far, the BRUGEO consortium has also conducted three exploration drillings to assess the lithology, the structure, the groundwater flows, and geophysical properties of the Cambrian basement (Brabant Massif). In parallel, laboratory measurements are achieved to characterize the determinant thermal parameters of the Brussels underground. From all the subsurface data collected, the BRUGEO consortium aims at mapping the geothermal potential of the BCR. This web-based mapping, accessible to design offices, installers of geothermal systems, citizens, public and private stakeholders or regional and municipalities administrations, will make it easier to foster the use of geothermal energy. The web portal will consist of an interactive decision support and a design tool based on maps built thanks to the geoscientific 3D models and geothermal parameters assessed during BRUGEO. The results are expected to be published online in March 2020.&lt;/p&gt;

Characterisation of the Dogger and Trias deep ressources in Orléans Métropolis, Centre-Val de Loire region, France : 3D geomodel and first geothermal potential assessment

2021 ◽  
Author(s):  
Virginie Hamm ◽  
Laure Capar ◽  
Perrine Mas ◽  
Philippe Calcagno ◽  
Séverine Caritg-Monnot
Keyword(s):  
Seismic Data ◽  
Geothermal Energy ◽  
District Heating ◽  
Geological Model ◽  
Paris Basin ◽  
Reservoir Properties ◽  
Geothermal Resources ◽  
Geothermal Well ◽  
Geothermal Potential ◽  
Heating Networks

&lt;p&gt;In Ile-de-France region, in the center of Paris Basin, geothermal energy contributes to a large extent to the supply of heating networks with about 50 of the 70 deep geothermal installations dedicated to district heating in France. Those installations mainly exploit the Dogger limestones between 1500-2000 m deep, which are present throughout the Paris Basin. In the case of Centre Val-de Loire region, south of Paris Basin, deep geothermal energy is very little developed, only one geothermal well is currently in operation and targeting the Triassic aquifer at Chateauroux on the southern edge of the basin. A former doublet had also targeted the Trias at Melleray (Orl&amp;#233;ans metropolis) in the 1980&amp;#8217;s but was shut down after one year due to reinjection problem.&lt;/p&gt;&lt;p&gt;In 2019, Orl&amp;#233;ans metropolis, in collaboration with BRGM, has launched a program in order to investigate its deep geothermal resources like the Dogger and Trias aquifers between 900 m and 1500 m deep. This action is in line with Orl&amp;#233;ans m&amp;#233;tropolis Territorial Climate Air Energy Plan (PCAET) and master plan for the heating networks adopted which foresee 65 000 additional dwellings to be connected using geothermal energy based heating networks.&lt;/p&gt;&lt;p&gt;In order to reduce the risks of failure of deep geothermal drilling, one of the prerequisites is a better knowledge of the subsurface. This requires the development of an accurate 3D subsurface geomodel as well as the most reliable possible hydrodynamic and thermal parameters to assess the geothermal potential. The purpose of this work was to produce a 3D geological model of the Dogger and Triassic units, on the scale of Orl&amp;#233;ans Metropolis, based on hydrocarbon and geothermal well data as well as interpretation of 2D seismic data. Seismic data acquired in the 1960s and the 1980s were processed and interpreted. A particular attention was paid to the Sennely fault and its geometry. It crosses the study area and was interpreted as a relay fault segmented in three parts. The horizon picking points were then converted from two-way time to depth and integrated in the GeoModeller software for the development of the 3D geomodel. It was then used for first hydrothermal simulations in order to assess the theorical potential of the Dogger and Trias aquifers at Orl&amp;#233;ans metropolis.&lt;/p&gt;&lt;p&gt;The 3D geomodel and first geothermal potential assessment have allowed defining areas of interest for geothermal development into the Dogger or Trias. However an initial exploratory drilling well or additional exploration techniques will be necessary to confirm/specify the reservoir properties (useful thickness, porosity, permeability) and the connectivity of the reservoir(s) and the flow rates that can actually be exploited, which cannot be predicted by the current geological model.&lt;/p&gt;

scholarly journals Geothermal Energy Development in East Africa: Barriers and Strategies

2018 ◽  
pp. 1-6 ◽  
Author(s):  
Emmanuel Yeri Kombe ◽  
Joseph Muguthu
Keyword(s):  
East Africa ◽  
Geothermal Energy ◽  
Electricity Generation ◽  
Early Stage ◽  
East African ◽  
African Countries ◽  
Geothermal Resources ◽  
Resource Potential ◽  
Geothermal Potential ◽  
African Rift

The East African Rift is among the most crucial regions of the world endowed with a remarkable geothermal potential. Using current technologies, East African countries have a geothermal power potential of more than 15,000 MWe. Nevertheless, the zone is still at an early stage of geothermal development with few plants producing a few hundred MWe. Among East African countries that have carried out research on geothermal resources, Kenya is leading in utilising geothermal energy resources for electricity generation. Eritrea, Uganda, Tanzania and Djibouti are at exploration stage while Malawi and Rwanda have so far not gone past geothermal resource potential record work. This study sought to address the challenges and barriers to the adoption of geothermal energy as well as the strategies to implement geothermal energy plans in East Africa.

scholarly journals Temperature Distribution and Heat Flow Density Estimation in Geothermal Areas of Absheron Peninsula

2020 ◽  
Vol 3 (1) ◽  
pp. 26-31
Author(s):  
Aygun Vahid Mammadova
Keyword(s):  
Heat Flow ◽  
Geothermal Energy ◽  
Geothermal Gradient ◽  
Geothermal Field ◽  
Flow Density ◽  
Geothermal Resources ◽  
Deep Wells ◽  
Recoverable Resources ◽  
Middle Pliocene

Geothermal field of the Pliocene complex in the Absheron peninsula, Azerbaijan have been examined on the basis of temperature distributions in over 50 deep wells. Data analysis include variations in geothermal gradient and distribution of heat flow within complexes of Absheron formation of upper Pliocene in age. Geothermal gradients are in the range of 17 to 25oC/km. The heat flow values are found to fall in the range of 50 to 80mW/m2. Estimates have been made of geothermal energy resources up to depths of 6000 meters. The main productive strata are of middle Pliocene in age. The results have allowed identification of geothermal resources with temperature above the 20°C and at depths less than 110-180 meters. Assessments of in-situ and recoverable resources have been made for 21 sites. Model simulations point to perspectives for widespread utilization of geothermal energy in the Absheron peninsula.

Mechanical behaviour of Australian Strathbogie granite under in-situ stress and temperature conditions: An application to geothermal energy extraction

Geothermics ◽  
2017 ◽  
Vol 65 ◽  
pp. 44-59 ◽  
Author(s):  
W.G.P. Kumari ◽  
P.G. Ranjith ◽  
M.S.A. Perera ◽  
S. Shao ◽  
B.K. Chen ◽  
...  
Keyword(s):  
Mechanical Behaviour ◽  
Geothermal Energy ◽  
In Situ Stress ◽  
Energy Extraction ◽  
Temperature Conditions

scholarly journals Classification of geothermal resources by potential

2015 ◽  
Vol 3 (1) ◽  
pp. 13-17 ◽  
Author(s):  
L. Rybach
Keyword(s):  
Energy Resources ◽  
Economic Potential ◽  
Renewable Energy Resources ◽  
Geothermal Resources ◽  
Economic Resource ◽  
Geothermal Potential ◽  
Technical Potential ◽  
Available Technology

<p><strong>Abstract.</strong> When considering and reporting resources, the term "geothermal potential" is often used without clearly stating what kind of potential is meant. For renewable energy resources it is nowadays common to use different potentials: theoretical, technical, economic, sustainable, developable – decreasing successively in size. In such a sequence, the potentials are progressively realizable and more and more rewarding financially. The theoretical potential describes the physically present energy, the technical potential the fraction of this energy that can be used by currently available technology and the economic potential the time- and location-dependent fraction of the previous category; the sustainable potential constrains the fraction of the economic potential that can be utilized in the long term; the developable potential is the fraction of the economic resource which can be developed under realistic conditions. In converting theoretical to technical potential, the recovery factor (the ratio extractable heat/heat present at depth) is of key importance. An example (global geothermal resources) is given, with numerical values of the various potentials. The proposed classification could and should be used as a kind of general template for future geothermal energy resources reporting.</p>

Development and Evaluation of Fuzzy Criteria for the Diagnosis of Rheumatoid Arthritis

1996 ◽  
Vol 35 (04/05) ◽  
pp. 334-342 ◽  
Author(s):  
K.-P. Adlassnig ◽  
G. Kolarz ◽  
H. Leitich
Keyword(s):  
Rheumatoid Arthritis ◽  
Reference Model ◽  
American Rheumatism Association ◽  
Uniform Definition ◽  
Sensitivity Rate ◽  
Fuzzy Techniques ◽  
Definition Of ◽  
Different Levels ◽  
Specificity Rate

Abstract:In 1987, the American Rheumatism Association issued a set of criteria for the classification of rheumatoid arthritis (RA) to provide a uniform definition of RA patients. Fuzzy set theory and fuzzy logic were used to transform this set of criteria into a diagnostic tool that offers diagnoses at different levels of confidence: a definite level, which was consistent with the original criteria definition, as well as several possible and superdefinite levels. Two fuzzy models and a reference model which provided results at a definite level only were applied to 292 clinical cases from a hospital for rheumatic diseases. At the definite level, all models yielded a sensitivity rate of 72.6% and a specificity rate of 87.0%. Sensitivity and specificity rates at the possible levels ranged from 73.3% to 85.6% and from 83.6% to 87.0%. At the superdefinite levels, sensitivity rates ranged from 39.0% to 63.7% and specificity rates from 90.4% to 95.2%. Fuzzy techniques were helpful to add flexibility to preexisting diagnostic criteria in order to obtain diagnoses at the desired level of confidence.

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