Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Simulation of Geothermal Energy Production Utilizing Abandoned Oil and Gas Wells(State Oil Co Azerbaijan Republic, Oil Gas Scientific Research Project inst, 2024) Mukhtarov, A. N.; Akkurt, G. E.; Yildirim, N. H.Abandoned oil and gas wells (AOGWs) with suitable reservoir temperatures present a promising opportunity to convert subsurface heat into thermal energy or electricity for various applications. This study developed a rigorous thermodynamic model for a single-flash geothermal power plant utilizing a double-pipe direct heat exchanger (DHE), leveraging data from existing literature and modeling via Engineering Equation Solver (EES) software. The model simulates the system using R134a as the working fluid, assessing the influence of rock properties, geothermal gradient, DHE geometry, insulation thickness, mass flow rate of the working fluid, and alternative working fluids on heat extraction efficiency. This innovative approach allows for the efficient utilization of available geothermal heat resources, thereby enhancing the potential for sustainable energy generation. Key findings reveal that the power generation potential from AOGWs employing DHEs is significantly affected by the geothermal gradient within the well, the length of the heat exchanger, and the thermal conductivity of the surrounding rock. Additionally, the model projects the system's long-term performance over a 20-year period, emphasizing the importance of variable fluid characteristics inside the exchanger. Overall, the simulations underscore the necessity of carefully considering these factors to optimize energy extraction from AOGWs. The results highlight the feasibility of harnessing geothermal energy in low-flow-rate conditions, ultimately contributing to the sustainability of energy resources and offering insights for future developments in geothermal energy systems. This approach not only addresses environmental concerns associated with AOGWs but also positions them as viable assets for renewable energy generation.Article Effect of Degassing on Scaling in Hypersaline System: Tuzla Geothermal Field, Turkey(Springer Science and Business Media Deutschland GmbH, 2025) Tonkul, S.; André, L.; Baba, A.; Demir, M.M.; Regenspurg, S.; Kieling, K.A serious issue with geothermal power plants is the loss of production and decline in power plant efficiency. Scaling, also known as mineral precipitation, is one of the frequently-observed issue that causes this loss and decreasing efficiency. It is heavily observed in the production wells when the geothermal fluid rises from the depths due to a change in the fluid’s physical and chemical properties. Scaling issue in geothermal power plants result in significant output losses and lower plant effectiveness. In rare instances, it might even result in the power plant being shut down. The chemistry of the geothermal fluid, non-condensable gases, pH, temperature and pressure changes in the process from production to reinjection, power plant type and design, and sometimes the materials used can also play an active role in the scaling that will occur in a geothermal system. ICP–MS was used to evaluate the chemical properties of the fluids. On the other hand, XRD, XRF and SEM were used to investigate the chemical and mineralogical compositions of the scale samples in analytical methods. For the numerical approach, PhreeqC and GWELL codes were used to follow the chemical reactivity of the geothermal fluid in Tuzla production well. The novelty of this study is to determine potential degassing point and to characterize the mineralogical assemblage formed in the well because of the fluid composition, temperature and pressure variations. During production, geothermal fluids degas in the wellbore. This causes a drastic modification of the chemistry of the Tuzla fluids. This is why it is focused the calculations on the nature of the minerals that are able to precipitate inside the well. According to simulation results, the degassing point is estimated to be about 105 m depth, consistent with the field observations. If a small quantity of precipitated minerals is predicted before the boiling point, degassing significantly changes the fluid chemistry, and the model predicts the deposition of calcite along with smaller elements including galena, barite, and quartz. The simulation results are consistent with the mineral composition of scaling collected in the well. © The Author(s) 2024.Review Citation - WoS: 26Citation - Scopus: 28Exploring Geothermal Energy Based Systems: Review From Basics To Smart Systems(Pergamon-elsevier Science Ltd, 2025) Anya, Belka; Mohammadpourfard, Mousa; Akkurt, Gulden Gokcen; Mohammadi-Ivatloo, BehnamMost of the energy demand is currently supplied from fossil fuels, which leads to the accumulation of greenhouse gases and air pollution. A sustainable future can be created globally through the efficient use of renewable energy sources. These sources include wind, solar, geothermal, biomass, and more. Geothermal energy can meet the energy needs of the future as a clean and reliable source and stands out due to certain distinctive features among renewable energy sources. Unlike other renewable energy sources, geothermal energy is not dependent on time or weather, making it a reliable and continuous energy supply. Additionally, it has a lower environmental impact. This review examines the development of geothermal energy systems and their integration into smart technologies, highlighting the potential of geothermal energy for smart energy systems. The focus is on integrating smart systems into geothermal-based setups to enhance efficiency and analyze the state-of-the-art technologies of such systems. Geothermal-based systems can be classified as single generation, co-generation, multigeneration, smart energy systems, and energy hubs. Consequent to examining systems, it has been concluded that geothermal systems have a huge potential, but unfortunately, not all of them are used due to some difficulties. Its development will occur faster, and its share in the renewable energy sector will grow with smart system integration.Article Citation - Scopus: 3A Brief Overview on Geothermal Scaling(General Directorate of Mineral Research and Exploration (MTA), 2023) Isık, Tuğba; Baba, Alper; Chandrasekharam, Dornadula; Demir, Mustafa M.; Isık, Tuğba; Baba, Alper; Demir, Mustafa MuammerHot spring waters are rich in terms of minerals. Since there are dramatic changes in thermodynamic parameters in geothermal power plants, such as a decrease in temperature and pressure, severe precipitation occurs throughout the system components in an uncontrolled manner. There are three main chemistries in deposits: carbonates (mainly calcium carbonates), silicates (metal silicates), and sulphides (antimony sulphide-stibnite). Energy harvesting is remarkably reduced out of the insulating nature of the deposit. Various actions need to be taken to mitigate this undesirable issue of scaling in geothermal systems. Geothermal systems are in fact quite complex, and the composition of brine and, accordingly, the chemistry of the deposit are not identical. Therefore, each system should be studied individually, and a tailor-made remedy should be developed. In this overview, the types of deposits in terms of chemistry and the actions (pH modification or antiscalant dosing) that should be taken to reduce scaling are mentioned, and potential chemistries of antiscalants are given.Article Citation - WoS: 8Citation - Scopus: 8Structural Controls and Hydrogeochemical Properties of Geothermal Fields in the Varto(TÜBİTAK Scientific & Technological Research Council Turkey, 2021) Uzelli, Taygun; Sener, Mehmet Furkan; Dolek, Iskender; Baba, Alper; Sozbilir, Hasan; Dirik, Ramazan KadirVarto and the surrounding region have important geothermal fields, developing in strike-slip tectonic setting in East Anatolia, which resulted from the collision of the Arabian and Eurasian plates. The main structural elements in the area are the NE-trending sinistral and NW-trending dextral strike-slip fault segments and N-S trending extension zones. In order to determine fault-controlled geothermal circulation, it is very important to fully characterize the structural elements in these complex environments. The widely distributed volcanic rocks have fracture and crack systems that play an important role in surface infiltration, geothermal fluid, and groundwater circulation. Especially in areas where the fault segments intersect, hot springs outlets and natural resources easily come to the surface. In order to understand the flow paths of geothermal fluid along the faults in these geothermal systems, it is necessary to determine the stress state of the faults and to map the distribution of the structural elements. For this reason, we conducted a detailed study on the Varto Fault Zone, which has important geothermal fields in Eastern Anatolia. We present conceptual models of the geothermal fields in the Varto region that show favorable geothermal activity on the intersecting fault segments, fault bends, step-overs, and accompanying fracture-crack sets. As a result, we emphasize that the planes of strike-slip faults in transtensional areas are more favorable for secondary permeability and enhances the geothermal fluid circulation, and this can be supported by hydrogeochemical data.