LEE- Jeofizik Mühendisliği Lisansüstü Programı

Bu topluluk için Kalıcı Uri

http://hdl.handle.net/11527/19323

Gözat

Yazar "Orta, Deniz" ile LEE- Jeofizik Mühendisliği Lisansüstü Programı'a göz atma
  • Öge
    Numerical modeling of fluid and heat flow in southern North Sea: Investigating the role of faults and salt structures
    (Graduate School, 2025-01-09) Orta, Deniz ; Doğan, Doğa ; 505211412 ; Geophysical Engineering
    Determining how fluids and heat flow in the subsurface is crucial for exploring areas with geothermal potential. Thus, there are numerous geophysical, geological, and modeling research on this subject. The key objective of this thesis is to examine fluid and heat flow in the Southern North Sea along with their temporal variations and to understand the influence of the geological units, including faults and salt structures on this phenomenon. A numerical modeling approach was utilized for this objective to offer an understanding of the fluid dynamics and heat transfer within the region using ANSYS Fluent, a Computational Fluid Dynamics (CFD) software. The presence of faults and salt structures increases the contrast of various physical parameters in the region, suggesting that these structures will influence modeling outcomes, temperature distribution, and fluid flow. Thus, to characterize these structures and develop the two-dimensional real-earth model, extensive approaches were employed. The geometry of the main model has been established using offshore seismic reflection data from the Southern North Sea. After accurately creating the geometry, physical and hydraulic properties are assigned to the porous media serving as boundary and cell zone conditions. Parameters such as permeability, porosity, and thermal conductivity of the geological formations, as well as the temperature and pressure values at the model's boundaries, are included. Additionally, two test models (Test Model-1 and Test Model-2) were developed and computed in temporally and steady-state conditions, to analyze the behavior of the salt structures employing a consistent methodology. The test models are expected to establish a framework for the main model and will be compared with existing literature to validate the reliability of the modeling approach employed in this thesis. The results from both test models indicate that the presence of the salt structures has a great influence on fluid flow and temperature distribution throughout the region. The presence of salt, known for its high thermal conductivity, results in a significant thermal conductivity contrast with the adjacent geological units. As a result, models indicate higher temperatures reaching shallower depths, especially near the salt structure. An additional observation indicates that when the thermal conductivity of the salt increases, hot fluids reach shallower depths more quickly. Also, the program's reliability was shown by the outcomes of Test Model-2, which correlated with the current literature. The fluid flow and temperature distribution of the main model, along with their temporal variations, were subsequently obtained. The highest fluid flow velocity vectors were predominantly located in the fault since the faults have higher permeability. Thus, according to the results, faults act as conduits to help transmit the fluids in the subsurface. In addition, another key factor that affects the subsurface fluid and heat flow dynamics is salt structures. Due to the salt's high thermal conductivity, modeling results show that the fluids with higher temperatures move to shallower depths quickly, which is supported by test model results as well. Due to its low permeability and porosity, it allows a salt to function as a seal, which impacts the fluid dynamics in the region. In conclusion, it is demonstrated that faults and salt structures exhibit distinct differences from adjacent geological units in several physical parameters, including permeability and thermal conductivity. The model results indicate that underground systems influence the fluid and heat flow. Furthermore, computed numerical simulation results are expected to provide insights into the geothermal potential of the region and the fluid and heat flow dynamics.