# Special Issue: New Trends in Enhanced, Hybrid and Integrated Geothermal Systems
###### Abstract
As for the dynamic behaviour, the priority of the interior fins is also apparent. Generally, the research performed by [PERSON] et al. [6] confirms that the use of fins positively influences fluid temperature variations within the tube as well as the rate of heat transfer between the fluid and the borehole wall. The use of fins, especially interior fins, also enhances the thermal efficiency of a ground source heat pump system and reduces the length of the tube required and the initial expenses of the system. [PERSON] et al. [7] evaluated and reported on a location for a planned geothermal project, called the Alberta No. 1 project, which would produce power and heat (for direct use) at a commercial scale. The project is situated within the Municipal District of Greenview, south of the city of Grande Prairie, Alberta, Canada, and the evaluations demonstrate that there is a high likelihood of fluids up to 120 \({}^{\circ}\)C at depths of approximately 4000 m. According to the assessments conducted by the Alberta No. 1 project team, the target formations for this planned geothermal project consist of dolomitized carbonate units of the Devonian age from the Beaverhill Lake Group to the top of the Precambrian Basement. Additionally, Permeable Devonian-aged sandstone units such as the Granite Wash Formation are also targets. The authors' findings suggest that elevations at the top of the Beaverhill Lake Group range from 3104 m to 4094 m, and temperatures at the top of the formation range from 87 \({}^{\circ}\)C to 123 \({}^{\circ}\)C in the project area. Several potential challenges regarding the performance of sedimentary geothermal well-doublet systems, including heat conductivity, geochemical, and geomechanical conditions and issues, have been comprehensively examined and discussed by [PERSON] et al. [8]. These challenges may occur in the processes inside the reservoir itself, such as channelling, mineral precipitation and flow, and in the access and energy systems such as wells, heat exchangers, pumps, and surface tubing insulation. Some of their findings include that: (1) Chemical reactions can result in changes of flow-path, plus alterations of the rate of heat exchange between rock and water, and, consequently, changes in the reservoir's porosity-permeability and heat capacity; (2) Corrosion and scaling damage in the well-doublet systems diminish their performance and also influence their life-span; (3) Factors such as energy discharge rate and strategy, rate of injection, temperature and heat management, and well spacing contribute substantially to the heat recovery and life-span of a geothermal well-doublet system; (4) The injection of geothermal fluid such as water, carbon dioxide, and air into a well-doublet system can induce stress variations at a scale that will increase the likelihood of fault/fracture reactivation and induced seismicity. Therefore, realizing the magnitude of these events and their recurrence in time is important; (5) Factors including channeling, short-circuiting, leaking, heterogeneity, and permeability impairment can influence project viability, so they must be carefully evaluated during site assessment. Recognizing and understanding these challenges and issues will assist designers/engineers in better designing, implementing, and operating sedimentary geothermal well-doublet systems, leading to improved performance and increased efficiency of these types of systems, in addition to lessening their associated expenses and risks. [PERSON] et al. [9], by means of a hydro-thermal coupling model, numerically examined the impact of fluid flow direction on the heat transfer performance and specifications in a granite single fracture and validated the accuracy of the numerical modeling results experimentally. Their findings indicate a consistently robust relationship between the distribution of the local heat transfer coefficient and the fracture profile, independent of the axis.