TY - THES

T1 - Economic-Technical Evaluation of Insulated Tubings for Completions in Geothermal Energy Applications

AU - Mark, Daniel

N1 - embargoed until 17-10-2028

PY - 2024

Y1 - 2024

N2 - Energy that is obtained from geothermal sources is considered as renewable energy and therefore one of the technologies that will enable us in the future to largely or, in the best case, completely replace climate-damaging fossil energy sources, which are oil, natural gas and coal. Since geothermal energy competes with other renewable energy sources, it is necessary to achieve a technical and economic optimum for the system components. The master's thesis deals with the question of whether the use of insulated pipes in the borehole offers economic added value compared to the generally used, uninsulated standard pipes, which are also used in the oil and gas industry. For this purpose, different insulation solutions are considered regarding heat transfer behavior and friction losses. The master's thesis is divided into a theoretical and a practical part. In the first section of the theoretical part, geothermal energy is described in a technical manner, and the basics of heat transfer are discussed. The particular focus here is on the description of the technologies currently most used to generate geothermal energy and the derivation of losses through heat transfer mechanisms and pipe friction. The second section of the theoretical part takes a look at the market for alternative energy sources, in particular geothermal energy. Economic indicators are also mentioned that can be linked to the potential increase in efficiency resulting from the insulation of pipes. In the first section of practical part, different insulation solutions are examined technically and economically in two different theoretical models. The former model is an application in which the production probe is separated from the injection probe. The other model represents a "single borehole" solution in which the injection probe and production probe are the same. Some fictitious but realistic values were used as input values, which is due to the aim of achieving results that are as general as possible. It turns out that certain insulations can deliver significant added value in terms of technical performance and economic outputs, despite considerable additional costs. The second section of the practical part deals with the question of whether pipes made of steel have added value compared to those made of plastic in near-surface geothermal energy applications. An evaluation scheme was used for this purpose, which in the end clearly negated the question.

AB - Energy that is obtained from geothermal sources is considered as renewable energy and therefore one of the technologies that will enable us in the future to largely or, in the best case, completely replace climate-damaging fossil energy sources, which are oil, natural gas and coal. Since geothermal energy competes with other renewable energy sources, it is necessary to achieve a technical and economic optimum for the system components. The master's thesis deals with the question of whether the use of insulated pipes in the borehole offers economic added value compared to the generally used, uninsulated standard pipes, which are also used in the oil and gas industry. For this purpose, different insulation solutions are considered regarding heat transfer behavior and friction losses. The master's thesis is divided into a theoretical and a practical part. In the first section of the theoretical part, geothermal energy is described in a technical manner, and the basics of heat transfer are discussed. The particular focus here is on the description of the technologies currently most used to generate geothermal energy and the derivation of losses through heat transfer mechanisms and pipe friction. The second section of the theoretical part takes a look at the market for alternative energy sources, in particular geothermal energy. Economic indicators are also mentioned that can be linked to the potential increase in efficiency resulting from the insulation of pipes. In the first section of practical part, different insulation solutions are examined technically and economically in two different theoretical models. The former model is an application in which the production probe is separated from the injection probe. The other model represents a "single borehole" solution in which the injection probe and production probe are the same. Some fictitious but realistic values were used as input values, which is due to the aim of achieving results that are as general as possible. It turns out that certain insulations can deliver significant added value in terms of technical performance and economic outputs, despite considerable additional costs. The second section of the practical part deals with the question of whether pipes made of steel have added value compared to those made of plastic in near-surface geothermal energy applications. An evaluation scheme was used for this purpose, which in the end clearly negated the question.

KW - Geothermal energy

KW - optimization

KW - heat loss

KW - insulation

KW - tubings

KW - economic consideration

KW - Geothermie

KW - Optimierung

KW - Wärmeverlust

KW - Isolation

KW - Rohre

KW - Wirtschaftlichkeitsbetrachtung

M3 - Master's Thesis

ER -