Vacuumized Pipe-in-Pipe Solution for Efficient Geothermal Heat Extraction Everywhere for District Cooling and Heating

A new horizontal geothermal well solution is using a completely closed loop system for the circulation of a fluid in a vacuumized pipe-in-pipe (co-axial) system. The fluid is heated by the geological formation in the horizontal section of the well and returned to the surface with a very limited heat loss. With the closed loop solution there is no requirement for a geothermal reservoir with a certain porosity, permeability and flow characteristics and therefore the solution is independent of the geological setting and has a near universal application. This reduces most of the risks associated with conventional doublet hydrothermal well solutions, that often fails due to an impermeable heat reservoir. For a successful execution, proven oilfield drilling technology and services are utilized. The drilled depth determines the temperature of the returning circulation fluid. The thermal conductivity of the geological formation of the horizontal well completion and the fluid flow rate controls the thermal energy output (MW). The solution is suitable for initial subsurface temperatures around 150°C or lower. The formation temperature around the well will decrease over time due to the energy production. The temperature range makes the solution suitable for producing thermal energy for district cooling, directly for district heating and for various industrial usages.