New closed loop horizontal geothermal well solution using a continuous vacuumized pipe for direct district energy and heat storage usage

Presentation Description: To efficiently harvest deep geothermal energy universally an innovative closed loop horizontal well solution is proposed, which can be implemented in any geological setting as there is no requirement for fluids to circulate through a geological formation. This is unlike the doublet hydrothermal solution, which has specific geological requirements. The geothermal well is drilled to a depth of 3-5 km depth with an up 5 km horizontal section utilizing oil field drilling technology and completed with a pipe-in-pipe concept with the inner pipe having a double wall with a continuous vacuum. The fluid will flow within the outer pipe spacing and along a geological formation in the horizontal section of the well. In this process, the fluid is heated and then returned to the surface in the inner dual vacuum pipe at the toe of the well with minimal heat loss by being similarly to a thermoflask. Without continuous vacuum 30-40% of the energy harvested is lost on the journey to the surface. There is no downhole maintenance of equipment and the maintenance of the surface equipment is minimal as the circulation fluid is not exposed to damaging formation fluids. A reliable and constant production of a heated fluid at a temperature not requiring electricity to lift the temperature is possible. The deep geothermal solution can be designed to last 50-100 years with virtually no CO2 emissions. The solution can be connected to district energy systems, have a range of industrial applications and can be used for heat storage.

Case Study: The closed loop horizontal geothermal well solution has been implemented in a test well in Stavanger, Norway in 2024, where it was proven that the well completion works, that the continuous vacuum can be maintained and has a unique insulation effect of the heated fluid returning to surface.

Keywords: Geothermal, Closed Loop, Vacuum, Heat