| Title | Hydraulic & Thermodynamic Modelling of Multilateral Closed-Loop Geothermal Systems |
|---|---|
| Authors | Erin Gillis, Sara Eghbali, Colin Brown |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | In the Eavor-Loop™ design, multilateral well trajectories are designed to maximize heat transfer surface area between the circulating fluid and the surrounding rock. Mass flow rates in the laterals can vary and deviate from uniform distribution, influenced by factors such as lateral geometry and rock and fluid thermophysical properties. Production temperature, and thus thermal power output, is closely tied to this flow distribution. This study presents a coupled fluid-flow and heat transfer simulation of water circulation in an Eavor-Loop™ with user-defined multilateral geometries. Pressure differences at lateral junctions are evaluated, and an objective function based on the pressure error at these nodes is defined. A gradient-based optimization algorithm is employed to determine the mass flow rate distribution across laterals. The impacts of lateral trajectory design, simulation time, and flow distribution on thermal power forecast are analyzed. Simulation results indicate that uneven flow distribution leads to lower thermal power output compared to an idealized uniform distribution. However, reduced lateral flow rates experience more heat transfer and higher temperature due to the increased residence time of the working fluid, while increased lateral flow rates contribute to higher system flow rates and thermal duty. The overall impact of uneven flow distribution on the thermal output of an Eavor-Loop™ is minimal, illustrating the innate robustness of a closed-loop geothermal system. The impacts of Eavor-Loop™ design parameters, including lateral angle and spacing between lateral junctions, are also evaluated for their impact on flow rates in each lateral and the net effect on Eavor-Loop™ productivity. |