Downhole Flow Management to Enhance Efficiency of Fractured Geothermal Systems in Horizontal Wells

Abstract

Real-world geothermal systems often suffer from low system efficiency due to thermal short-circuiting, in which case fluid only circulates through just few dominant fractures. This issue is amplified in horizontal wells with numerous natural or induced fractures. Our study proposes a novel temperature-sensitive flow management system to address this challenge and unlock the full potential of horizontal wells in Enhanced Geothermal Systems (EGS). This downhole system features real-time temperature sensors and flow control devices, dynamically adjusting injection across the wellbore to prevent thermal shortcuts. We evaluate the performance of such systems over 50 years of operation by numerical analysis. Numerical simulations over 50 years demonstrate its effectiveness: with the proposed flow control system, the produced fluid temperature remains 40 K higher compared to the EGS with the uncontrolled flow, leading to an extra 1.18 x 1016 J of heat extraction at the 50th year. This innovative flow management approach paves the way for transforming horizontal wells into efficient EGS systems for future power generation and heat extraction