Emerging Drilling Technologies Unlocking Deep and Medium-Deep Geothermal Energy

Medium-deep and deep geothermal resources are pivotal for future low-carbon energy, contributing to both heat supply and dispatchable electricity. Conventional drilling methods, especially for Enhanced Geothermal Systems (EGS) and Advanced Geothermal Systems (AGS), face high costs—up to 70% of total project expenditure—due to technical limitations and reservoir uncertainties. Recent advancements include alternative rock-breaking mechanisms such as steel shot drilling, laser drilling, pulsed plasma, and high-power microwaves, all designed to enhance the rate of penetration (ROP), bit longevity, advanced directional control, and operational efficiency. Hybrid systems combining these techniques with established polycrystalline diamond cutter (PDC) bits are emerging, leveraging strengths from multiple technologies. Furthermore, automation and robotics—drawing on developments from the oil and gas sector, including AI and machine learning—are revolutionising routine and complex drilling operations, increasing safety and performance. Supported by the IEA Geothermal Technology Collaboration Programme emerging drilling technology have been comprehensively reviewed, presenting high-TRL innovations and automation solutions. These developments collectively aim to reduce upfront investment risks, improve reservoir access, and support the economic viability of geothermal projects, thereby facilitating the global transition to renewable energy.