Faster, cleaner, deeper: the ORCHYD leap in geothermal drilling tech
It begins thousands of meters below our feet, where the earth’s ancient granite silently guards its secrets. For decades, engineers and scientists have known that beneath this formidable barrier lies an untapped reservoir of sustainable energy: geothermal heat. But reaching it has remained a colossal challenge.
In 2020, a coalition of researchers, engineers, and industrial partners from six organizations across Europe, the UK, and China set out on an ambitious mission. Their goal: to fundamentally change the way we drill into the earth’s hardest rocks. The result is the ORCHYD project, a fusion of cutting-edge hydro-jetting and percussive drilling designed to quadruple drilling speeds at depths beyond four kilometers. What’s at stake is not just technological prowess, but the potential to unlock a more affordable, reliable, and carbon-neutral source of energy for the world.
The challenge of deep drilling
The global push toward renewable energy is reshaping industries and policies. In this landscape, geothermal energy holds a unique promise: it is clean, sustainable, and – unlike wind or solar – available continuously, regardless of weather or daylight.
Yet, deep geothermal energy remains significantly underexploited. The primary obstacle is cost: over 50% of the total investment in a deep geothermal project is spent on drilling alone. The deeper we drill, the harder the rock, the slower the process, and the more expensive it becomes. When the drill hits crystalline formations like granite, rates of penetration (ROP) can slow to a crawl – sometimes as low as one to two meters per hour.
This image displays the borehole profile created in a sandstone sample using the ORCHYD drilling prototype. It clearly shows how the combination of percussion and high-pressure water jetting produces smooth borehole walls and effectively removes rock material. The visible peripheral grooves are a direct result of the simultaneous cutting and fracturing action enabled by the ORCHYD system.
The European Union’s Horizon 2020 research and innovation program recognized this bottleneck and funded ORCHYD, a project aiming to break through these barriers. ORCHYD fits squarely within the vision of Industry 4.0 and the green transition, combining advanced materials, intelligent simulations, and sustainability assessments to develop not just faster drilling, but smarter and more eco-conscious drilling systems. By making geothermal drilling faster and less expensive, ORCHYD could tip the balance in favor of geothermal plants in the global energy mix.
Anatomy of innovation: how ORCHYD works
At its core, the ORCHYD system merges two mature but previously uncombined technologies: High-Pressure Water Jetting (HPWJ) and percussive drilling.
This image illustrates the stress release principle at the core of the ORCHYD technology. The high-pressure water jet cuts grooves at the bottom of the borehole, relieving the surrounding rock from high stress concentrations. This process significantly lowers the energy required to break the rock, making it easier to drill at great depths in hard formations.
When conventional drilling meets hard, deep rock, the process is like trying to chip away at a fortress wall with a spoon. ORCHYD’s breakthrough comes from reducing the stress confinement around the drill bit. Using HPWJ, narrow grooves are cut into the rock directly ahead of the bit through a specially designed nozzle. These grooves release local stress in the granite, effectively making the rock “feel” shallower and easier to break.
Next-generation drilling with ORCHYD’s high-pressure intensifier and MudHammer
The percussion system, a high-frequency hammer known as the MudHammer, simultaneously delivers rapid, powerful impacts. Together, the jetting and hammering create a self-relieving process that enables the drill to bite through rock more efficiently.
This image shows the pressure intensifier specifically developed for the ORCHYD project. It is a key component that boosts the drilling fluid pressure to ultra-high levels, enabling the generation of a high-speed water jet capable of cutting through extremely hard rock at great depths. The new design, controlled by an electromagnetic valve, ensures a more stable and longer-lasting high-pressure jet compared to traditional intensifiers.
To power the water jet, ORCHYD engineers developed a novel intensifier that uses electromagnetic valves to regulate mud flow and piston movement. Unlike previous systems, this intensifier delivers sustained, ultra-high-pressure jets (up to 250 MPa) capable of cutting deep grooves into the rock. The MudHammer, supplied and modified by Drillstar, was adapted to handle the high-pressure mud flow without compromising its hammering action. Custom drill bits were designed with precisely placed nozzles and hammer inserts, optimizing both jetting efficiency and percussion.
Simulation-driven design
Behind the hardware is a mountain of computational research. Advanced Computational Fluid Dynamics (CFD) and Finite Element Modeling (FEM) helped simulate jet formation, pressure distribution, and rock fracturing at multiple scales – from the microscopic to the drill bit itself. The models were so detailed that they considered how individual granite grains would react to jet impacts.
This simulation-first approach allowed the ORCHYD team to optimize nozzle shapes, bit geometry, and even the chemical additives in the drilling mud – fine-tuning every element to maximize performance before setting foot in a lab or test rig.
The numbers are impressive: «In representative laboratory environments» says project manager Naveen Velmurugan from Mines Paris PSL, «ORCHYD technology achieved at least 4X improvement in ROP as compared to tricone roller bits.»
But the deeper impact is captured in the people and industries waiting for such breakthroughs. Imagine geothermal plant developers who currently face drilling budgets that can exceed 10 million euros per well. Reducing drilling time by even a third could turn marginal projects into profitable ventures, bringing geothermal heating to cities across Europe. Or consider the drilling teams themselves, who endure the physical and mental strain of operating complex rigs in harsh environments. A faster, more stable drilling system means fewer delays, fewer tool replacements, and safer operations.
Reducing CAPEX and risk in deep drilling
For geothermal operators, the ORCHYD system promises to dramatically cut capital expenditures (CAPEX) and reduce the risks that typically discourage investment in deep wells. By slashing drilling time and extending tool life, ORCHYD could make geothermal energy viable in locations previously considered too costly or challenging.
Though developed for geothermal, the technology has clear implications for oil and gas, particularly for deep wells in hard rock formations. Faster drilling can reduce both environmental footprint and operational costs – a compelling proposition as the industry faces increasing pressure to decarbonize. Deep hard-rock mining, where access tunnels can take years to drill, could benefit from ORCHYD’s stress-relief jetting to accelerate excavation, potentially making previously inaccessible ore deposits economically feasible. Major tunneling projects through granite or basalt – think high-speed rail tunnels or underground infrastructure – could adopt hybrid percussion-jetting technologies to reduce boring time and improve precision.
The human equation
Drilling, especially at great depths, is a dangerous and demanding profession. Slow progress not only racks up costs but exposes crews to extended periods of operational risk. Faster drilling reduces time on site, lowers accident potential, and minimizes workers’ exposure to challenging conditions.
Additionally, ORCHYD’s environmentally conscious design, which includes the use of graphene oxide modified with hybrid nanosilica as a drilling fluid additive, highlights a broader shift in industry attitudes: it’s no longer enough to simply drill faster – we must drill cleaner and smarter.
Public perception also plays a role. The ORCHYD project conducted social acceptance studies, revealing that communities are more likely to support geothermal projects when they are perceived as safe, efficient, and environmentally friendly.
From lab success to real-world deployment
No innovation is without challenges. Moving from controlled lab tests to real-world geothermal fields will present hurdles: variations in rock formations, unpredictable downhole conditions, and integration with existing drilling platforms. Moreover, while the electromagnetic valve-based intensifier performed well in trials, ensuring its reliability under sustained, real-world stress will require further testing. Scaling up also means managing the complex logistics of adapting drill rigs and training personnel to operate these advanced systems.
Finally, regulatory pathways must be navigated. Introducing new downhole tools into geothermal operations requires certification and acceptance by safety authorities – a process that can be time-consuming but is essential for widespread adoption.
The ORCHYD project’s success in laboratory and prototype demonstrations lays the foundation for the next critical step: field trials in operational geothermal sites. These trials will test the technology under the full spectrum of geological and mechanical stresses. If the system performs as anticipated, it could catalyze a shift in geothermal drilling economics, making geothermal energy more competitive with other renewables.
By the end of 2024, the project concluded with a successful demonstration of the full prototype, combining high-pressure water jetting and percussion.
Opening image: ORCHYD team in front of the drilling test bench just after the final demonstration
