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  • GTD Drilling


Those involved in ground source heat pump (GSHP) drilling operations will no doubt have heard of GTD’s drill rigs and equipment. Its seemingly rapid rise to success, initially in the UK and now internationally, prompted GDI to delve deeper into how it has accomplished this feat and solidified its position as a global player in the GSHP sector.

Global governments are rapidly coming to the realisation that GSHP is one of the greenest, cleanest forms of heating and cooling, and crucially it also relieves pressures on growing electrification demands. Equally, attitudes and expectations are shifting away from quick fixes and rapid returns to an increased emphasis on the need for longer-term solutions with greater returns over time. Air source heat pumps have their place and are part of the remedy, but ground source heat pumps are without question a more efficient and effective long-term solution. Governments, trade organisations, regulators, planners, in fact, everyone who has a professional role or responsibility in delivering green energy, utilities or systems, knows that they must find a way to scale the adoption and integration of GSHP installations, be they individual or large-scale shared utilities. This is welcome news for drillers as the opportunity to expand or diversify into shallow geothermal drilling has become a viable business proposition. If you are not considering geothermal drilling, you could now be overlooking one of the most significant opportunities in our drilling lifetime. The incentives for geothermal drilling are expected to continue and grow for at least the next 10 to 12 years.

Specialist equipment

GTD has rapidly established itself as a key manufacturer of specialist shallow geothermal drilling equipment and for good reason. Its drill rigs have been trailblazing new standards for productivity, safety and simplicity for drillers. GTD has also addressed affordability and availability, with fully specified rigs at a price point that is considerably lower than expected, and with delivery lead times of just five to six months (depending on shipping locations). It is clearly apparent more and more GTD rigs are being utilised across the globe - GTD is now the fastest-growing global provider of specialist shallow geothermal drill rigs.


We established a family-own business dedicated exclusively to drilling shallow geothermal boreholes


It is not often that a new manufacturer enters the drilling market and grabs the industry's attention as much as GTD has over the past two years. So, what is the story behind GTD, and how has a relative newcomer to the industry been able to make such an immediate impact?

Speaking at the company's headquarters in Kent, UK, Alex Bosch, a partner at GTD, said: "More than two decades ago, we established a family-owned business dedicated exclusively to drilling shallow geothermal boreholes. In the initial years, the industry was financially unforgiving, with the widespread belief that the cost of borehole drilling was excessively high and, therefore, unviable. For context, in the UK, we can experience unpredictable and changeable geology on drill sites just a few miles from each other. In fact, it's not uncommon to find different geological conditions on an individual drill site, which highlights the complexity of the problem and the equipment necessary to overcome these challenges.

Specialised drill rigs for shallow geothermal drilling were unobtainable, and we had a hard time finding a rig capable of delivering the productivity we knew was feasible.

"During our initial drilling efforts, we discovered numerous limitations in the equipment available. We were unable to find a rig that provided the versatility we needed to allow us to adjust our drilling methods according to the UK's complex and diverse geological conditions. Most rigs available at the time were tailored to specific subsurface geologies and restricted drilling techniques; this was not a solution for us, as we needed the flexibility to adapt a single rig to all drilling conditions and geologies."

Industry collaboration

Identifying and addressing these shortcomings, GTD took the initiative and collaborated with a manufacturer to develop a specialist geothermal rig meeting its specifications and design requirements. The rigs were very much born out of necessity, giving the family drilling business a substantial competitive edge, winning drilling contracts and ultimately completing them to depth, within schedule and budget.

"Over the past two decades, we have continually developed the rigs, the features and components," Bosch said. "It has been refined and optimised for user-friendly operation, lessening the burden on both the machinery and the operators, while increasing efficiency and making it easier to tackle bigger projects and deeper boreholes, in line with market expectations. Meanwhile, we have watched from a distance as other contractors utilised far more expensive rigs, with more intricate systems and complex electronics, yet are still unable to match the consistent productivity that our rigs have been attaining."

The family's rig eventually turned into what is now GTD's bestselling model, the GT35. Together with its manufacturing partners in South Korea, GTD took the decision to produce the rigs for the growing market. Initially launching in the UK, then rapidly expanding internationally.

Ease of operation

Simon Sergides, head of operations at GTD, explained how the rig has driven the company's remarkable growth: "Our rigs are known for their ease of operation, safety, and efficiency - all crucial attributes when addressing the equipment and workforce gaps that the industry urgently needs to close. The rigs are straightforward to operate, maintain, and repair - all vital factors for any drilling business, as downtime is the nemesis of productivity. We took a more pragmatic and practical approach to the rig's engineering and components, focusing on simplification and streamlining to make the rigs easier to operate and service in the field.

"Regardless of how robust and reliable your machinery is, drillers and geology can cause damage. Often, efficiency lies in how quickly something can be fixed, as drilling is about keeping your rods turning in harsh and unpredictable environments. The GTD rigs use straightforward hydraulics, so procuring repair parts is hassle-free, with numerous local suppliers available. There are no complex or proprietary electronic components that can cause additional repair delays and disrupt project delivery schedules.

"For us, simplification was a priority, as we've demonstrated that being able to make temporary fixes for unforeseen issues, sometimes by simply redirecting or reusing another hydraulic hose, allows a hole to be completed while replacement parts are being delivered to the site for a full repair.


We also test, prove and adopt components in specific territories


"We listened to our drilling peers and the financiers behind them, ensuring our commitment to easy repairs, through universally available and non-proprietary parts, which is as important to them as it is to us. We utilise efficient Doosan engines, which have extensive global servicing and spares availability. We also test, prove and adopt components in specific territories. In Europe, dual centrifugal Caprari mud pumps are widely deployed on our rigs as they offer adaptability and redundancy. In the US, single or dual 4x3x13 centrifugal pumps, like the 250 Mud Puppy, have been integrated and dialled with great success. We are very flexible and always open to new learnings and approaches, but we instinctively return to core the question: ‘Will this increase productivity?'"

Safety enhances efficiency

It is rare for safety and increased productivity to be directly connected, as introducing safety features can often create processes that hinder efficiency. However, it is refreshing to discover that GTD has successfully implemented solutions that promote safer work practices while simultaneously increasing profitability through more effective drilling.

With the Safety Cage Removed, the GT25's Rod Handling System can be Clearly Seen

Sergides elaborated: "Safety has been engineered into all our equipment. One of the most talked-about and arguably most defining features of the rig is its rod rack and loading system. The GT35 has 6m (20f) long rods onboard and a storage capacity of 240m (800ft) in the rack, which it handles effortlessly and hands-free. Operated by the lead driller, second operator, or both using dual controls, the system considerably reduces operator fatigue and the risk of injuries associated with repetitive manual handling of rods. Remarkably, this automation occurs within the compact footprint of the rig and its surrounding safety cage, enabling access to restrictive borehole locations that other rigs cannot reach.

"The safe use of longer 6m rods also offers numerous other benefits. For instance, if 2m (6.6ft) rods were used, there would be three times the mechanical movements throughout the day, leading to increased operational wear, fatigue and associated risks. Shorter rods require more frequent driller interaction, while longer rods save valuable time, allowing the drilling crew to focus on other tasks."

Seeing is believing

There is no better way to fully appreciate the effectiveness of GTD's rigs and equipment than see it in action drilling. GTD welcome live drill site visits, where potential users can get up close and personal. The team is particularly candid when it comes to sharing its methodologies, techniques and setups, and genuinely cares about increasing both customers and industry productivity. The first port of call, and the next best option to a site visit, would be to watch some of the videos GTD has shared online:

No hole - no box

Without boreholes, the demand for the associated heat pumps is entirely constrained. Undoubtedly, the most significant challenge the industry faces is meeting the demand for drill rigs and drillers. As more governments and organisations persistently introduce new incentives and enforce regulations promoting the use of GHSP systems, gaining access to equipment and drilling training has become a vital priority that is being addressed with a growing sense of urgency.

Currently, GTD is collaborating with GSHP associations, regulators, industry leaders, and influential voices in the geothermal heat pump industry on both sides of the Atlantic, playing a significant role in training and workforce development strategies. The company understand that its contribution extends beyond merely keeping up with the demand for a supply chain of capable, safe, reliable, and efficient rigs; it also involves its collaborative role in building the necessary industry skillsets for current and future generations.

Alongside the equipment manufacturing, GTD's pre-existing family drilling business continues to thrive, and it remains at the forefront of the GSHP contract drilling industry, with operations expanding to capitalise on the growing demand for boreholes. Naturally, it uses the latest evolution of its pioneering drill rigs and equipment, which it continues to develop. The difference now is that the family's equipment and drilling techniques are no longer guarded as "trade secrets". Instead, it has adopted an open approach, willingly demonstrating techniques and processes. It recognises the need for an abundance mindset and is driving the entire industry to deliver on its potential.

GTD has undoubtedly caught the eye of the industry, seemingly providing the appropriate equipment, delivering true value and just when it is needed. With such a strong focus on clean energy, the sector can expect to continue seeing a growing number of GT Series rigs and equipment drilling down to net zero in countries around the world.

Productivity, capability & performance

  • The GT35 delivered the UK's deepest closed loop geothermal borehole when a 1,350ft (412m) bore was drilled right next to the tallest building in Central London.

  • At a jobsite in Holland, 13,500ft of drilling was achieved along with loops installed and grouted in a week using a GT35 rig.

  • As part of a 700 borehole project at the Netflix studio development in New Mexico, US, a GT35 rig was boring six holes a day.

An Aerial Shot of the GTD GT35 Rig at Work on the Netflix Studio Development

The GT35 rig features

Rather than listing all the specifications take a look at this video which demonstrates all of the GT35 rig features in operation.

This video demonstrates how a GT35 rig enables the lead driller to oversee and execute the entire drilling process with minimal support. The driller is setting the hole, handling all the rods hands-free, running the mud system, and prepping the loop himself, while his second operator is grouting and finishing the install of the previously drilled borehole. It is impressive to witness in real time.

In this time-lapse video, you can truly appreciate the advantages of the GT35's features and rod handling system, as it demonstrates a typical day of drilling on a 700 borehole project in Albuquerque, New Mexico.

A two-person team drill six holes, install loops, grout, and then set up for the seventh hole, all within a single day, even while dealing with diverse weather conditions, including snow. The lead driller handles all the downward drilling processes, while the second operator joins the controls every time they are pulling out to increase the speed. The tracked equipment is extremely fast to move in just a matter of minutes to the next array hole location.

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