glycol for geothermal drilling
Zandhoven-based Smeyers NV has become the leading market player for complex geothermal projects. The company’s drainage expertise has enabled it to develop the necessary know-how and experience. For geothermal drilling, Smeyers collaborates closely with Proviron’s Proviflow HTF Business Unit.
Commissioned by the ESCO Noven, the Flemish company completed one of the largest geothermal projects in Belgium. 180 drill holes, each 150 meters deep, have been completed at BULA in Bruges.
The main activity, drainage, is managed from the Smeyers headquarters in Zandhoven, where administration, planning, etc., are coordinated. A few years ago, geothermal energy was also started up. Based on a strategic vision, this activity began last year in Hoeselt following the opening of the new hub in Aalter. With three drilling towers, Smeyers Geothermie can handle more complex projects. “Preparation, organization and communication are very important. We work decentralized, the drilling rigs are deployed regionally. The drilling teams for East Flanders are managed from Aalter, and the teams for Antwerp and Limburg are managed from Hoeselt-Bilzen. These locally anchored drilling teams, including a site manager, project manager and supervisor, are well acquainted with the subsoil (sand, clay, Maas gravel, etc.). Our own service center in Beerse is on standby for any interventions on site,” says Tom Cox, Project Manager at Smeyers, 100% part of Aertssen Group since 2021.
drillmaster knows the surface
A company must be certified to perform geothermal drilling and work with drilling engineers certified by Embuild. At the drilling rig, an aspiring drill manager learns the practical aspects of the job from an experienced colleague.
Geothermal drilling impacts the subsurface because it penetrates multiple geological layers. After drilling, the boreholes are sealed to prevent the different geological layers from mixing. The flushing water reveals what is happening in the subsurface and helps anticipate any water loss,” says Cox.
"We're the only Belgian drilling company with a decanter centrifuge that purifies water on-site."
proviflow L as HTF for geothermal drilling
After geothermal drilling, the pipeline system must be filled with a heat transfer fluid. This is where Proviron, with locations in Hemiksem and Ostend, comes in as a specialist in glycol-based HTFs (heat transfer fluids). The company has a strong presence in the geothermal market under the brand name Proviflow, thanks to its high-quality inhibited glycol offerings. Proviflow is available in three variants: proviflow FG, proviflow Neo, and proviflow L (for geothermal applications). Glycol is naturally colorless and produced from the raw material MPG (monoethylene glycol) or MEG (ethylene glycol). In Belgium, only the non-toxic MPG variant is permitted for geothermal applications.”
Our added value lies in the right inhibitors that we add to the glycol. So you get a complete product that is corrosion resistant and makes optimal use of the advantages of glycol, such as efficient conduction of cold and heat,” says Brecht Polley, Proviflow Sales Manager at Proviron. “Our inhibitors are tested according to the American ASTM D-1384 standard. They are produced exclusively in Belgium and may be shipped abroad. The addition of glycol prevents algae formation in addition. The higher the glycol percentage in the mixture, the lower the freezing point – for example, -12.6°C at a concentration of 30%.
At this point, the glycol must still be safely introduced into the system. Therefore, a flow and pressure test is first used to check whether the heat pump system is completely airtight. If this is the case, a glycol leak is ruled out. Connecting the probes to the horizontal piping is done via a PE pipe and PE welding pieces. In large-scale BEO fields, testing is done zone by zone. Only if the system is completely leak-free is glycol ignited. Either the solution is purchased premixed, in the percentages requested by the client – usually 25% glycol,75% pure (tap) water. Or glycol is purchased in IBC drums and mixed in a mixing vessel on site. The amount of mixture required is determined as a function of the number of probes.
color additives in glycol
The inhibitors and the water’s hardness are especially important in determining the proper composition of the glycol mixture. Glycol is colorless. “The customer has the option of choosing the color and may have different reasons for this. “The customer has the option of choosing the color and may have different reasons.” For example, consider the potential confusion that could arise from storing red fuel oil and red-colored glycol in IBCs. Blue glycol is therefore often chosen as it makes leaks clearly visible. Finally, there’s also the marketing aspect. A customer with a yellow brand will often choose yellow,” says Brecht Polley.
investing in sustainable water use
Smeyers is bold to invest in sustainability. “We are the only drilling company in Belgium with our own decanter centrifuge that purifies drilling water from fine clay particles. The purified drilling water is reused during the drilling process or discharged. Smeyers goes for sustainable water use anyway. Customers appreciate this,” Cox says. “When drilling in porous subsoil, the use of drilling additives can limit water loss. After all, drilling is a water-intensive and invasive activity. There must always be sufficient buffer capacity of flushing water.” The BULA/Veemarkt site in Bruges is currently the largest geothermal project in our country. The intention is to provide this urban village in the making – with housing, SME units, studios… – with heating and passive cooling. Building owners in the healthcare sector also often call on Smeyers’ geothermal expertise.
For example, 46 boreholes are being drilled for the new hospital under construction in Lokeren. Complementary, small-scale residential projects – where a few glycol-based drillings are sufficient – belong to the company’s scope.
"proviflow is a complete product that is corrosion resistant and makes optimal use of the advantages of glycol, such as efficient conduction of cold and heat”
