The delivery and construction of the drilling tower for the Trias Westland geothermal project has been completed. The parts of the KCA Deutag drilling tower arrived at the construction site on Lange Broekweg in Naaldwijk in containers brought here over the course of the past few weeks on exceptional transports. The first hole will be drilled on Monday, 6 November.

The KCA Deutag rig is a complex piece of equipment, measuring approximately 52 metres in height and capable of lifting an auger rod weighing approximately 350 tons. With a capacity of 1500 HP, the rig can reach a depth of up to 5,000 metres.

Drilling tower

Last week, the 43-metre-high mast of the drilling tower arrived at Lange Broekweg in Naaldwijk, thus enabling the tower to reach its highest point yet, at 52 metres above ground. The drilling tower, supplied by the KCA Deutag drilling and engineering firm, had been used in the gas and oil industry before and was shipped from Turkey to the Netherlands.

Start of the drilling

On Friday, 3 November the chisel will be ‘blessed’, and on Monday, 6 November the first hole will be drilled. The conductors, 125 metres in depth, were installed last June. The first well test is expected to take place in January 2018. Director Marco van Soerland: ‘Six years after signing the letter of intent, we can finally start drilling. This is a special day for all the growers involved, HVC, Capturam, Royal FloraHolland, the municipality and the project team. Of course, we are all looking forward to the well test in January. No matter what the outcome: through this project we are making giant strides in energy transition in the province of Zuid-Holland, due to the knowledge we are acquiring about heat in the deep layers of the earth and by launching such an exceptional geothermal project.’

In four sections to a depth of 4,560 metres

On Monday, the first hole will be drilled, also referred to as ‘spud’ in the oil and gas industry. This is a 125-metre hole located precisely where the protective layer for the water-bearing layers was installed last June. After this relatively shallow hole has been drilled, the first section of the deep drill will follow. During the next 7 to 9 days to come, a hole 1,298 metres deep and with a diameter of approximately 60 centimetres will be drilled. During this process it is essential that the drill grit is brought to the surface. A sample will be taken every 10 m of the mud and grit that is extracted by the drill, as this will inform the drilling crew of which layer of the earth and at what depth the drill bit is situated. Once the full depth of Section 1 has been reached, the pipe is inserted and cement is pressed between the borehole and the pipe to reinforce the hole. Section 1 will be completed after approximately 2 weeks. The next step is Section 2, with a diameter of about 43 centimetres and a depth of up to 2,559 metres. Section 3 is a borehole with a diameter of about 30 centimetres and that will go down as far as 4,204 metres. Section 4 drills through to the Trias layer, at a depth of 4,560 metres. This last hole is not cemented in connection with the heat that will be extracted.

Trias Westland

The Trias Westland test well is a unique geothermal project. Never before has drilling taken place to a depth of 4 km with a view to extracting geothermal heat in the Netherlands. Trias Westland B.V was founded by Royal FloraHolland, HVC and Capturam to investigate the extraction of geothermal heat for economic purposes at this depth. The goal is to find out if extracting geothermal heat is economically viable at a depth of 4 km, with a view to making this heat available to greenhouse horticulture companies in the Westland region.

Source: Trias Westland. Photos: Mario Bentvelsen.