Specialists in Soil Investigation
The Trias
drilling for geothermal project Trias
Westland in Naaldwijk, The Netherlands, started a month ago. The drilling of the first
section went well. In the first days it
proved to be a challenge to control the drill
head in the limestone formation. It was difficult to maintain an angle of 30
degrees in the soft rock containing hard flintstone. For this reason the
drilling of this secton took more time than anticipated. The first section is
about 1,300 meters deep. In the weekend of 18/19 November, the steel tube
(casing) with a diameter of approximately 50 cm was inserted into the borehole.
The space between the borehole and the outer wall of the casing was cemented to
reinforce the borehole.
Blow Out Preventer
After cementing the first section, the Blow Out Preventer (BOP) was installed
and tested. The BOP checks the pressure in the drill shaft and mechanically
closes the hole in case of sudden pressure waves (blow-outs). The BOP is of
great importance for the safety of the crew, the drilling installation and the
environment. The first pressure tests at Trias Westland showed that the BOP did
not function well enough. A part of it has been repaired in Germany. Two days
later the BOP could be installed and adjusted. The system is now functioning
properly.
Heading for 2,550
meters
The drilling of the second section started November 29. The borehole in this
section has a diameter of approximately 45 cm. The drilling runs smoothly with
an average speed between 10 and 15 meters per hour. We expect to be finished
with the drilling of this section in a few days time, having reached a depth of
2,550 meters. A casing will then be
inserted and reinforced with cement. Take a look at the video to learn more
(Dutch only).
T&A Survey
has been involved in the Trias Westland project from the very beginning and now
provides the drilling management. Read more about the project.
