Directional Drilling

Geothermal Energy – a new approach to heat extraction

Geothermal energy is a renewable source of energy that is becoming more and more widely accepted. In particular, new developments in drilling technology and heat extracting methods provide an ever more efficient system approach.

The standard technology to harvest geothermal energy is based on vertically oriented boreholes. This is expensive, presupposes a well trained drilling team and very often causes damage to land and gardens. It is therefore not surprising that drilling costs regularly represent more than 50% of the entire investment.

The developers of the GRD method had these issues in mind. GRD is an innovative, slanted bore method where one central drill chamber is used to install borehole heat exchangers radially in all directions and angles of inclination, even under existing buildings. It is similar to the roots of a tree: all potential dimensions are used to provide a sustaining and efficient energy supply.

The compact Geodrill 4R is the only bore rig that is able to work in three dimensions.

There are several major benefits of the GRD method:

• Reduced investment cost of installation
  • The rig uses only a single location for drilling and manifold assembly
  • The GRD rig can be used in confined spaces and is quick to set up
• Greatly reduced damage to the immediate drilling area
  • All drilling is concentrated in a single chamber
  • The system is designed to manage all waste
• Improved heat extraction method
  • Utilises latest coax collector system
  • Able to fully exploit saturated geology where applicable

The innovative GRD system

The GRD system combines the advantages of ground heat collectors and borehole heat exchangers. The system utilises all the available land within the property boundaries.

The placement of the various boreholes, their rotation from a datum point and the angle are designed for maximum efficiency in heat collection.

Up to 480 metres of collector pipe may be connected to a single drilling/manifold chamber. If necessary, for higher heat extraction requirements, multiple chambers may be installed.

Using the chamber for drilling and as a container for the manifold greatly reduces the impact on the surrounding area during installation and provides an excellent environment for any maintenance.

What makes the GRD slant method unique?

• Optimum underground utilisation: the number and depth of borehole heat exchangers can be easily adjusted to the property's dimensions and local geology.
• The drill rig can be rotated horizontally 360 degrees. The angle of inclination is also adjustable, with a range between 35 and 65 degrees.
• Utilisation of the upper ground levels for efficient heat extraction.
• High and stable heat extraction.
• The borehole heat exchangers are combined in an accessible drill chamber – a clean and tidy solution.
• Efficient heat exchanger technology – ribbed coax collector.
• Short installation and cost recovery period.