geologieThe geology of the area under Westland and suitability for heat production is studied by geologists and geophysicists. The well proposal was made by PanTerra​​. In this well proposal you can find the well trajectory with well depths and direction, which layers will be tapped and the depth at which these layers are located. By means of this well proposal the technical well design has been made.

The layers used by Greenwell Westland are the Delft and Pijnacker Sandstone layers. Two wells drilled each with a length of 3200 meters. Because the wells diagonally away is the deepest point of the well 2,800 meters below the surface. The ends of the pit in the substrate are approximately 1500 m apart. The Delft sandstone is at a depth of 2400 m, and it has a temperature of about 85 degrees. Warm water is pumped up from one well too the heat exchanger on the surface, the heat is extraced and the cooled water is pumpeddow throught the other well.

Continuous during drilling geologist investigate and report what the composition of the layer is that currently is being drilled. This is to map the geological layers in Netherlands.