Deep Hole Hammers for Geothermal
Services (Technical Disciplines)
Development of Deep Hole Hammers (DHHs) for the Swedish ‘Drilling for Energy’ industry.
Three Nemek 407 drilling rigs were used all equipped with Mincon 5” DHHs, on the Karlstad geothermal energy project.
This project involved the formation of a non-uniform grid of 101 x 140mm diameter boreholes to a total depth of 120 metres in Swedish Granite.
The first 3m of each borehole was cased using 168.3mm (6 5/8”) casing to secure the borehole against ‘top-breakage’.
Penetration rates using the Mincon 5” Deep-Hole hammer were in excess of 30m per hour throughout the contract and the hammer design ensured that the progress made at full depth and under a considerable head of water remained impressive.
The drilling element of the contract was completed on time as was the installation and commissioning. Water was present in boreholes at between 30m and 48m depth which required extra care to be taken to avoid borehole deviation.
The geothermal energy system is now producing 85% of the requirement for heating in the development and 75% of the required cooling levels, the remainder being provided by water and wind generation..
Mincon worked with a leading Swedish contractor, Finspångs Brunnsborrning, in manufacturing DHHs to complete heat pump installation works; drilling capability averages 35 holes per week to varying depths and formations.
Geoscience Ireland Contact
Gerry O’Connor <firstname.lastname@example.org>