Bohrloch

Bohrloch is the German term for a borehole, a narrow hole drilled into the ground to access subsurface formations, collect samples, or monitor conditions. It is used in geology, hydrogeology, mining, engineering, and energy exploration to reach aquifers, mineral deposits, or rock units and to enable data collection or fluid movement to the surface.

Construction and design are driven by the borehole’s purpose. Drilling uses a drill rig and drill string with a cutting bit, often aided by drilling fluids that stabilise the hole and carry cuttings away. Depending on use, casings or liners may be inserted to prevent collapse and to isolate groundwater zones or rock layers. Hole diameters vary from a few centimetres to several decimetres, and depths range from tens of metres to several kilometres. Boreholes may be vertical, inclined, or horizontal, and they can incorporate sensors, pumps, or perforated screens.

Applications are broad. They include groundwater monitoring wells, water supply or geothermal probes, mineral and hydrocarbon exploration, environmental sampling, and geotechnical testing. Data are gathered through core sampling, borehole logging, and downhole instrumentation that record properties such as rock type, porosity, permeability, temperature, and fluid pressures.

Decommissioning and safety are important aspects. After use, boreholes are sealed or grouted to prevent contamination and collapse, following regulatory requirements. Proper abandonment, maintenance, and documentation help minimize environmental impact and ensure long-term stability of the subsurface record.