Bohrtiefe

Bohrtiefe is a term used in geology, mining, and drilling engineering to denote the maximum depth reached by a borehole from the ground surface. In German-language technical literature, it describes how deep a borehole extends and is often reported as the end depth of the hole. The concept is distinct from the depth to a particular horizon or target interval, which may be specified separately.

The term applies across multiple disciplines, including groundwater exploration, mineral and hydrocarbon prospecting, geothermal drilling, and geotechnical investigations. In groundwater projects, the Bohrtiefe helps determine the potential yield and the suitability of aquifers. In mineral exploration and geothermal work, it provides a measure for reservoir characterization and for planning subsequent logging, coring, or stimulation steps.

Measurement and documentation are standardized in borehole logs. The depth is measured from the ground surface downward to the bottom of the borehole, usually in meters. The actual depth can be influenced by borehole deviation, casing installations, and any backfilling or grouting. Detailed records include depth progression, casing depth, and intervals where the hole may be suspended or re-drilled.

Several factors influence feasible Bohrtiefe. Geological hardness, groundwater inflows, rock instability, and the performance limits of drilling equipment play major roles. Environmental and safety constraints may also cap the depth. Proper planning, well-designed casing and abandonment strategies, and adherence to regulatory requirements are essential to achieve the desired depth while maintaining well integrity and safety.

In practice, Bohrtiefe serves as a key parameter for resource estimation, hydrogeological assessment, and engineering design, informing decisions from sampling plans to long-term site management.