Borehole Logging

DMT has a broad portfolio of borehole logging tools for a wide range of applications, from small water wells to geothermal wells several kilometers deep.

All common measurement methods to determine formation properties for open boreholes, as well as for casing inspection in cased boreholes, are available for:

• Goethermal energy
• Reservoir exploration 
• Geotechnical investigations
• Hydrogeology
• Mining and tunneling
• Abandoned mining, shaft surveying and mine water drainage
• Borehole integrity
• Exploration of nuclear waste repository locations

Accurate knowledge of reservoirs is essential for the effective exploitation of geothermal energy and the production of hydrocarbons from deep wells. Much of the information used to determine characteristics is obtained through borehole logging. Lithology, fault zones and fault types, as well as temperature and porosity are just some of the parameters that can be determined by borehole geophysics to optimize the exploitation of the full potential of a reservoir.

Geophysical borehole logging provides important information on the structure, stability and nature of the subsurface. Geotechnically relevant rock properties are determined, such as: rock density, velocity of elastic waves, shear modulus and Poisson's ratio, electrical properties, as well as stratification, fractures and fault zones.

Based on the borehole geophysical measurement results, the subsurface can then be classified lithologically and geotechnically. This allows future construction projects to be planned more precisely and the associated construction risks to be better assessed.

Well logging can be used in hydrogeological wellbores to improve the understanding of the hydrological situation. Properties such as porosity, flow rate, permeability and kf-value (nat. gamma, density, tracer fluid logging, flowmeter, salinity and temperature) of ground water resources can be explored. In addition, milieu logs and sampling are used to inspect groundwater quality and potential contamination or mineralization.

DMT has special methods that can also be carried out in horizontal and upward boreholes, e.g. using borehole and cavity scanners, borehole cameras, 3D-borehole radar and borehole tomography. Geological structures in the subsurface such as strata boundaries, cavities, zones of weakness, karst cavities or non-consolidated zones in the vicinity of the tunnel are explored; often in advance of TBM excavations and during refurbishment or extension of existing tunnels.

Inspection of the casing, cementation, filter sections, joints and backfill are carried out directly after the boreholes have been drilled. Repeated borehole measurements allow early detection and remediation of possible defects in casing (corrosion damage), filter sections (clogging), sleeves (leaks) and backfill (washout, erosion or clogging).