Our geologists and geophysicists carry out borehole surveys using a wide range of intelligent tools. They can, if required, be used in various combinations.
We perform surveys in the areas of:
- Reserve exploration and mining
- Cavern construction
- Subsoil investigation
- Geothermal energy
Borehole surveys are used to determine geological and geotechnical parameters. This knowledge is often vital for later stages in planning. Based on the findings and the interpretation of the data, geological models of deposits can be generated and applications in soil and rock mechanics can be planned.
DMT borehole equipment can even be operated in offset and horizontal planes. In such cases the shuttle tool we developed is particularly suitable. It makes it possible to carry out closely targeted measurements underground and on the surface, all without laying cables.
Determination of Geotechnical Parameters
Geophysical borehole surveys supply important information about the stability and characteristics of the subsurface.
On the one hand, relevant geotechnical quantities can be determined. These include rock density, velocity of elastic waves, shear modulus and Poisson’s ratio (gamma-gamma density measurements and sonic logging measurements).
On the other hand, our surveys provide geological information about stratum interfaces, jointing and fault zones and their location. Visualisation is aided by imaging techniques such as sonic and optical scanning.
The data acquired from borehole surveys represent a wealth of information that can be used to determine the stability of load-bearing structures such as bridge foundations and abutments.
Hydrogeology and Well Exploration
When carrying out borehole surveys in new wells, a number of important aspects have to be clarified. For instance, the strata drilled through must be classified both lithologically and petrographically. Water-bearing veins and groundwater swell will have to be traced and jointed zones identified (using, for example, gamma measurements, electrical resistance surveys, gamma-gamma density measurements, porosity determination using neutron-neutron measurements and calliper logs).
Over and above that, our specialists determine water routes (cleavage zones), flow direction and flow speed. It is also useful to record the inflow and outflow profiles by means of fluid logging or flowmeter surveys.
In wells and groundwater monitoring boreholes we check the set-up (filter sections, clay seals and so on) and assess the permeability of filter sections. Well surveys can also be used to estimate water and gas saturation levels in the main body of waste dumps.