Borehole logging
Methods and services
Borehole logging, also known as well logging is the detailed analysis and capturing of the local ground conditions in a borehole. Geophysical borehole logging aims to provide accurate data of the physical properties of geologic structures and the groundwater within the borehole. Borehole logging is a time and money-saving approach that can gather rich data that is otherwise only obtainable by core-sampling methods.
Shortly on the method
The borehole logging measurements are mostly used to maximize the information gathered from geotechnical drillings. Information is being gathered through visual inspection of samples brought to the surface or from geophysical surveys performed along the axis of a borehole. The measurements are carried out with several special logging devices which are lowered into the borehole. This device is moved up and down in the borehole while recording the data. The logging tools range from mechanical devices, nuclear/gamma, acoustical, electrical, imaging, and sensors for fluid properties.
Services
Optical Televiewer
A 360° optical images of the borehole wall. Provides information of fractures and other geological features.
Electrical Resistivity
Characterizing the rock or sediment in a borehole by measuring its electrical resistivity. We can gain information about permeability, porosity, water quality and geological formation properties.
Spectral Gamma
Measures the total gamma counts in API as well as the full energy spectrum of the gamma radiation emitted naturally from within the formations
Acoustic Televiewer
The sensor sends out ultrasound pulses which trough an image of the borehole wall can be made.
Induced Polarization
Measures the electrical resistivity, spontaneous potential and chargeability of rocks. A high chargeability response is an indication of the presence of metallic sulphides and oxides or cation-rich clays.
Natural Gamma
Measures the amount of gamma radiation occurring naturally within the formations crossed by a borehole
Flawmeter
Identifies, measures and quantifies the flow of groundwater in a borehole. To detect these low flow rates, measurements must be made while the probe is stationary at different depths
Water Quality
It uses reliable, accurate and drift-free high quality sensors and records a continuous profile of the borehole fluid properties.
Magnetic Suspectibility
It is compatible for measurements in complex igneous or metamorphic rocks up to high magnetite rocks.
Temperature and electrical conductivity
The probe provides information of the temperature and electrical conductivity of the borehole fluid.
Borehole Diameter
Probe provides information of the borehole diameter at various depths
Full Waveform Sonic
Sonic logs are widely employed, often in combination with other logs, to provide porosity, permeability, and geo-mechanical properties.