Borehole Logging

Optical Borehole Scanning Service

Capabilities of the optical scanner include

  • Continuous, detailed, and scaled 360° true-colour images of the borehole walls for documentation and interpretation (standard file formats, bmp, tiff, etc.)
  • Feature analysis including dip, strike, frequency, and fracture aperture
  • A popular visual data display option is the projection of features onto an imaginary core that can be rotated and viewed
  • Replacement of expensive coring with its associated problems of incomplete core recovery
  • Borehole deviation log (dip and dip direction of the borehole) to calculate the true borehole coordinates x, y, z for the production of bulls-eye diagrams, etc.
  • Total magnetic field strength and magnetic field vector information
  • Natural gamma ray information
  • 150 m scan within 1 hour with a vertical resolution of 1 mm
  • Surface and underground, vertical and horizontal, core and RC drill holes
  • Portable and vehicle-mounted operation

Borehole Scanning Processing and Interpretation Services

The image shows the circumference of the borehole developed on a plane.
The left and right borders of the image correspond to north (0° or 360° respectively).
The middle of the image corresponds to south (180°).

Any even plane cutting through the borehole will show a trace of a sinusoid shape on the planar image. (The natural traces may show shapes that are slightly different from a mathematically correct sinus curve, if the plane has no even surface).

The "amplitude" of this trace is determined by the dip of the plane. The horizontal positions of the maximum and the minimum of the trace are determined by the dip direction of the plane.

The dip direction and dip of the visible structures are measured by manually placing best fitting sinusoids on the structures. The measured sinusoids are displayed in the images. Different symbols and colours are used for the different types of structures. Each sinusoid has an index number.

Equal area projections representing the structural features can be generated.

The projections show dip and dip direction in the SCHMIDT NET, LOWER HEMISPHERE. Joints, layer boundaries and the foliation can be represented separately in additional diagrams for each borehole.

An ASCII table with the index number, orientation, depth and the type of each structure is generated.

A full suite of borehole logging probes is available including

  • Optical borehole scanner (OPTV)
  • Acoustic televiewer (BHTV)
  • Flow meter (fluid logging)
  • Wire line water sampling at particular DepthFluid temperature
  • Fluid conductivity
  • Calliper
  • Natural gamma-ray (total count)
  • Spectral gamma-ray
  • Sonic (FWS, CBL)
  • Borehole deviation (magnetic and gyro)
  • Total magnetic field (Hx, Hy, Hz)
  • Resistivity and IP
  • Dual induction rock conductivity
  • Density (gamma – gamma)
  • Porosity (neutron)

Survey of all hole orientations

  • Vertical up
  • Vertical down
  • Horizontal and inclined