Multiple boreholes across the site have been logged, reaffirming earlier fracture orientations, recorded when the mine was operational some two decades ago. The setups have provided unique challenges with vertical depths exceeding 1,000 meters, hole inclinations (up to 60°), wedge deflections and narrow internal hole diameters.
Televiewers consisting of the High Resolution Optical Televiewer® and High Resolution Acoustic Televiewer® have captured excellent continuous logs of orientated, high resolution unwrapped images of the local geology and fractures therein. By “picking” and classifying fractures from the image, Robertson Geo software has been able to generate strike and dip azimuths, providing stereonets (Rose and Wulff plots) to display the main fracture orientations in the boreholes.
The latest visit to site was to an underground borehole and required 4-by-4 access. The Optical Televiewer was requested, however the image returned to surface was insufficient for purpose. Further investigation revealed the cause was a hydrocarbon source rock which obscured the camera lens. Fortunately our Acoustic Televiewer, which instead relies on ultrasound, was not affected and generated an excellent image.
