Sonar Applications in Submerged Mine Workings
COLOG has adapted a multi-frequency profiling sonar probe that can be logged from any 4-conductor standard geophysical logging rig, for imaging submerged mine workings, large diameter shafts, raised bores, karst environments and large diameter boreholes. Much of the data collected from this new technology has been on high-profile projects – environmental studies at mine sites where a detailed evaluation of the old submerged mine workings is needed. Once the mine workings are mapped in detail with the sonar, a sophisticated flow-evaluation in the mine workings using dye-tracers or the colloidal borescope for horizontal flow measurements or the corehole dynamic flowmeter for vertical flow measurements is performed. In borehole applications the hydrophysical logging technique is typically used in conjunction with the sonar evaluation for a complete analysis of the conditions of the void spaces and the mass-balance of flow occurring through the open space.
