Radioactive Logging Apparatus for Complex Investigations of Near-Surface Rocks

Abstract

Summary At the Institute of Geophysics of the National Academy of Sciences of Ukraine a modern technology has been created for investigation of grounds (near-surface rocks). The purpose of technology is solution of engineering geological problems, including seismic microzonation. Technology is based on the methods and apparatus of radioactive logging, which involves neutron-neutron logging (NNL), gamma-gamma density logging (DL) and gamma-ray logging (GR). The abstract presents the results of the development of radioactive logging apparatus as an integral part of the new technology. Prototype three-component tool 2NNL+DL+GR, surface control and registration console were developed and produced on the basis of the modern elemental base. The created apparatus increases the productivity and efficiency of logging operations by reducing the number of trips, digital recording, storage and transmission of information, and by using the computer programs for processing and interpreting the results of borehole measurements. The effectiveness of the developed apparatus, together with the appropriate metrological and interpretation-methodical support, has been demonstrated on specific example of borehole investigations. The technology allows to determine the following engineering geophysical parameters: total density, dry ground density, content of shale, porosity, volume moisture, water saturation factor, groundwater level, etc.