geophysical technology logging-while-drilling oil-and-gas borehole нафтогазова свердловина density and neutron loggings геофізична технологія apparatus apparent porosities combination of logging methods combination of neutron logging and density logging combination of radioactivity logging methods complex of gamma-ray complex of neutron-neutron logging critical proportions engineering geophysical parameter engineering geophysical parameters financial security and financial management gamma-gamma density logging and gamma-ray logging gas reservoirs gas saturation coefficient ground grounds (near-surface rocks) groundwater level identification of gas reservoirs input-output table interpretation methodology matrices of social accounts methodical and metrological assurance national accounts petrophysical parameter