geophysical technology density and neutron loggings геофізична технологія apparatus apparent porosities combination of logging methods combination of neutron logging and density logging complex of gamma-ray complex of neutron-neutron logging engineering geophysical parameter engineering geophysical parameters gamma-gamma density logging and gamma-ray logging gas reservoirs gas saturation coefficient ground grounds (near-surface rocks) groundwater level identification of gas reservoirs interpretation methodology logging-while-drilling methodical and metrological assurance oil-and-gas borehole petrophysical parameter pressure-temperature conditions of occurrence seismic microzonation set of apparatus devices true porosity zone of aeration zone of saturation апаратура