Log analysis shows that log responses are practically influenced by various distortions conditions. Evaluation of porosity by log data is complicated due to difficulties in rock identification, its polymineral composition, resulting anomalies in logging curves. It is noted that identification of dyke intervals, alterated rocks and zones with abnormally high voids is only possible when all geological and log data are available and used in complex. Possibility of using the method of balanced porosity based on corrected data of acoustic, neutron-neutron, density and SGR logs for further application of volumetric method is examined. Possibility of SP curve using for identification massive vuggy-fractured, altered reservoirs on the basement is shown