The reasons of repeated many times gas and oil restocking at the fields being exploited in the Samara region

Since the late fifties constant increase in oil resourses has been observed at some fields being exploited in the Samara Region. The preliminary figures of oil resourses were recalculated twice after deeper drilling to obtain the mast precise data. Nevertheless the increase was observed, which seems to have no explanation. The authors of the work have made an attempt to consider the problem thoroughly and to ascertain the reasons if the phenomenon which is of great scientific and practical importance.