It is shown, that nonobservance of deep well drilling technology under complex conditions, providing for well-bore cleaning from cuttings and caved-in rocks, leads to gradual accumulation of solid particles, which, in the end, leads to development of complications. Presented are examples of complications and means of their elimination in some wells of North Caucases and other regions of the country. It is noted, that development of complications in the wells is promoted by high hydrodynamic pressures, occuring during trips to change bit. Well drilling technology for complex conditions has been produced in SevKavNIPineft, which enables not only to cope with complications, but to increase drilling rates and footage per bit.