The report presents the current state and prospective areas of research to determine the actual mechanical properties and chemical composition of metal pipes after long-term operation. The issues of development of standard, unified and special tests for the calculation and experimental determination of the characteristics of pipeline steels are considered, taking into account the accumulated long-term experience. The obtained dependencies are verified by carrying out equivalent tests at different scale levels: bench tests of field samples of new pipes and pipes after long-term operation, tests of full-thickness pipe elements with artificial and natural defects, and special laboratory tests. These studies are the base for determination the characteristics of strength, durability and safety of pipelines and are one of the basic elements of the pipeline pipeline reliability of oil and oil products.