Steel pipes in XXI century

Dr. Igor Yu. Pyshmintcev

 

TMK company

 

History and evolution of pipe manufacturing is presented with an analysis of new technical requirements to steel welded and seamless pipes. Main differences and limitations in technology and material selection for welded and seamless pipes are presented. High strength seamless pipes with thick wall and high alloyed steels for oil and gas drilling can be produced through careful material selection, hot rolling and strengthening by quench and tempering. High diameter to wall thickness ratio large diameter pipes are strengthened using thermomechanical processing technology for such initial flat product as coils or plates.
Main challenge of last decades is new parameters of oil and gas production with shift to deeper wells, corrosive environments related to high partial pressures of carbon dioxide and hydrogen sulfides in presence of chlorides and other dissolved ions. Different solutions in strengthening combined with better corrosion behavior were found as new grades of alloyed and stainless steels for seamless products. An improvement of resistance to sulfide stress cracking was achieved by combination of grain refinement and precipitation hardening in quench and tempered microstructure of medium carbon steels alloyed by chromium and molybdenum. High thermal stability of microstructure makes possible application of the steels at elevated temperatures due to high yield stress at maximum temperature 450 ^oC as well as at low temperatures minus 60 ^oC a high Charpy toughness is obtained. Remarkable resistance to CO₂ corrosion is typical for 13% Cr martensitic stainless steels. To improve strength-low temperature Charpy relationship typical for standard 0,20%C-13%Cr the low carbon and nickel alloying concept of 13Cr steel was used. Lower carbon content was resulted in excellent low temperature Charpy energy and in good corrosion resistance in typical corrosive environments.
New application of these steels was found for thermal insulated pipes designed for next generation of oil production technologies. Hundred hydrocarbon fields have been discovered in the Bazhenov-Neocomian oil system in Western Siberia where large in-place resources were found in unconventional, self-sourced reservoir organic-rich rocks. Rocks treatment by superheated water for fast transformation of kerogens to oil is one of the ways for future involvement of these resources in production. High strength of vacuum insulated tubes for 450 ^oC and 40 MPa pressure were developed and tested using chrome-moly steel for outer pipe and special stainless martensitic steel for internal one. Special attention is paid to welding of two different grades, to thermal stresses caused by temperature difference and to reliability of well string.
Efficiency of long range energy transportation is related to hydrocarbon linepipes, LNG shipping and high voltage electrical lines. Gas transportation in spite of long history of pipeline construction of has several perspectives for cost saving. Long history of development in high grade steels application and consequently a higher working pressures for pipelines is focused to technology and strategy of reliability. The last includes resistance to ductile running fracture resulted from high hoop stresses, high energy of compressed methane, decreased plasticity of new grades. New effects of microstructure on fracture mechanism and crack arrestability strongly dependent on microstructure and texture were revealed. New high strength pipes were developed for application at 11,8 and 14,71 MPa working pressure. Reliability of new grades for long gas transportation is proven by full scale burst tests and laboratory criterions were developed. Total weigh of steel for construction can be reduced. Special effects can be reached due to increase of line productivity by 20 - 50 % and reduced number of compressor stations as well as energy losses.