High performance tubulars for critical oil country applications and improved process for their preparation

摘要

A high performance carbon steel tubular for critical Oil Country applications and an improved process for its preparation are disclosed. The tubular is particularly adapted for use in deep wells where the tubular may be subjected to high pressure, wide temperature ranges, and/or corrosive environments, which may include hydrogen sulfide, carbon dioxide, and brine water, together with hydrocarbons. The process comprises forming a bloom from a modified 41XX killed steel, upset forging and piercing the steel bloom into a cylindrical extrusion billet, cold machining the inside and outside diameters of the extrusion billet to be concentric and cold machining the nose of the extrusion billet, reheating and extruding the billet to form an extruded shell, intercritically heat treating the shell, removing surface defects, cold working the tubular shell to finished dimensions, intercritically heat treating the sized tubular, and quenching and tempering the finished tubular.