Typical environments foreseen in HPHT wells put a high challenge for properties required for materials. Strength levels create severe limitations to improve toughness, resistance to hydrogen embrittlement and other corrosive agents responsible of both general and localized corrosion. High temperature service reduces the alternatives, because of effect on corrosion and also the reduction in strength at temperature. Internal pressure and well depth create a combination of stress that would lead to requirements of heavy wall thickness for tubulars. This, in turn, is a challenge for seamless tubular manufacture with actual production routes, particularly in the field of hot deformation and heat treatment.
Progress has been made in the design and production of low alloy carbon steel that somehow has reached the limit of actual metallurgy science. Other material alternatives, in the field of stainless steels and other corrosion resistance alloys can be also explored.
Another particular point is the development of methods for properties assessment in the expected environments. The reproductions in laboratory conditions, and the correlation with those in the field, are areas of research and test development.
The paper shows the alternatives that exist in the field of material selection, through the comparative evaluation of mechanical and corrosion properties for a range of materials through normalized test procedures and other research activities.