In High Presure High Temperature (HPHT) environments, high differential pressures often lead to the use of high strength, thick-walled, and occasionally non-standard, casing.
High temperatures compound the design problem by reducing the yield strength of the casing steel, by causing significant thermal linear expansion of the steel, and by generating high pressures in sealed annuli due to thermal expansion of the trapped fluid.
The following areas should be given particular attention. They have been divided into factors which affect the load experienced by the casing, and factors which influence the capacity . . .