A Review of Loading and Unloading on Intermediate Casting for Effective Support in Drilling Machine

Casing design is one of the most important aspects of drilling Engineering. It is a way of analysing stress for the wellbore. This paper aimed at providing a new method for optimal design of intermediate casing that can withstand a variety of external, internal, thermal, and self-weight loading, while at the same time being subjected to wear and corrosion for optimal well delivery. The methodology employed involves the assessment of pore pressure and fracture pressures for optimal casing seats selection, designing for burst, collapse and tension while considering other external loads. From the simulation carried out for the intermediate section of the well, it was only casing J9 for the case study well that satisfied the load conditions in terms of burst and collapse pressures. This study showed that casings should never be designed to their yield strength or tensile strength limits; instead a design factor should be used to estimate the strength of the casing so that the casing would not be loaded beyond its capacity.