Current oil exploration depths warrant the need for a better understanding of subsea pipeline collapse capacities. UOE produced line pipe serves as an industry standard, but possess features that can adversely affect collapse capacity. Cladded line pipe are used to prevent internal corrosion of line pipe but may have the ability to contribute to its load carrying capacity.
Necessary concepts and production methods are outlined. Further definition of key factors such as wall thickness, ovality, yield stress and initial circumferential stresses are considered.
Solution methodology involved analytical and finite element solutions. Verification against full scale test data is performed. Analytical solutions are compared and contrasted. Finite element simulations are performed using ABAQUS, including non-linear geometry. Non-linear isotropic material models are implemented, and loading scenarios are based on large deformation theory.
Graphical representation of results is presented together with discussions. The strengthening effect of cladded pipes is apparent, and can help reduce the current wall thickness criterion, which will help line pipe to be dimensioned more accurately.