Subsea flowline buckle capacity considering uncertainty in pipe–soil interaction

Two probabilistic methods for evaluating the initial buckling capacity of subsea flowlines are described. The methods represent the seafloor strength as either a random homogenous material or one developed from a spatially correlated random field. The investigations include the random nature of flowline embedment and out-of-straightness, both of which influence the flowline buckle capacity. The two methods are used in an example illustrating the probability of buckle formation for a simple flowline problem. The example application results in a comparatively small range of buckle capacity, which would otherwise be difficult to substantiate based on deterministic design space selections.