Two discretisation methods have been proposed recently for the simplification of detailed gas-condensate pipeline elevation profiles (1). Both methods preserve the hydrodynamic behaviour of the original detailed profile and produce a suitable simplified profile for the dynamic simulation of multiphase flows. A number of operators and engineering companies have been evaluating and, in some cases, using these methods for the design of world-class multiphase transport systems. The first part of this paper summarises the key lessons learned from these first applications and concludes with a set of recommendations for the simplification of detailed pipeline elevation profiles in the context of dynamic simulation of multiphase flows.
A comprehensive analysis of seabed surveys and as-laid bottom-of-pipe profiles has revealed that non-dimensional large-scale indicators can be used to develop a sensible basis for the characterisation and complexification of elevation profiles. The second part of this paper introduces a new complexification methodology which proposes to increase the roughness of coarse elevation profiles by means of non-dimensional indicators. Correlations for the determination of roughness indicators are proposed for various geographical areas.