Optimisation of Ultra-Deepwater Pipeline Design, Construction and Pre-Commissioning

摘要

Ultra-deepwater hydrocarbon pipelines face a number of designchallenges in the form of demanding geotechnical characteristics of theselected route, extreme slope, construction loads arising from suspendedcatenary and loads introduced during conventional hydrotesting of theinstalled pipeline.The paper details the design, manufacturing and construction approachadopted by the Turkstream project to eliminate hydrotest requirements.Following completion of pipelay, both pipelines were pre-commissionedwith multiple cleaning pigs propelled by compressed Nitrogen andbatches of mono-ethylene glycol (MEG) as desiccant for the moistureentrapped in the pipeline during construction.