Helica – helix stress analysis (illustration: DNV GL)
A joint industry project run by DNV GL has replicated stresses measured in an umbilical subjected to tension and bending in full-scale tests, further validating the accuracy of the analysis software Helica. DNV GL’s Helica can analyse thousands of simulations in a matter of minutes, improving engineering efficiency and significantly reducing design cost.
Subsea engineers calculate stresses in umbilicals and flexible pipes using software to ensure that individual components will not fail. Such failures could lead to costly production shut-downs or hydrocarbon leaks. DNV GL’s Helica software, which calculates stresses in umbilical and flexible pipe components, has now been proven to deliver highly accurate results through a joint industry project (JIP). Helica has previously been verified against publicly available data. The JIP compared stresses calculated using Helica with measured stresses in a full-scale umbilical sample subjected to tension and bending, and the analysis results correlated remarkably well with the test data.
“As far as we know, this is the first time anyone has been able to demonstrate such a remarkably strong correlation between analysis results and such high quality stress measurements in full-scale subsea umbilicals,” says Nils Sødahl, Vice President, Riser Technology, DNV GL – Oil & Gas. The JIP, which included Ultra Deep LCC, ExxonMobil, Oceaneering, Shell, Technip and ABB, based its research on data provided by ExxonMobil. “We are very grateful to ExxonMobil for contributing stress measurements to the JIP and giving us this opportunity,” adds Sødahl.
Helica is a highly efficient cross-section analysis tool that calculates mechanical properties, capacities, and fatigue of umbilicals and flexible pipes. Based on these analyses, engineers can optimise design and save cost not only in the design stage, but throughout the lifecycle of the subsea system. Helica can perform thousands of simulations in a matter of minutes, whereas subsea engineers relying on the industry’s most commonly used finite element analysis (FEA) tools today may spend hours to build a model and perform a simulation of a single load case.
“We strongly believe that Helica will be the new industry standard for stress and fatigue analysis of flexible pipes and umbilicals,” says Are Føllesdal Tjønn, CEO DNV GL – Software.
DNV GL simultaneously launched Helica 2.5, featuring a new module for extreme capacity checks and a new interface to commonly used global analysis software, such as Orcaflex, Riflex and Flexcom.