Author Archives: Frédérique Boël

Behind the curtains of SAGE Profile 2.6: taking care of corrosion

Unprotected carbon-manganese steel pipelines are susceptible to corrosion, which can jeopardize its structural integrity and eventually lead to failure. Hence, accounting for the effects of internal and external corrosion is essential during the design of an offshore pipeline.

As we strive to shape SAGE Profile according to our client’s needs and challenges, we are currently working on a brand-new feature allowing to model the effects of internal corrosion.

In SAGE Profile 2.6, the corrosion rate will be estimated based on the pipeline content, and internal corrosion will be modeled as a progressive loss of wall thickness. This new capability will enable the simulation of ageing pipelines, where the corrosion allowance has been consumed.

SAGE Profile is stepping up to simulate pipeline walking

Deepwater HPHT pipelines are generally susceptible to significant end expansion and axial walking. Pipeline walking can cause cumulative axial displacement of the entire pipeline, which can induce damage at termination units, expansion spools and riser tie-ins. The rate of walking depends not only on the temperature profiles, but also on the magnitude of axial resistance, the mobilization distance and the seabed topography.

In this paper, Filip Van den Abeele, Jean-Christophe Ballard and Charles de Brier from Fugro GeoConsulting (Belgium) present parametric FE analyses performed with SAGE Profile. The results indicate that the powerful pipe-soil interaction library of SAGE Profile is capable of accurately capturing the phenomenon of axial walking

More sophisticated axial pipe-soil responses, derived from the SMARTPIPE measurements, were implemented to assess the impact on the predicted and expansion walking rate. The axial pipe-soil interaction was captured by a tri-linear soil spring, and the effects of mobilization distance, peak friction factor and residual friction factor were evaluated by performing sensitivity analyses. Moreover, the tri-linear soil spring in SAGE Profile allows distinguishing between the initial (first loading) stiffness, the unloading stiffness and the reloading stiffness.

>> Read more – 2013

Dynamic simulations of trawl gear impact with SAGE Profile

SAGE Profile has been designed to assist the pipeline engineer during the entire lifecycle of an offshore pipeline. The software suite has been certified by Bureau Veritas for static applications like on-bottom stress analysis, out-of-straightness analysis, span assessment,… In a paper, recently presented at the 6th Pipeline Technology Conference, the use of SAGE Profile to simulate dynamic events like trawl gear interference was demonstrated.

In the paper, numerical models are presented to simulate the displacements and corresponding stresses during trawl gear pull-over. The finite element analyses are compared with simplified analytical approaches and results published in DNV-RP-F111. The results indicate that SAGE Profile can indeed predict the transient dynamic response of subsea pipelines subjected to trawl gear pull-over loading – provided the damping factors are judiciously chosen.

Based on these observations, we shall submit SAGE Profile for full dynamic certification and the development team is keen on introducing trawl gear interference (as per DNV-RP-F111) as a new load pattern in forthcoming versions of SAGE Profile.

>> Read more – 2013