Meet us at the Offshore Pipeline Technology Conference (OPT2015) in Amsterdam

The SAGE Profile team will be present at the 38th edition of the Offshore Pipeline Technology Conference (25th and 26th February 2015, Amsterdam) and preceding seminar on Pipeline Global Buckling Design (24th February).

During the seminar, we will discuss an integrated numerical approach to design offshore pipelines susceptible to either upheaval or lateral buckling.

Join us at the Fugro booth for a prime-time demo of the new SAGE Profile 3.0, and to meet our geotechnical engineers and pipeline consultants. We look forward to meeting you there!

SAGE Profile explores fully bonded pipe-in-pipe systems

Thanks to their exceptional thermal insulation capability, Pipe-in-Pipe (PIP) systems are well suited for the transportation of hydrocarbons at high pressure and high temperatures (HP/HT), preventing hydrate formation and ensuring high discharge temperatures at the arrival facility.

In this whitepaper resulting from a close interaction between Fugro GeoConsulting, Genesis Oil and Gas and different Universities, Filip Van den Abeele reviews and compares different numerical approaches to simulate the structural response of a pipe-in-pipe system. The fully bonded PIP system can be simulated using an equivalent diameter approach, replacing both pipes by a single pipe with an equivalent mass and bending stiffness. This approach has been pursued to evaluate the mechanical response of a PIP system in a free span. A formulation is presented to reconstruct the stress distributions in the inner and outer pipes based on the strains and bending moments calculated for the equivalent cross section. The results show that the equivalent pipe section methodology can be used for on-bottom roughness analysis and free span assessment of fully bonded Pipe-in-Pipe systems.

Free Spanning Pipe in Pipe: Benchmark between SAGE Profile 3D and Abaqus

>> Read more – 2014

Meet us at the International Pipeline Conference (IPC2014) in Calgary

At the 10th edition of the International Pipeline Conference (IPC2014), our senior pipeline consultant Filip Van den Abeele will present a paper on structural reliability of free spanning pipelines. The paper covers a risk based evaluation of free spans, by applying the principles of structural reliability theory to the problem of long free spanning pipelines subjected to vortex induced vibrations.

Abstract: Structural Reliability of Free Spanning Pipelines

Filip Van den Abeele, Frédérique Boël and Jean-François Vanden Berghe, Fugro GeoConsulting Belgium

When installing subsea pipelines on an uneven seabed, the free spans can be vulnerable to fatigue damage caused by vortex induced vibrations (VIV). Indeed, even moderate currents can induce vortex shedding, alternately at the top and the bottom of the pipeline, at a rate determined by the flow velocity. Each time a vortex sheds, a force is generated in both the in-line and cross-flow direction, causing an oscillatory multi-mode vibration. This vortex induced vibration can give rise to fatigue damage of submarine pipeline spans, especially in the vicinity of the girth welds. Traditional design for VIV is recommended in DNV-RP-F105, which limits the allowable free span length and implies whether (and when) seabed interventions are required.

Continue reading →

Simulations of upheaval buckling reveal explosive results

Rock dumping of untrenched pipelines is generally undertaken to increase the lateral or upheaval resistance of the pipeline to buckling. While it is important to understand the increased resistance to lateral loading provided by the rock berm, it is also essential to capture the influence of the underlying soil on this resistance, which can be critical to the design sizing of the berm.

The latter point is illustrated in the paper presented by Jean-Christophe Ballard at the latest Offshore Pipeline Technology Conference (OPT 2014) in Amsterdam. The paper presents soil structure interaction analyses performed to aid in the design of a rock berm to provide restraint to a surface laid pipeline in the case of full bore rupture of the line. The motivation behind this analysis was the planned removal of an unexploded World War II mine, which was located against a high pressure gas transmission pipeline. The purpose of the analysis was to identify the suitability of application of a rock berm restraint to stabilise the pipeline in the event of an explosion.

Since soil conditions at the location consisted principally of soft clay, the analyses highlighted the significant influence of the soft soil layer on rock berm stability under lateral pipeline loading. It has also been demonstrated that upheaval buckling problems can be conveniently modeled in Sage Profile 3D through inclusion of a backfill soil spring in addition to the three conventional pipe-soil interaction springs.

>> Read more – 2014

Cranfield students explore lateral buckling with SAGE Profile

SAGE Profile, the market leader software suite for offshore pipeline analysis, is used worldwide for on-bottom roughness analyses, free span evaluation and on-bottom stress analyses. The latest versions of the software are increasingly being used to tackle more complex pipeline problems, like upheaval buckling, pipeline walking and lateral buckling. Recently, the pipeline engineering students at Cranfield University have demonstrated the ability of SAGE Profile to predict susceptibility to lateral buckling

During their research assignment for the M.Sc. in Ocean and Offshore Technology, the pipeline engineering students at Cranfield University performed SAGE Profile simulations of lateral buckling on a full 3D Digital Terrain Model. The SAGE Profile results compared well with analytical approximations (Hobbs theory) and the Abaqus benchmark.

Different methods to fire an engineered buckle were explored, like introducing (dual) sleepers, adding buoyancy modules, locally reducing seabed friction factors, or performing snake lay simulations. The results indicated that SAGE Profile can be used to evaluate the susceptibility to lateral buckling for high pressure, high temperature pipelines and flowlines.

Lateral buckle triggered at sleeper location in SAGE Profile 3D Viewer

Cranfield students with Filip Van den Abeele