Offshore Pipeline Technology for Deep Water and Rugged Seabed Applications

Offshore Pipeline Technology for Deep Water and Rugged Seabed Applications

By Marcelo Caire, Research Scientist, Marintek do Brasil; Egil Giertsen, Research Director, Marintek, Norway.

Pipelines are one of the solutions for gas transportation from the remote and deepwater pre-salt provinces. A 250 km pipeline which connects the Tupi Pilot System to the Mexilhao pipeline is already in place, and several other pipeline networks are under evaluation offshore Brazil. Considering the very deep water and the rugged and irregular seabed, advanced design and installation technology is required in order to make pipelines competitive to LNG, Compressed Gas and Gas to Liquid solutions, both with regard to cost and flexibility.

This advanced technology is now available in a software package called SIMLA. Driven by similar seafloor challenges encountered in the North and Norwegian Seas, the research institute MARINTEK (www.marintek.sintef. no) has developed the SIMLA software – a special purpose computer tool for engineering analysis of offshore pipelines during design, installation and operation.

SIMLA allows 3D visualization of the pipeline on the seabed, also including the results from structural response analyses. It features various models for pipe/ seabed interaction, control algorithms for feeding of pipe joints, 3D load model for current and nonlinear material model for the pipe in cases with significant plastic strain.

The SIMLA computer tool was first made available on desktop computers, and was shown to be a robust and efficient design tool. It has then been integrated onboard pipe-laying vessels for analysis and visualization during the lay operation. This provides valuable additional information such as catenary shape including


stresses in the pipe, lay tension, sagbed utilization, pipe tension and VIV at free spans and lateral stability. The first version of this 'online' system was successfully field tested during summer 2009 by Acergy at the Ormen Lange field in Norway.

The main "online" output from the tool is a visualization of:

  • the seabed with possible intervention work (dredging, rock supports, gravel carpets etc.), including the target route corridor for the pipe,
  • the measured position of the lay vessel, and corresponding computed configuration of the catenary,
  • the calculated contact forces acting on the pipe from seabed, rollers on the stinger, counteracts or other objects,
  • a set of online key parameters as curve plots (top- and lay-tension, lay-back, maximum curvature for the pipe, predicted deviation from target route, and utilized lateral capacity).

It is believed that this technology will help to secure safe and cost effective deepwater pipe lay installation operations also in Brazil. Not only because of the onboard system itself, but also because this technology allows for high quality training and familiarization prior to offshore installation.

For more information contact our local office in Brazil (http://www.marintek.com.br MARINTEK do Brasil, Rio de Janeiro, or This e-mail address is being protected from spambots. You need JavaScript enabled to view it. at our main office in Norway.

MARINTEK will be present at the Rio Oil&Gas 2010 exhibition, pavillon 4, 'Pavilhão Noruega'.

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