Status: Need is Closed

Pipeline Bundle Spacers: Reduce weight by design

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The flowlines and control lines within a pipeline bundle are supported and clamped by internal spacers, which are fabricated from steel and required in relatively large quantities; up to 2500 for a long bundle (circa 7.5km).


The challenge is for an SME to propose a solution that will ideally reduce both weight and costs. However, acceptable solutions may offer a reduced weight with costs maintained or vice versa.


We are looking to challenge the existing design approach to improve the efficiency of the complete bundle system. 

  • Reducing weight of a spacer has both direct (spacer) and indirect (bundle system) positive outcomes, related to buoyancy and overall bundle weight requirements and of course overall commercial advantages.
  • The spacer design also impacts costs directly (spacer unit cost) and indirectly through reduced bundle assembly time.


We currently utilise a standard approach for spacer design, which has been successfully developed and refined over the years. All pipeline bundles are bespoke, with different numbers and configurations of flowlines and control lines and hence different cross sections, with a correspondingly sized outer carrier diameter (ranging from circa 0.75m to 1.5m). Therefore, it follows that all spacer designs are bespoke.


The solution does not have to be a conventional spacer or indeed a spacer.


A typical bundle section is detailed in Figure 1 below



The current design typically comprises 3 parts as detailed in Figure 2 below:



Bundle Background:


Subsea 7 has been successfully designing, fabricating and installing pipeline bundle systems since 1980, with around eighty installed to date, mostly in the North Sea. This product integrates the required flowlines and control systems necessary for any subsea development, and assembles them within a steel carrier pipe; delivering considerable value and cost savings for a wide range of applications.


Design Parameters:


  • Pressure within carrier annulus normally up 20barg (but can consider up to 40barg)
  • Carrier annulus environment is nitrogen during installation and treated seawater during operations
  • Design life 10 to 40 years
  • Spacer clamping load (onto flowline) = 120kN
  • Spacer radial load = 100kN
  • Spacer out of plane load = 80kN


Key success Criteria
  • Weight reduction compared to standard spacer design
  • Cost reduction compared to standard spacer design
  • Meet critical design specifications
  • Spacer alternative
  • Similar or reduced lead time


Possible Approaches
  • Alternative materials
  • Alternative manufacturing method (for example, casting, forging, additive manufacturing, etc)
  • Alternative clamping method
  • Alternative assembly method / interface into bundle
  • Novel technologies
  • Technologies that may require further development*
  • Solutions from non-oil & gas industries

*Note – we are prepared to look at funding early stage technologies from universities, research centres etc. 


Approaches not of Interest
  • Increased unit weight
  • Increased unit price
  • Solution must not increase bundle assembly time and complexity
  • No closed sections


Due Date
Mar 10, 2017
Items to be submitted

We are looking for concise, non-confidential proposals. The proposal should:

  • Describe the technical approach. A strong technical content is preferred and should ideally include; information on the technological readiness of the proposal, any proof of concept data, reference to any peer reviewed publications  and potential route to commercialization.
  • Include a description of the responding organisation or team and their experience


Please use the Respond button in order to submit your proposal. We recommend:

  • Including a concise abstract summarising your submission
  • Attaching your proposal
  • Attaching any additional documents


Please note that only non-confidential information can be accepted. By submitting a response you confirm that the response does not contain any confidential information.


Client Point of Contact

Super User
Gavin McClafferty
Gallery Moderator(s)
Oliver Worsfold
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Area of Interest