Project Overview
The Malampaya deep-water gas-to-power project signalled the birth of the natural gas industry in the Philippines. It delivers up to 20% of the country’s electricity requirements using indigenous resources of natural gas, the cleanestburning hydrocarbon, and reduces the need for imported oil. Phases two and three have sustained levels of gas production in recent years, helping to maintain national energy security.
Both Malampaya Twin Phase Flowlines are shown to have walked in the axial direction 1.8m at a rate of .28mm per cycle, resulting in severe stresses at the PLES. We developed the pipe clamping mattress (PCM) in conjunction with Shell to arrest further pipeline axial walking.
MMA Scope
Detailed design and supply of concrete mattresses for axial stabilisation of TPF1.
- 15x PCM (2.75m x 4m x 0.5m, 9.1Te)
- 15x Log Mattress (2.5m x 5m x 0.6m, 11.8Te)
Prior to fabrication, MMA completed a full-scale System Integration Test (SIT) at our Australian fabrication yard. MMA was awarded a Shell Certificate of Excellence, and later, the sole global licence for the now Shell patented Pipe Clamping Mattress.
Outcome
We created an alternative method to suction piles for pipeline walking mitigation resulting in significantly lower material costs and no requirement for heavy lift transport and installation vessel.
This alternative method to rock dumping suits locations where there is no local rock or presence of flexible fallpipe vessels. It reduced material costs compared to rock or standard mattresses.
PCMs allow MMA to tailor the pipeline mitigation strategy to more efficiently address the specific issues faced on each project. With the PCM solution, it is possible to define, visualise and target the most efficient placement points enabling less load (and fewer materials) for an improved outcome.
Another benefit of PCMs is that they can be used as a ‘wait and see’ approach. PCMs do not need to be installed during pipelay but can be used only if axial walking is observed during the design life of the pipeline.
Technical Details
| Description |
Dimensions (m) |
Min. Weight in air (Te) |
Min. Density (kg/m3) |
| PCM |
L 2.75 x W 4 x H 0.5 |
9.31 |
2400 |
| Log Mattress |
L 2.5 x W 5 x H.06 |
11.64 |
2400 |
Key Equipment / Installation Method
The PCM transfers 100% of the ballast directly onto the pipeline. This targeted approach reduces over 60% of materials compared to rock dumping and standard concrete mattresses. This reduced material need allows the use of lower-spec vessels, reducing logistics and installation costs and time.
MMA Innovation / Value Added
PCMs were surveyed at 12 months post-installation and no further pipeline walking was observed, it had been completely arrested. Due to the success of this deployment, a second campaign of PCMs was installed on the second 16” pipeline.
For more information on our pipeline walking mitigation services offering, please contact our team at:
Blue Solutions
+61 8 9431 7431
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