Extending your reach
The premise is simple: Matrix LGS® free span remediation solutions extend your reach and allow you to operate in environments where you couldn't normally. Designed for use across cylindrical geometries in water currents, the system’s passive and low profile disrupts boundary layer instability caused by vortex induced vibration (VIV), making it an ideal solution for reducing amplitude, drag and VIV fatigue on pipeline free spans strong currents.
Matrix is a registered trademark of AMOG Technologies Pty Ltd.
- Reduces amplitude, drag and VIV fatigue
- Lower drag profile compared to other VIV reduction solutions
- Smaller cross sectional area than helical strakes allows for closer proximity to seabed topography
- Incorporating profile into buoyancy reduces costs and requirements for secondary equipment attachments
- Subtle, robust profile facilitates easier defouling processes
- Subtle, robust profile is deployment friendly
- LGS® profile can be incorporated into insulation moulding
- Easily retrofittable
- Field proven
Matrix LGS® - Proven and tested
- Brochure: Matrix LGS® VIV and drag reduction for SURF
- Leaflet: Matrix LGS® VIV and drag reduction for SURF
- Case study: Pipeline free span remediation
- Press release: Successful LGS® field deployment validates product's capability in offshore operations
Paper (2018): Mitigation of pipeline free span fatigue due to vortex induced vibration using longitudinally grooved suppression
Jayasinghe, K., Marcollo, H., Potts, A.E., Dillon-Gibbons, C., Kurts, P., and Pezet, P., Proceedings of the ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering OMAE2018, Madrid, Spain, June 17-22, 2018.
Irregular seabed bathymetry around subsea pipelines can lead to the formation of pipeline free spans. When exposed to on-bottom currents these free spans can be subject to Vortex- Induced Vibration (VIV), with consequential effects on the fatigue life of the pipeline. Traditional VIV suppression technologies such as strakes and fairings present installation challenges and durability concerns due to the significant increase in overall diameter associated with the geometric profiles of strakes and fairings.
Longitudinally Grooved Suppression (LGS) technology was developed from a concept stage through to field deployment on active drilling risers (Johnstone et. al., OMAE 2017) . The low profile and VIV suppression abilities of LGS present an opportunity for a more effective and operationally beneficial VIV suppression solution for pipeline free spans. Based on existing Class guidance for assessing pipeline free spans, a simplified framework for assessing free spans with LGS under a response based approach is presented. The simplified assessment implied a suppression efficiency (reduction in vibration amplitude) of up to 80%. An alternative comparative analysis using a force based approach was also performed in SHEAR7 of a bare pipeline and a LGS-wrapped pipeline. The requirements for qualification of new VIV mitigation technologies are also addressed and an example of an actual field installation of the device is presented, on an existing pipeline free span with low seabed clearance.
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