Shallow Water Pipeline Stability Assessment Our deepwater engineering expertise and quick thinking applied to a shallow water pipeline helped an operator in Brazil demonstrate integrity and prevented costly remedial measures. REGION Offshore Brazil WATER DEPTH 10m-100m Background A major pipeline installed by one of our clients in Brazil was designed to be trenched and backfilled along the section approaching the shore, in water depths ranging from 10m to 100m. Due to discrepancies between the design and actual soil data, problems occurred during trenching operations in very soft and very rocky regions of soil, and two sections of the pipeline became fully exposed. One 74m long uncoated pipeline section in 60m water depth protruded from the seabed, and one 1350m long cement-coated section in 10m water depth sat fully on the seabed. Our client required urgent engineering work to determine if the exposed pipeline was unstable or susceptible to dynamic effects which would require stabilising with concrete mattresses or other forms of intervention. Assessing Integrity In order to assess the stability and fatigue performance of the exposed pipe sections, we collated all appropriate data from the client and modelled the section of the pipeline from the known fully-entrenched sections to the partially submerged and fully exposed regions. We quickly conducted static and dynamic on-bottom stability checks, as well as vortex induced vibration fatigue and wave induced fatigue analyses of the free-spanning sections to assess the integrity of the fully exposed pipe. . Results The engineering work proved that the exposed pipeline sections would not be at risk of lateral deflection or excessive levels of fatigue during its lifetime and that no costly remedial measures needed to be taken. This was a welcome conclusion for our client and provided them with the justification and confidence that the pipeline could be left as installed. Although somewhat different from our typical deepwater project scopes, the broad range of experience, logical thinking and engineering expertise of our team in Brazil meant that we were able to apply our methods to a shallow water problem, helping the client get an answer quickly and within budget. Share this page Share on FacebookShare on LinkedinShare on Twitter Projects Holistic Conductor Structural Assessment Using WellCat Gulf of Suez Minimum Facilities Platform Installation Wind Farm Pre-Piling Template Analysis North Sea Platform Well Conductor Failure STREAM JIP – Leveraging Riser Field Data Large-Scale Riser Field Tests Related TECHNICAL PAPER Challenges in Shallow Water Riser Design for FPSOs Installed in Campos Basin TECHNICAL PAPER New Approach for Assessment of Flexible Risers Interference in Shallow Waters