Offshore Pipeline Soil Interaction Parameters and Scour Evaluation, Middle East
GR8 GEO provided estimates of scour and pipeline-soil interaction (PSI) parameters to be used for the
design of an offshore crude oil pipeline system in the Middle East. GR8 GEO performed the following tasks for the project:
• Seabed and shallow subsurface characterization that included the interpretation of the seabed and shallow subsurface conditions based on available geophysical and geotechnical data. The pipeline route was then subdivided into zones based on similar characteristics and a range of parameters for each zone was estimated.
• Estimation of monotonic PSI inputs for buried pipelines including the evaluation of as-laid pipeline embedment and generation of parameters for before/after backfill. The PSI inputs included axial and lateral resistance estimates, PSI stiffness in vertical direction, and vertical load penetration response (installation case).
• Estimation of monotonic PSI Inputs for exposed pipelines including the evaluation of pipe embedment after laying, development of equivalent axial friction coefficients for thermal expansion and lateral buckling analyses, development of equivalent lateral friction coefficients for lateral buckling analyses, PSI stiffness in vertical direction and vertical load penetration response curves for free spanning analyses.
• Liquefaction triggering evaluation analyses using empirical correlations based on available borehole and CPT data
• Scour assessment including geomorphological assessment of sediment mobility, geotechnical model for scour assessment, metocean parameters for scour assessment, selection of scour assessment method and scour calculations