Stress Analysis, Integrity Management & Guaranteed Life Extension

Onshore and offshore pipelines, risers, umbilicals, and cables

by Incorporation of Advanced Soil Interaction Effects

  • Orcintech‘s strength when offering integrity solutions is that we understand the fluid-soil-structure interaction and its influence on stress analysis for ECA, integrity, and life extension of onshore and offshore pipelines, risers, umbilicals, and cables.

Did you know:

In subsea catenary risers, umbilicals, and cables:

  • the fatigue life of catenary risers, umbilicals, and cables in the touchdown zone may significantly depend on complex seabed interaction that is rarely incorporated into the design because of a range of uncertainties.
  • a trench is formed in the touchdown zone of the catenary risers, umbilicals, or cables due to cyclic remolding of the seabed soil.
  • there is still no coherent agreement in the literature about the beneficial or detrimental effect of trench formation and seabed soil stiffness evolution.
  • the increase or decrease of the fatigue life can be from tens to hundreds of percent?
  • the beneficial or detrimental effect of seabed soil interaction on the fatigue life case-dependent and heavily affected by the dominance of low-frequency motions of the floating system?
  • the incorporation of seabed interaction effects may completely eliminate the need for a painful sequential riser relocation strategy for spreading the fatigue damage.
  • the incorporation of a relocation strategy for mitigating the damage accumulation without considering the seabed interaction effects may even reduce the fatigue life of the system.
  • some of the software used in the worldwide riser, umbilical, and cable analysis has dynamic instability bugs in modeling non-linear hysteretic seabed interaction.
  • the consolidation effects that are not considered in seabed interaction analysis may or may not increase the fatigue damage by several tens of percent?

In onshore and offshore pipelines:

  • The incorporation of an advanced pipeline-soil interaction in stress analysis as a prerequisite of Engineering Critical Assessment (ECA) may have a significant effect on the cost reduction of weld repairs.
  • the stochastic and probabilistic approach for the selection of pipeline-soil interaction parameters may significantly reduce the construction and maintenance costs. 

What we do:

  • For subsea catenary risers, umbilicals, and cables:

Our two decades of extensive research and development efforts have resulted in a deep understanding of the complex seabed interaction effects on the fatigue life of catenary risers, umbilicals, and cables. As part of this long journey, we have developed in-house data collection and modeling tools to turn these threatening uncertainties associated with system oscillation, seabed properties, seabed interaction, and system structural response into opportunities. We collect the field data of environmental loads, seabed soil characteristics, and seabed interaction properties and incorporate them into a digital twin of the system comprising advanced 3D finite element models and AI algorithms to accurately assess the influence of seabed interaction on the fatigue life of risers, umbilicals, and cables. Eventually, using the assessment results, we provide sophisticated operation strategies to achieve a guaranteed life extension. 

  • For onshore pipelines and offshore pipelines/risers/umbilicals/cables:

we incorporate the advanced pipeline-soil interaction effects into the stress analysis to improve the accuracy of ECA and widen the flaw acceptance criteria to mitigate the construction and maintenance cost. Also, we perform a fit-for-service analysis by improving the selection of geotechnical input parameters using all the geotechnical site investigation and laboratory testing reports along with site-specific calculation methods combined with Monte Carlo simulations and optimization procedures to mitigate the construction and maintenance costs.    

How we do this:

Orcintech‘s innovative solution to mitigate the uncertainties and accurately assess the effect of soil interaction on the stress analysis for ECA, integrity, and fatigue life of pipelines, catenary risers, umbilicals, and cables comprises several new developments as follows:

For subsea catenary systems:

  • AUVs equipped with SBP, SSS, and Magnetometers for an autonomous subsea survey of the touchdown zone and features of trench formation
  • Motion loggers for accurate assessment of floating system oscillations, particularly low-frequency excursions
  • Cyclic ball penetrometers for re-assessment of seabed soil parameters for incorporation into nonlinear hysteretic seabed interaction models
  • A 3D seabed interaction model for the incorporation of the realistic surveyed data into the fatigue analysis
  • A fit-to-purpose advanced finite element model and post-processing tools for fatigue analysis of the catenary system
  • Advanced AI and ML algorithms, and optimization tools for determining the best operation strategies for a guaranteed life extension.

Advanced Numerical Modeling Capabilities

Besides the assessment of soil interaction effect on the stress analysis, life extension, and integrity of onshore and offshore pipelines, risers, umbilicals, and cables, Orcintech performs advanced finite element analysis and numerical modeling using state-of-the-art modeling codes developed in-house for:

  • Fluid-soil-structure interactions
  • Advanced constitutive soil modeling 
  • Ice-seabed-seawater-structure interaction
  • Non-linear geometric and material properties
  • Rate-dependent monotonic, cyclic, and dynamic material response
  • Multi-component contact interaction and friction
  • Multi-body dynamic systems and vibrations
  • Coupled Eulerian-Lagrangian, and sequential large deformation analysis
  • Thermal loading, creep, and fatigue loads
  • Multiphase flow-induced system vibrations

and much more.

Advanced Experimental Model Testing

Orcintech provides creative and innovative research services to engineering challenges in oceans, rivers, lakes and marine environments. Our headquarter is located in St. John’s, Newfoundland and Labrador, Canada. We have access to the world-class sophisticated testing facilities in our neighborhood at C-CORE, NRC, and Memorial University. The facilities include a range of hydraulic flumes, towing tanks, offshore basins, centrifuge facilities, cold rooms, Ice basin, wind tunnels, etc. We identify, adapt, and integrate advanced solutions to improve the safety, integrity, and performance of coastal, marine, and offshore systems through experimental approaches such as :

  • Small-scale geotechnical centrifuge model testing
  • Large, and full scale physical model testing in offshore basins
  • Field works, data collection, and data mining

Professional Training

Critical thinking & Problem solving

World-class training in advanced offshore engineering practice

Orcintech provides advanced online professional training in practical offshore engineering analysis and design challenges. Short courses and workshops are organized based on a core concept of critical thinking and problem solving. Develop your offshore engineering skills through world-class state-of-the-art and state-of-the-practice with no need to physical attendance. Visit our academy for a broad range of opportunities.