Flow assurance
Abercus has undertaken a wide range of flow assurance projects using a combination of simulation approaches. For simpler one-dimensional scenarios considering the dynamic behaviour within long lengths of pipeline,
for example, tools such as OLGA/Ledaflow or Abercus' own FAST suite may be appropriate. For scenarios where local effects due to more complex three-dimensional geometry is of interest, CFD and/or FEA may be the tools of choice.
The two approaches may also be coupled, with a large-scale one-dimensional model coupled to and providing boundary conditions for a local more detailed three-dimensional simulation.
Application areas include:
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hydraulic analysis of pipelines - the assessment of flow regime, liquid hold-up, slugging propensity/frequency, liquid surge, wall shear stress, temperature, condensation rate, corrosion
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thermal assessment of complex three-dimensional geometries to assess heat losses during normal operations and cool down times following the cessation of flow -
this is important for hydrate/wax avoidance and the associated design and optimisation of thermal insulation
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pigging operations
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erosion due to solids carried by the flow - location of erosion hot-spots and rate of erosion over the life of the field
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compressible flow and Joule-Thomson cooling effects - low-temperature qualification during start-up
and assessment of associated thermally-induced stress
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valve behaviour - prediction of pressure-loss Cv curves during steady operation and simulation of dynamic valve closure
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flow-induced vibration (FIV) - vibration/structural loading/fatigue life assessment due to loading induced by internal flow
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positioning of sampling probes in accordance with ISO3171.
Thermal assessment of complex geometries
For complex three-dimensional geometries such as that shown for the example below, classical engineering calculations and simpler one-dimensional methods are not able to properly capture the important physics and heat transfer mechanisms, and so 3D CFD is the tool of choice.
Pigging operations
Abercus uses CFD to predict the fluid dynamics within pipeline junctions during pigging operations, to
predict the forces exerted upon the pig by the fluid and the surrounding pipeline wall and assess the risk of pig loss due to frictional resistance following any reduction in fluid thrust as the pig moves through the junction.
The fluid/pipeline forces can subsequently be assess using FEA to optimise the structural design of the pig.
