Flow assurance & multiphase modelling

Flow assurance is fundamental to the safe, reliable, and economic operation of oil and gas production systems. NavierFlow US provides flow assurance engineering and multiphase modelling to help operators understand how fluids behave across wells, pipelines, flowlines, and processing facilities under both steady-state and transient conditions.

By combining industry-standard 1D multiphase simulation tools like OLGA, with targeted CFD where equipment-level detail is required, we deliver physics-based insight into hydrate risk, slugging, corrosion, chemical inhibition, and operational stability across the full life of an asset.

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Steady-state and transient flow assurance analysis

We perform steady-state and transient flow assurance studies to define operating limits and identify risks associated with multiphase transport. Our work supports both greenfield developments and brownfield modifications.

Typical applications include:

• Multiphase pipeline and flowline modelling
• Pressure-drop and flow capacity assessments
• Turndown and low-rate operability studies
• Liquid holdup and accumulation analysis
• Flow regime identification across operating envelopes
• Sensitivity studies to rate, composition, and temperature

These analyses form the backbone of flow assurance decision-making for subsea tiebacks, long-distance pipelines, and gas-condensate systems.

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Hydrate risk, MEG injection, and thermal management

Hydrate formation remains one of the most critical flow assurance risks in offshore and cold-environment systems. We quantify hydrate risk and define robust mitigation strategies to ensure safe operations.

Our services include:

• Hydrate formation envelope assessment
• MEG injection and inhibition requirement modelling
• Lean and rich MEG thermodynamic effects
• MEG line pressure-drop and deliverability analysis
• Insulation performance and heat-loss assessment
• Cooldown and cold-start feasibility studies

These studies support operational planning during startup, shutdown, and extended outages. This approach aligns with established industry guidance from organisations such as DNV.

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Slugging, terrain effects, and flow stability

Multiphase systems operating over undulating terrain are susceptible to unstable flow regimes that can limit production or exceed facility constraints.

We assess:

• Terrain-induced slugging risk
• Severe slugging tendencies
• Liquid fallback and accumulation mechanisms
• Slug volume and frequency relative to separator capacity
• Operating envelopes for stable production

Our outputs allow operators to define safe rate limits and identify mitigation measures early in design or operations.

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Shutdown, cooldown, and restart analysis

Transient operating scenarios often define the true operability of a system. We model shutdown, cooldown, and restart behavior to assess feasibility under realistic thermal and hydraulic conditions.

Typical assessments include:

• Cooldown temperature profiles and hydrate risk
• Settled-out pressure analysis
• Restart feasibility under partial or full cooldown
• Impact of insulation, MEG strategy, and operating procedures

These studies are critical for defining restart windows and minimizing downtime risk.

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Corrosion and chemical inhibition modelling

Flow assurance and corrosion risk are tightly coupled in multiphase systems. We support corrosion assessments by integrating hydraulic, thermal, and chemical effects into a single modelling framework.

Our capabilities include:

• Internal corrosion risk assessment linked to flow regime
• Water wetting and liquid holdup evaluation
• Corrosion inhibitor injection modelling
• Chemical distribution and delivery effectiveness
• Sensitivity of corrosion risk to operating conditions

This approach supports the development of robust corrosion management and inhibition strategies aligned with real flow behavior. Our corrosion and erosion assessments are informed by established industry guidance, including recommendations published by the American Petroleum Institute (API), ensuring that modelling outputs are aligned with accepted velocity limits and integrity considerations used across the oil and gas industry.

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CFD support for flow assurance challenges

CFD is applied where local flow behavior governs performance, integrity, or risk. We use CFD to complement 1D flow assurance models when higher spatial resolution is required.

Typical CFD applications include:

• Separator and scrubber performance
• Inlet device optimization
• Phase distribution and maldistribution
• Sand transport and erosion risk
• High-velocity erosion hotspots
• Thermal behavior of process equipment

CFD results are integrated into the broader flow assurance context rather than treated in isolation.

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Energy transition flow assurance

As energy systems evolve, many of the most challenging flow assurance problems remain rooted in fluid transport, thermal behaviour, and transient operability. We apply our flow assurance and multiphase modelling expertise to low-carbon and emerging energy systems where these challenges are critical.

Our experience includes:

• Carbon capture, utilization, and storage (CCUS)
  CO₂ pipeline hydraulics, dense-phase transport, thermal behavior, and transient operations, including shutdown and restart considerations.
• Blue hydrogen production and transport
  Flow assurance support for hydrogen-rich streams, including thermal management, pressure-drop behaviour, and integration with existing gas infrastructure.
• Hydrogen and CO₂ transportation systems
  Assessment of operability, material temperature limits, and transient risks associated with new fluid properties and operating envelopes.

By applying proven flow assurance methods to emerging energy systems, we help operators manage technical risk while supporting decarbonization objectives.

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Typical deliverables

Our flow assurance studies provide clear, actionable outputs, including:

• Hydrate and thermal operating envelopes
• MEG and chemical injection requirements
• Slugging risk and stability assessments
• Restart and cooldown feasibility limits
• Pressure-drop and capacity evaluations
• Corrosion risk insights linked to flow behavior
• CFD-supported equipment performance assessments

All deliverables are structured to support engineering decisions and operational planning.

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Where we support

We provide flow assurance and multiphase modelling services for:

• Subsea tiebacks and offshore flowlines
• Long-distance multiphase pipelines
• Gas-condensate and wet-gas systems
• Offshore topsides and onshore facilities
• Brownfield modifications and life-extension projects

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Ready to discuss a flow assurance challenge?

If you are facing hydrate risk, slugging instability, corrosion concerns, or operability limits, our team can help you define safe, reliable operating strategies.