title: Flow Assurance in NeqSim description: “Guide to NeqSim flow-assurance screening for hydrates, wax, asphaltenes, scale, corrosion, erosion, emulsions, and pipeline cooldown.” —

Flow assurance keeps hydrocarbon fluids transportable during production, shutdown, and restart. NeqSim combines thermodynamic models with screening calculators for identifying risks and comparing mitigation options. Treat screening results as input to an engineering assessment, not as design certification.

Choose a workflow

Topic Start here
Integrated overview Flow-assurance overview
Hydrates Hydrate models
Wax Wax characterization
Asphaltenes Asphaltene modeling
Pipeline cooldown, corrosion, scale, and wax curves Screening tools
Sand erosion Erosion prediction
Emulsions Emulsion viscosity
High-salinity scale and chemical treatment Mineral-scale and chemical-treatment validation

Screening classes

The following classes are in neqsim.pvtsimulation.flowassurance.

Class Purpose
PipelineCooldownCalculator Lumped-parameter pipeline shutdown cooldown
DeWaardMilliamsCorrosion Screening-level CO2 corrosion rate
ScalePredictionCalculator Saturation indices for common mineral scales
PitzerScaleActivityModel Activity coefficients for high-salinity brines
MultiMineralScaleEquilibrium Coupled, shared-ion mineral precipitation
WaxCurveCalculator Wax fraction curves with monotonicity enforcement
ErosionPredictionCalculator API RP 14E velocity and DNV RP O501 erosion screening
EmulsionViscosityCalculator Effective viscosity and phase-inversion screening

For the fuller NORSOK M-506 and M-001 workflows in neqsim.process.corrosion, see the corrosion analysis module.

Quick start: De Boer asphaltene screening

The De Boer method is a fast empirical screen based on reservoir undersaturation and in-situ oil density. Pressures in this example are absolute bar and density is in kg/m3.

import neqsim.pvtsimulation.flowassurance.DeBoerAsphalteneScreening;
import neqsim.pvtsimulation.flowassurance.DeBoerAsphalteneScreening.DeBoerRisk;

DeBoerAsphalteneScreening screening =
    new DeBoerAsphalteneScreening(350.0, 150.0, 750.0);

DeBoerRisk risk = screening.evaluateRisk();
double riskIndex = screening.calculateRiskIndex();

System.out.println("Risk category: " + risk);
System.out.println("Risk index: " + riskIndex);

For these inputs, the current correlation returns MODERATE_PROBLEM and a risk index of 1.6. This classification is a screening result; confirm a flagged fluid with laboratory data and a fitted thermodynamic model.

Select an asphaltene method

Need Class or guide Notes
Fast empirical screen DeBoerAsphalteneScreening Requires reservoir pressure, saturation pressure, and in-situ density
CPA stability analysis AsphalteneStabilityAnalyzer See CPA calculations
Compare available methods AsphalteneMethodComparison or AsphalteneMultiMethodBenchmark See method comparison
Regular-solution model FloryHugginsAsphalteneModel Configure and calibrate for the fluid being studied
Refractive-index screen RefractiveIndexAsphalteneScreening Requires measured or estimated refractive-index inputs
Cubic-EOS characterization PedersenAsphalteneCharacterization Adds characterized pseudo-components and supports binary-interaction tuning
CPA parameter fitting AsphalteneOnsetFitting See parameter fitting
Pressure-onset flash neqsim.thermodynamicoperations.flashops.saturationops.AsphalteneOnsetPressureFlash Run the flash object and read getOnsetPressure()
Temperature-onset flash neqsim.thermodynamicoperations.flashops.saturationops.AsphalteneOnsetTemperatureFlash Run the flash object and read its onset result

The PhaseType enum includes ASPHALTENE for a solid asphaltene-rich phase and LIQUID_ASPHALTENE for the liquid-liquid Pedersen approach. Phase appearance and type depend on the selected model, enabled phase checks, composition, and flash conditions; do not assume that adding an asphaltene component alone guarantees a precipitated phase.

NeqSim includes an asphaltene database component for CPA workflows. Its default parameters are generic starting values. For cubic-EOS workflows, PedersenAsphalteneCharacterization creates case-specific pseudo-components. Tune either approach to measured onset or precipitation data before using it for design decisions.

Asphaltene documentation