Pipeline Corrosion Integration

The NORSOK corrosion analysis module integrates directly with NeqSim’s pipeline mechanical design system. After running a pipeline simulation, you can automatically extract operating conditions from the process stream and run a complete corrosion assessment.

Architecture

Pipeline / PipeBeggsAndBrills / AdiabaticPipe
  └── PipelineMechanicalDesign
        ├── NorsokM506CorrosionRate  ← CO2 corrosion rate
        ├── NorsokM001MaterialSelection  ← Material & CA
        └── PipeMechanicalDesignCalculator  ← Wall thickness with CA

Data Flow

  1. Pipeline.runCorrosionAnalysis() delegates to PipelineMechanicalDesign
  2. PipelineMechanicalDesign.runCorrosionAnalysis() extracts from the outlet stream:
    • Temperature (°C) and pressure (bara)
    • CO2 and H2S mole fractions from gas phase
    • Liquid density and viscosity (after initPhysicalProperties())
    • Flow velocity from flow rate and pipe diameter
  3. Runs NorsokM506CorrosionRate.calculate()
  4. Feeds results to NorsokM001MaterialSelection.evaluate()
  5. Applies the resulting corrosion allowance (mm) to the wall thickness calculator

Usage via Pipeline Convenience Methods

The simplest approach — call methods directly on the pipeline equipment:

import neqsim.thermo.system.SystemSrkEos;
import neqsim.process.equipment.stream.Stream;
import neqsim.process.equipment.pipeline.PipeBeggsAndBrills;
import neqsim.process.processmodel.ProcessSystem;

// Create fluid with CO2
SystemSrkEos fluid = new SystemSrkEos(273.15 + 60.0, 100.0);
fluid.addComponent("methane", 0.85);
fluid.addComponent("ethane", 0.05);
fluid.addComponent("CO2", 0.03);
fluid.addComponent("H2S", 0.001);
fluid.addComponent("water", 0.069);
fluid.setMixingRule("classic");
fluid.setMultiPhaseCheck(true);

Stream feed = new Stream("feed", fluid);
feed.setFlowRate(50000.0, "kg/hr");

PipeBeggsAndBrills pipe = new PipeBeggsAndBrills("export pipeline", feed);
pipe.setLength(50000.0);      // 50 km
pipe.setDiameter(0.254);      // 10 inch
pipe.setAngle(0.0);

ProcessSystem process = new ProcessSystem();
process.add(feed);
process.add(pipe);
process.run();

// Configure corrosion parameters
pipe.setDesignLifeYears(25);
pipe.setInhibitorEfficiency(0.0);  // No inhibitor
pipe.setGlycolWeightFraction(0.0);

// Run corrosion analysis
pipe.runCorrosionAnalysis();

// Read results
System.out.println("Corrosion rate: " + pipe.getCorrosionRate() + " mm/yr");
System.out.println("Material: " + pipe.getRecommendedMaterial());
System.out.println("CA: " + pipe.getRecommendedCorrosionAllowanceMm() + " mm");

Pipeline Convenience Methods

Method Description
runCorrosionAnalysis() Run full M-506 + M-001 analysis from stream data
setDesignLifeYears(double) Set design life (default 25 years)
setInhibitorEfficiency(double) Set inhibitor efficiency (0.0 – 1.0)
setGlycolWeightFraction(double) Set glycol fraction (0.0 – 1.0)
getCorrosionRate() Get calculated rate (mm/yr)
getRecommendedMaterial() Get material recommendation
getRecommendedCorrosionAllowanceMm() Get CA (mm)

Usage via PipelineMechanicalDesign

For more control, access the mechanical design directly:

PipeBeggsAndBrills pipe = new PipeBeggsAndBrills("pipeline", feed);
// ... configure and run pipeline ...

pipe.initMechanicalDesign();
PipelineMechanicalDesign design =
    (PipelineMechanicalDesign) pipe.getMechanicalDesign();

// Configure corrosion parameters
design.setDesignLifeYears(25);
design.setInhibitorEfficiency(0.80);
design.setGlycolWeightFraction(0.0);

// Run corrosion analysis
design.runCorrosionAnalysis();

// Access the models directly for detailed results
NorsokM506CorrosionRate corrosionModel = design.getCorrosionModel();
NorsokM001MaterialSelection materialSelector = design.getMaterialSelector();

System.out.println("pH: " + corrosionModel.getCalculatedPH());
System.out.println("Fugacity: " + corrosionModel.getCO2FugacityBar() + " bar");
System.out.println("Sour: " + corrosionModel.isSourService());
System.out.println("SCC risk: " + materialSelector.getChlorideSCCRisk());

// JSON reports
System.out.println(corrosionModel.toJson());
System.out.println(materialSelector.toJson());

PipelineMechanicalDesign Methods

Method Description
getCorrosionModel() Access NorsokM506CorrosionRate instance
getMaterialSelector() Access NorsokM001MaterialSelection instance
runCorrosionAnalysis() Auto-populate from stream and run both models
setDesignLifeYears(double) Design life for CA calculation
setInhibitorEfficiency(double) Inhibitor efficiency (0–1)
setGlycolWeightFraction(double) Glycol weight fraction (0–1)
getCorrosionRate() Corrected rate (mm/yr)
getRecommendedMaterial() Material recommendation
getRecommendedCorrosionAllowanceMm() CA (mm)

Combined Mechanical + Corrosion Design

Run corrosion analysis alongside wall thickness sizing:

pipe.initMechanicalDesign();
PipelineMechanicalDesign design =
    (PipelineMechanicalDesign) pipe.getMechanicalDesign();

// Set mechanical design parameters
design.setMaxOperationPressure(100.0);
design.setMaterialGrade("X65");
design.setDesignStandardCode("DNV-OS-F101");

// Run corrosion analysis first (sets CA on the calculator)
design.setDesignLifeYears(25);
design.runCorrosionAnalysis();

// Now run mechanical design (uses the corrosion-derived CA)
design.calcDesign();

// Wall thickness includes corrosion allowance
String report = design.toJson();

Effect on Inhibitor

Compare uninhibited vs. inhibited corrosion rates:

// Without inhibitor
pipe.setInhibitorEfficiency(0.0);
pipe.runCorrosionAnalysis();
double uninhibitedRate = pipe.getCorrosionRate();

// With 80% inhibitor
pipe.setInhibitorEfficiency(0.80);
pipe.runCorrosionAnalysis();
double inhibitedRate = pipe.getCorrosionRate();

System.out.println("Uninhibited: " + uninhibitedRate + " mm/yr");
System.out.println("Inhibited: " + inhibitedRate + " mm/yr");
System.out.println("Reduction: " + (1 - inhibitedRate/uninhibitedRate)*100 + " %");

Python Example

from neqsim import jneqsim

SystemSrkEos = jneqsim.thermo.system.SystemSrkEos
Stream = jneqsim.process.equipment.stream.Stream
PipeBeggsAndBrills = jneqsim.process.equipment.pipeline.PipeBeggsAndBrills
ProcessSystem = jneqsim.process.processmodel.ProcessSystem

# Create fluid
fluid = SystemSrkEos(273.15 + 60.0, 100.0)
fluid.addComponent("methane", 0.85)
fluid.addComponent("CO2", 0.03)
fluid.addComponent("water", 0.12)
fluid.setMixingRule("classic")
fluid.setMultiPhaseCheck(True)

feed = Stream("feed", fluid)
feed.setFlowRate(50000.0, "kg/hr")

pipe = PipeBeggsAndBrills("pipeline", feed)
pipe.setLength(50000.0)
pipe.setDiameter(0.254)

process = ProcessSystem()
process.add(feed)
process.add(pipe)
process.run()

# Run corrosion analysis
pipe.setDesignLifeYears(25)
pipe.runCorrosionAnalysis()

print(f"Rate: {pipe.getCorrosionRate():.2f} mm/yr")
print(f"Material: {pipe.getRecommendedMaterial()}")
print(f"CA: {pipe.getRecommendedCorrosionAllowanceMm():.1f} mm")