DNV-RP-F104 CO2 pipeline transport-envelope screening

DnvRpF104Co2PipelineEnvelopeScreeningKernel provides a narrow deterministic screen for the current DNV-RP-F104 2021-02+AMD:2021-09 basis. It compares a project composition and ordered pressure-temperature profile with caller-controlled composition limits, a maximum allowable operating pressure (MAOP), design temperatures, and externally derived single-phase pressure boundaries. Every result has SCREENING maturity and requires engineering review. It is not a DNV conformity decision and does not reproduce licensed criteria.

DNV describes F104 as a framework for the design, construction, and operation of onshore and offshore CO2 pipelines, with emphasis on structural assessment and supplementation of referenced pipeline standards. The DNV-RP-F104 publisher page lists edition 2021-02, amended 2021-09. Use the purchased document and project-controlled requirements register for applicability, criteria, composition specification, thermodynamic basis, materials, fracture control, construction, operation, safety, and requalification.

Calculation boundary

For actual and project-limiting mole fractions, NeqSim reports:

\[m_{CO_2}=x_{CO_2,actual}-x_{CO_2,min}\] \[m_{water}=x_{water,max}-x_{water,actual}.\]

At each ordered profile point $i$, the caller supplies operating pressure $P_i$, temperature $T_i$, and an externally established minimum pressure boundary $P_{single,i}$ for the intended single-phase transport region. The kernel reports four transparent margins:

\[m_{single,i}=P_i-P_{single,i}, \qquad m_{MAOP,i}=P_{MAOP}-P_i\] \[m_{T,min,i}=T_i-T_{design,min}, \qquad m_{T,max,i}=T_{design,max}-T_i.\]

The minimum-pressure interpretation is not a universal phase classifier. The caller must verify that pressure above each supplied boundary represents the intended single-phase region for the project composition, temperature, path, EOS, and uncertainty basis. NeqSim deliberately does not substitute the pure-CO2 critical point for a composition-specific phase envelope.

Runnable Java example

StandardEdition edition = StandardEdition.defaultEdition(StandardType.DNV_RP_F104);
DnvRpF104Co2PipelineEnvelopeScreeningKernel.Input input =
    DnvRpF104Co2PipelineEnvelopeScreeningKernel.Input
        .builder(edition, "Pipeline")
        .co2MoleFraction(0.98)
        .minimumCo2MoleFraction(0.97)
        .waterMoleFraction(0.0001)
        .maximumWaterMoleFraction(0.0002)
        .otherImpuritiesWithinProjectSpecification(true)
        .designMinimumTemperatureK(273.15)
        .designMaximumTemperatureK(323.15)
        .maximumAllowableOperatingPressurePaAbsolute(15.0e6)
        .addOperatingPoint(new DnvRpF104Co2PipelineEnvelopeScreeningKernel.OperatingPoint(
            "inlet", 0.0, 14.0e6, 293.15, 10.0e6))
        .addOperatingPoint(new DnvRpF104Co2PipelineEnvelopeScreeningKernel.OperatingPoint(
            "outlet", 100000.0, 10.5e6, 283.0, 9.5e6))
        .co2PipelineApplicabilityVerified(true)
        .compositionAndSpecificationVerified(true)
        .thermodynamicModelVerified(true)
        .singlePhaseBoundaryInterpretationVerified(true)
        .operatingProfileVerified(true)
        .pressureTemperatureLimitsVerified(true)
        .materialsCorrosionAndFractureBasisVerified(true)
        .safetyConstructionOperationsAndRequalificationReviewed(true)
        .build();

EngineeringCalculationResult<DnvRpF104Co2PipelineEnvelopeAssessment> result =
    new DnvRpF104Co2PipelineEnvelopeScreeningKernel().calculate(input, null);
Map<String, Object> report = result.getValue().toMap();

For these demonstration inputs, the CO2 fraction margin is 0.01 mole fraction, the water margin is 0.0001 mole fraction, and the minimum pressure margin above the caller-controlled single-phase boundary is 1.0 MPa. These are project-controlled demonstration values and deterministic regression data, not limits or benchmark values taken from F104.

The executed notebook uses the same API, plots the operating profile against the supplied phase boundary and MAOP, retains a below-boundary case as a visible finding, and demonstrates fail-closed behavior when the thermodynamic evidence flag is absent.

Fail-closed evidence boundary

Calculation is blocked unless all of the following are explicit and internally valid:

A negative composition or operating-envelope margin is a visible calculated finding, not a hidden readiness blocker. Verification flags are attestations: controlled calculations, specifications, records, uncertainties, and accountable approvals remain external evidence.

Requirement-pack routing

F104 spans more than one equipment calculation. Its StandardRequirementPack therefore maps six existing NeqSim capabilities with explicit boundaries:

Capability NeqSim implementation Boundary
CO2 phase behaviour ThermodynamicOperations Property/phase calculation; composition, EOS validation, uncertainty, and acceptance are external
Pipeline hydraulics PipeBeggsAndBrills Hydraulic/thermal model; CO2 validation and transients are external
Dense-CO2 corrosion DensePhaseCO2Corrosion Legacy heuristic screen only; embedded typical values are not F104 criteria
Mechanical design PipeMechanicalDesignCalculator Preliminary containment screen; F104 and DNV-ST-F101 load cases remain external
Impurity monitoring ImpurityMonitor Model composition monitor; analyser and response requirements remain external
Release consequence GasDispersionAnalyzer Generic dispersion calculation; CO2 release physics, exposure, QRA, and response remain external

Discover the immutable mapping independently of the typed kernel:

StandardSelection selection = StandardSelection.strictRequirements(StandardType.DNV_RP_F104);
StandardRequirementPack requirements = StandardRegistry.requireRequirementPack(selection);

The pack is a capability map, not a clause register or statement of coverage.

Not implemented

The kernel and pack do not calculate or approve:

DensePhaseCO2Corrosion and CO2FlowCorrections.isDensePhase(...) remain useful legacy heuristics when their limitations are acceptable. Their embedded typical impurity thresholds and pure-CO2 critical-point check are not current-edition F104 evidence and must not populate this kernel’s verified project boundaries without an independent controlled basis.

Separation from DNV-ST-F101

F104 supplements referenced pipeline standards; this screen does not replace pipeline-system structural design. DNV-ST-F101 pressure containment, collapse, propagation buckling, local buckling, load interaction, fatigue, incidental/test pressure, de-rating, safety class, ovality, fabrication route, and installation-strain checks remain independently required.