Pipes¶

Pipes define axial geometry: where flow moves, where gravity acts, and where heat is exchanged with formation, seawater, atmosphere, or a coupled service line. Each pipe is split into segments, and each segment is discretized into cells for the 1D solver.

Production and Service Lines¶

Two segment arrays can be present:

Production line: main multiphase path (wellbore, flow line, riser).
Service line: auxiliary gas/service path (gas-lift, circulation).

JSON keys:

Production: productionPipe (EN) · dutosProducao (PT)

Service: servicePipe (EN) · dutosServico (PT)

Common segment fields:

active / ativo, id / id, crossSectionId / idCorte

Inclination¶

Inclination controls hydrostatic pressure and strongly influences flow patterns.

Direct Angle Mode¶

The segment angle is given directly relative to the horizontal.

JSON key: angle (EN) · angulo (PT) — unit: radians

Angle convention follows flow direction even when geometry indexing is reversed:

JSON key: geometryFollowsFlow (EN) · sentidoGeometriaSegueEscoamento (PT)

XY Reconstruction Mode¶

If XY mode is active, inclination is inferred from segment endpoints:

JSON keys: xCoor, yCoor (EN/PT) Requires initialConfig.xyMode / configuracaoInicial.modoXY set to true.

Segment Thermal Context¶

Each segment can exchange heat with formation, ambient fluid, or a thermally coupled pipe.

Cross-Section and Formation References¶

JSON keys:

Cross section: crossSectionId (EN) · idCorte (PT)

Formation: formationId (EN) · idFormacao (PT)

Ambient Medium Type¶

JSON key: environment (EN) · ambienteExterno (PT) Values: 0 = user-defined medium, 1 = seawater, 2 = atmosphere

Convection Direction¶

JSON key: convectionDirection (EN) · direcaoConveccao (PT) Values: 0 = transversal, 1 = longitudinal

Thermal Coupling with Service Line¶

Production segments can be coupled to service-line segments.

JSON key: thermalCoupling (EN) · acoplamentoTermico (PT)

Engine/validation behavior:

Coupling is segment-level, not cross-section-level.
Coupling requires service line enabled (gasLine / linhaGas true).
Coupled segments should coincide in position, length, and discretization.

Initial and Ambient Profiles per Segment¶

Profiles inside initialAndAmbientConditions / condicoesIniciaisEAmbiente are defined at relative positions from 0 to 1.

Position key: measuredPosition (EN) · compInter (PT)

Initial-condition profiles (transient, `initialCondition = 0`)¶

JSON keys:

Pressure: pressure · pressao

Temperature: temp · temp

Holdup: holdup · holdup

Complementary fraction: complementaryFluidFraction · bet

Superficial liquid velocity: usl · uls

Superficial gas velocity: usg · ugs

Service-line specific initial profile:

Gas mass flow: gasMassFlowRate · vazaoMassicaGas

Ambient/external profiles¶

JSON keys:

Ambient temperature: ambientTemp · tempExterna

Ambient velocity: ambientVel · velExterna

Ambient conductivity: ambientConductivity · kExterna

Ambient specific heat: ambientSpecificHeat · calorEspecificoExterno

Ambient density: ambientDensity · rhoExterno

Ambient viscosity: ambientVisc · viscExterna

Ambient profiles are conditionally required depending on formationId, environment, and thermalCoupling.

Discretization¶

Grouped blocks (default)¶

JSON keys: grouping: true (agrupamento: true) and discretization / discretizacao

numCells · nCelulas

length · comprimento [m]

Explicit cell sizes¶

JSON key: cellDx (EN) · dxCelula (PT) when grouping = false

XY mode cell count¶

JSON key: numCellsXY (EN) · nCelulas_XY (PT)

Example: Simple Horizontal Production Segment¶

{
  "initialConfig": {
    "gasLine": false,
    "xyMode": false
  },
  "productionPipe": [
    {
      "id": 0,
      "active": true,
      "crossSectionId": 0,
      "formationId": 0,
      "angle": 0.0,
      "environment": 1,
      "grouping": true,
      "discretization": [
        {"numCells": 50, "length": 20.0}
      ],
      "initialConditions": {
        "measuredPosition": [0.0, 1.0],
        "ambientTemp": [4.0, 4.0],
        "ambientVel": [0.3, 0.3]
      }
    }
  ]
}

Example: Coupled Production/Service Segments¶

{
  "initialConfig": {
    "gasLine": true,
    "xyMode": false
  },
  "productionPipe": [
    {
      "id": 0,
      "active": true,
      "crossSectionId": 0,
      "angle": -1.57079632679,
      "formationId": 0,
      "thermalCoupling": 1,
      "grouping": true,
      "discretization": [
        {"numCells": 40, "length": 10.0}
      ]
    }
  ],
  "servicePipe": [
    {
      "id": 0,
      "active": true,
      "crossSectionId": 1,
      "angle": -1.57079632679,
      "grouping": true,
      "discretization": [
        {"numCells": 40, "length": 10.0}
      ]
    }
  ]
}

Tip

Start with coarse cells (20-50 m) to validate setup, then refine near strong gradients (valves, pumps, major elevation changes, thermal-coupling regions).