Neqsim Subsea And Wells

Well Design

Casing Design (API 5C3 / NORSOK D-010)

SubseaWell well = new SubseaWell("Producer-1", stream);
well.setWellType(SubseaWell.WellType.OIL_PRODUCER);
well.setCompletionType(SubseaWell.CompletionType.CASED_PERFORATED);
well.setRigType(SubseaWell.RigType.SEMI_SUBMERSIBLE);

// Geometry
well.setMeasuredDepth(3800.0);
well.setTrueVerticalDepth(3200.0);
well.setWaterDepth(350.0);
well.setMaxWellheadPressure(345.0);
well.setReservoirPressure(400.0);

// Casing program
well.setConductorOD(30.0);          well.setConductorDepth(100.0);
well.setSurfaceCasingOD(20.0);       well.setSurfaceCasingDepth(800.0);
well.setIntermediateCasingOD(13.375); well.setIntermediateCasingDepth(2500.0);
well.setProductionCasingOD(9.625);    well.setProductionCasingDepth(3800.0);
well.setTubingOD(5.5);
well.setTubingWeight(23.0);
well.setTubingGrade("L80");

// Barrier elements (NORSOK D-010 two-barrier principle)
well.setPrimaryBarrierElements(3);
well.setSecondaryBarrierElements(3);
well.setHasDHSV(true);

// Drilling schedule & costs
well.setDrillingDays(45.0);
well.setCompletionDays(25.0);
well.setRigDayRate(540000.0);

// Mechanical design
well.initMechanicalDesign();
WellMechanicalDesign design = (WellMechanicalDesign) well.getMechanicalDesign();
design.calcDesign();
design.calculateCostEstimate();

// Results
double burstDF = design.getProductionCasingBurstDF();     // >= 1.10
double collapseDF = design.getProductionCasingCollapseDF(); // >= 1.00
double tensionDF = design.getProductionCasingTensionDF();   // >= 1.60
boolean barrierOk = design.isBarrierVerificationPassed();
double totalCost = design.getTotalCostUSD();
String json = design.toJson();

API 5CT Casing Grades

NORSOK D-010 Design Factors

SURF Cost Estimation

SURFCostEstimator

SURFCostEstimator surf = new SURFCostEstimator();
surf.setRegion(SubseaCostEstimator.Region.NORWAY);
surf.setNumberOfWells(4);
surf.setFlowlineLength(25.0);       // km
surf.setUmbilicalLength(27.0);      // km
surf.setWaterDepth(350.0);          // m
surf.setTreeType("vertical");
surf.setHasManifold(true);
surf.setManifoldWells(4);
surf.setHasRiser(true);
surf.setRiserType("flexible");

double surfCapex = surf.estimate();  // USD
String breakdown = surf.toJson();    // Detailed cost breakdown

Regional Cost Factors

Tieback Analysis

Workflow

1. Define the satellite field (reservoir, fluid, wells)
2. Define candidate host facilities with available capacity
3. Configure tieback options (distance, diameter, insulation, boosting)
4. Screen flow assurance (hydrate margin, arrival temperature, pressure drop)
5. Estimate SURF CAPEX for each option
6. Rank by NPV or unit technical cost

Usage

TiebackAnalyzer analyzer = new TiebackAnalyzer();

// Define host
HostFacility host = new HostFacility("Platform Alpha");
host.setAvailableCapacity(30000.0);   // boe/d spare capacity
host.setProcessingPressure(70.0);     // bara
host.setLocation(61.5, 2.5);         // lat, lon

// Define options
TiebackOption opt1 = new TiebackOption("Direct Tieback");
opt1.setFlowlineLength(15.0);
opt1.setFlowlineDiameter(10.0);
opt1.setWaterDepth(350.0);
opt1.setInsulationType("wet_insulation");

TiebackOption opt2 = new TiebackOption("Boosted Tieback");
opt2.setFlowlineLength(30.0);
opt2.setFlowlineDiameter(12.0);
opt2.setWaterDepth(450.0);
opt2.setHasBooster(true);
opt2.setBoosterType("multiphase_pump");

analyzer.setHost(host);
analyzer.addOption(opt1);
analyzer.addOption(opt2);
analyzer.setFluid(reservoirFluid);

TiebackReport report = analyzer.analyze();
// report contains: pressure drop, arrival temperature, hydrate margin,
// SURF cost, NPV ranking, flow assurance verdict per option

Subsea System Configuration

Complete Subsea Layout

SubseaProductionSystem subseaSystem = new SubseaProductionSystem("Field Layout");
subseaSystem.setNumberOfWells(6);
subseaSystem.setWaterDepth(400.0);
subseaSystem.setFlowlineLength(30.0);     // km to host
subseaSystem.setUmbilicalLength(32.0);    // slightly longer routing
subseaSystem.setRiserType("flexible");
subseaSystem.setTreeType("horizontal");
subseaSystem.setHasManifold(true);
subseaSystem.setManifoldWells(3);          // 2 manifolds × 3 wells
subseaSystem.setHasPigLoop(true);
subseaSystem.setHasInLineTee(false);
subseaSystem.setHasSubseaBooster(true);
subseaSystem.setBoosterType("compressor"); // or "pump"

Flowline and Pipeline Sizing

Steady-State Pipe Flow

// Beggs & Brill multiphase correlation
PipeBeggsAndBrills pipeline = new PipeBeggsAndBrills("Export Line", feedStream);
pipeline.setLength(50000.0);           // m
pipeline.setDiameter(0.508);           // m (20 inch)
pipeline.setPipeWallRoughness(5e-5);   // m
pipeline.setAngle(0.0);               // horizontal
pipeline.setNumberOfIncrements(50);

// With formation temperature gradient (subsea/buried)
pipeline.setFormationTemperatureGradient(4.0, -0.03, "C");
// 4°C at seabed, -0.03 °C/m depth gradient

pipeline.run();
double pressureDrop = feedStream.getPressure() - pipeline.getOutletPressure();
double arrivalTemp = pipeline.getOutletTemperature() - 273.15;  // °C

Pipeline Mechanical Design

AdiabaticPipe pipe = new AdiabaticPipe("Pipeline", feedStream);
pipe.setLength(50000.0);
pipe.setDiameter(0.508);

PipelineMechanicalDesign mechDesign =
    (PipelineMechanicalDesign) pipe.getMechanicalDesign();
mechDesign.setMaxOperationPressure(150.0);
mechDesign.setMaterialGrade("X65");
mechDesign.setDesignStandardCode("DNV-OS-F101");
mechDesign.calcDesign();

double wallThickness = mechDesign.getWallThickness();  // mm
String report = mechDesign.toJson();

Artificial Lift Screening

ArtificialLiftScreener alScreener = new ArtificialLiftScreener();
alScreener.setReservoirPressure(250.0);     // bara
alScreener.setWaterDepth(350.0);
alScreener.setGOR(200.0);                   // Sm3/Sm3
alScreener.setWaterCut(0.30);
alScreener.setDepth(3000.0);                // m TVD
alScreener.setProductionRate(5000.0);       // boe/d

// Screen all methods
Map<String, String> recommendations = alScreener.screen();
// Returns: {"ESP": "RECOMMENDED", "Gas Lift": "FEASIBLE",
//           "Rod Pump": "NOT_RECOMMENDED", ...}

Gas Lift Design

GasLiftCalculator gasLift = new GasLiftCalculator();
gasLift.setWellDepth(3000.0);
gasLift.setReservoirPressure(250.0);
gasLift.setProductionRate(5000.0);
gasLift.setGLR(500.0);                    // Sm3/Sm3
gasLift.setInjectionPressure(150.0);      // bara

double optimalGLR = gasLift.calculateOptimalGLR();
double injectionRate = gasLift.calculateInjectionRate();

// Multi-well gas lift optimization
GasLiftOptimizer optimizer = new GasLiftOptimizer();
optimizer.addWell(well1, gasLift1);
optimizer.addWell(well2, gasLift2);
optimizer.setTotalGasAvailable(500000.0);  // Sm3/d
Map<String, Double> allocation = optimizer.optimize();

Design Standards Reference

Common Subsea Design Pitfalls