Neqsim Field Development

NeqSim Field Development Skill

Comprehensive reference for oil & gas field development using NeqSim's field development framework. Covers the full lifecycle from discovery through decommissioning, with emphasis on concept selection, production forecasting, economics, and risk assessment.

Field Development Lifecycle (Decision Gates)

Workflow Orchestration

FieldDevelopmentWorkflow workflow = new FieldDevelopmentWorkflow("Field Name");
workflow.setStudyPhase(StudyPhase.FEASIBILITY);
workflow.setFidelityLevel(FidelityLevel.SCREENING);

// Set reservoir
ReservoirInput reservoir = new ReservoirInput();
reservoir.setFluidType("gas_condensate");
reservoir.setGIIP(1.5e9);  // Sm3
reservoir.setReservoirPressure(350.0);  // bara
reservoir.setReservoirTemperature(95.0);  // °C
reservoir.setRecoveryFactor(0.65);
workflow.setReservoirInput(reservoir);

// Set wells
WellsInput wells = new WellsInput();
wells.setNumberOfProducers(4);
wells.setWaterDepth(350.0);
wells.setTotalDepth(3800.0);
workflow.setWellsInput(wells);

// Set infrastructure
InfrastructureInput infra = new InfrastructureInput();
infra.setDevelopmentType("subsea_tieback");
infra.setTiebackDistance(25.0);  // km
workflow.setInfrastructureInput(infra);

// Run
WorkflowResult result = workflow.run();

Key Result Classes

Concept Selection (Multi-Concept Comparison)

Define Concepts

// Concept 1: Subsea tieback to existing platform
FieldConcept tieback = new FieldConcept("Subsea Tieback");
tieback.setReservoirInput(reservoir);
tieback.setWellsInput(wells);
InfrastructureInput tiebackInfra = new InfrastructureInput();
tiebackInfra.setDevelopmentType("subsea_tieback");
tiebackInfra.setTiebackDistance(25.0);
tiebackInfra.setHostCapacity(50000.0);  // boe/d
tieback.setInfrastructureInput(tiebackInfra);

// Concept 2: Standalone FPSO
FieldConcept fpso = new FieldConcept("Standalone FPSO");
fpso.setReservoirInput(reservoir);
fpso.setWellsInput(wells);
InfrastructureInput fpsoInfra = new InfrastructureInput();
fpsoInfra.setDevelopmentType("fpso");
fpso.setInfrastructureInput(fpsoInfra);

// Concept 3: Fixed platform
FieldConcept platform = new FieldConcept("Fixed Platform");
// ... configure ...

Batch Evaluation

BatchConceptRunner runner = new BatchConceptRunner();
runner.addConcept(tieback);
runner.addConcept(fpso);
runner.addConcept(platform);
runner.setFluid(tunedEosFluid);
runner.setOilPrice(70.0);    // USD/bbl
runner.setGasPrice(0.30);    // USD/Sm3
runner.setDiscountRate(0.08);

List<ConceptKPIs> results = runner.runAll();

// Rank by NPV
DevelopmentOptionRanker ranker = new DevelopmentOptionRanker();
for (ConceptKPIs kpi : results) {
    ranker.addOption(kpi);
}
List<ConceptKPIs> ranked = ranker.rankByNPV();

Physically Coupled Lifetime Comparison

Use process.fielddevelopment.lifecycle after rapid screening when reservoir pressure, well/SURF hydraulics, processing capacity, gas injection and economics must share one time-dependent state:

FieldLifecycleEvaluator evaluator = new FieldLifecycleEvaluator();
List<FieldLifecycleResult> ranked = evaluator.evaluateAll(
    NorwegianOilFieldCase.createDevelopmentPortfolio());

FieldLifecycleModel accepts a user-built ProcessSystem or a complete multi-area ProcessModel, so screening concepts can be refined without replacing the lifecycle/economic interface. Use existingSurfAndFacility(...) when the new field enters a shared existing SURF area before a host facility; wire the areas with shared streams and map host feeds at their actual subsea or topsides entry points. Whole-model execution, power, sizing and area::equipment bottlenecks then include both SURF and processing. Each concept must own an independent mutable reservoir/process model. Use FacilityLifecycleStrategy.greenfield(...) to auto-size a new detailed processing facility from design cases. Use FacilityLifecycleStrategy.tieback(...) with the existing HostFacility, ProductionProfileSeries, CapacityAllocationPolicy, and HoldbackPolicy types for a producing-host tieback. Connect the model's optional host oil/gas/water feeds to the real shared process so annual FieldLifecycleResult records host load, admitted satellite rate, deliberate holdback, capacity-deferred oil, operating and requested utilization, and their primary bottlenecks. Set FieldLifecycleModel.setProductionPotentialProvider(...) when a detailed NeqSim well/network model or imported reservoir schedule should replace the reference aggregate PI/water-cut potential calculation.

Use AreaDevelopmentPortfolio when one discovery can be routed to several independently modeled producing assets or to a new facility. Add one AreaDevelopmentOption per host/tieback route or greenfield alternative, then use AreaDevelopmentEvaluator to compare route identity, NPV, break-even, recovery, deferment, utilization, bottlenecks and specification compliance. Each option must own its reservoir, SURF and mutable process state.

Attach FieldProductSpecifications to each configuration to check live export-gas CO2/H2S/O2, ISO 6976 GCV/Wobbe, dew points, stabilized-oil RVP/BS&W and treated-water oil-in-water. The built-in evaluator uses NeqSim stream analysers and standards; connect FieldProductQualityProvider where a real facility has a dedicated water-treatment or online-analyser model. Choose REPORT_ONLY for diagnostics or REJECT_OPTION to exclude non-compliant options from the area recommendation.

For brownfield studies, preserve actual equipment limits (autoSizeDetailedProcess(false)). For greenfield studies, run the process at the simultaneous design case, auto-size equipment with the selected design margin, and use explicit oil/gas/water/liquid nameplates for non-coincident component peak cases. Put any debottleneck capacity change in capacityFromYear(...) and its CAPEX in FieldLifecycleConfiguration. Use FacilityModificationPlanner.analyse(result, targetUtilization) to create traceable screening candidates from annual requested utilization and deferred oil. Implement, size and cost each candidate in a cloned detailed process before comparing its rerun lifecycle; the planner's multiplier is not a substitute for that engineering model. See docs/fielddevelopment/FIELD_LIFECYCLE_SIMULATION.md for the connection points and fidelity boundaries.

Reservoir & Well Modeling

Material Balance (SimpleReservoir)

SimpleReservoir reservoir = new SimpleReservoir("Main Reservoir");
reservoir.setReservoirFluid(fluid.clone(), giipSm3, reservoirThickness, reservoirArea);
reservoir.addOilProducer("P1");
reservoir.addWaterInjector("I1");

// Depletion with time steps
for (int year = 0; year < 20; year++) {
    reservoir.setProductionRate(annualRate[year]);
    reservoir.run();
    pressureProfile[year] = reservoir.getReservoirPressure();
}

Inverse Material Balance / Reserves Surveillance

Regress OGIP/OOIP, drive mechanism and aquifer support directly from a measured pressure-vs-cumulative-production history (the "inverse" of the forward SimpleReservoir model). Package neqsim.pvtsimulation.reservoirproperties.materialbalance:

import neqsim.pvtsimulation.reservoirproperties.materialbalance.GasMaterialBalance;
import neqsim.pvtsimulation.reservoirproperties.materialbalance.OilMaterialBalance;
import neqsim.pvtsimulation.reservoirproperties.materialbalance.VanEverdingenHurstAquifer;

// Gas: P/Z straight line → OGIP (+ Cole plot aquifer diagnostic)
GasMaterialBalance.Result g = GasMaterialBalance.fitVolumetric(pressure, z, gp);
double ogip = g.getOgip();

// Oil: Havlena-Odeh depletion / gas-cap / water drive + Pirson drive indices
OilMaterialBalance.Result o = OilMaterialBalance.fitGasCapDrive(f, eo, eg);

// Aquifer: Van Everdingen-Hurst / Carter-Tracy cumulative influx + ECLIPSE AQUTAB
double u = VanEverdingenHurstAquifer.aquiferConstant(phi, ct, h, re, angleDeg);
double[] we = VanEverdingenHurstAquifer.cumulativeInfluxCarterTracy(tD, deltaP, u, reD);

See the neqsim-production-optimization skill for the full surveillance workflow.

Injection Strategy (Voidage Replacement)

InjectionStrategy strategy = InjectionStrategy.waterInjection(1.0);  // VRR = 1.0
InjectionResult injection = strategy.calculateInjection(
    reservoir, oilRate, gasRate, waterRate
);
double requiredInjection = injection.waterInjectionRate;  // Sm3/d

Well Performance (IPR/VLP Nodal Analysis)

WellSystem well = new WellSystem("Producer-1", reservoirStream);
well.setIPRModel(WellSystem.IPRModel.VOGEL);
well.setVogelParameters(qTest, pwfTest, pRes);
well.setTubingLength(2500.0, "m");
well.setTubingDiameter(4.0, "in");
well.setPressureDropCorrelation(
    TubingPerformance.PressureDropCorrelation.BEGGS_BRILL);
well.setWellheadPressure(50.0, "bara");
well.run();

double operatingRate = well.getOperatingFlowRate("Sm3/day");
double operatingBHP = well.getOperatingBHP("bara");

Production Network

NetworkSolver network = new NetworkSolver("Gathering System");
network.addWell(well1, 3.0);   // 3 km flowline
network.addWell(well2, 5.5);   // 5.5 km flowline
network.setSolutionMode(SolutionMode.FIXED_MANIFOLD_PRESSURE);
network.setManifoldPressure(60.0);
NetworkResult result = network.solve();

Production Forecasting

Decline Curves (Arps)

ProductionProfile profile = new ProductionProfile();
profile.setDeclineModel(ProductionProfile.DeclineModel.EXPONENTIAL);
profile.setPeakRate(25000.0);          // boe/d
profile.setDeclineRate(0.15);          // 15% per year
profile.setPlateauDuration(3);         // years
profile.setProjectLife(25);            // years
double[] annualRates = profile.generateProfile();

Decline-Curve History Matching (Arps + Duong)

Fit decline parameters to a measured rate-time history and estimate EUR with neqsim.pvtsimulation.util.DeclineCurveAnalysis (static, unit-agnostic):

import neqsim.pvtsimulation.util.DeclineCurveAnalysis;

Map<String, Double> arps = DeclineCurveAnalysis.fitArps(t, q);       // qi, di, b, rSquared
double eur = DeclineCurveAnalysis.eurFromFit(arps, qEconLimit);
Map<String, Double> duong = DeclineCurveAnalysis.fitDuong(t, q);     // q1, a, m for tight/shale wells

Production Scheduling

FieldProductionScheduler scheduler = new FieldProductionScheduler();
scheduler.setNumberOfWells(6);
scheduler.setDrillingInterval(6);      // months between wells
scheduler.setFirstOil(2027);
scheduler.setWellProductivity(5000.0); // boe/d/well
scheduler.setDeclineRate(0.12);
scheduler.setFacilityCapacity(28000.0);  // boe/d plateau constraint
double[][] schedule = scheduler.generateSchedule(25);

Well Scheduling

WellScheduler wellScheduler = new WellScheduler();
wellScheduler.setDrillingDaysPerWell(45);
wellScheduler.setCompletionDaysPerWell(25);
wellScheduler.setMobDemobDays(30);
wellScheduler.setRigs(1);
wellScheduler.setWells(6);
wellScheduler.setStartDate(2026, 1);
List<WellSchedule> schedule = wellScheduler.generate();

Facility Design Integration

Building a Process System from Concept

FacilityBuilder builder = new FacilityBuilder();
FacilityConfig config = new FacilityConfig();
config.setInletPressure(85.0);     // bara
config.setExportPressure(150.0);   // bara
config.setDesignRate(50000.0);     // boe/d

// Add processing blocks
config.addBlock(BlockType.INLET_SEPARATION, new BlockConfig()
    .set("stages", 2)
    .set("hp_pressure", 70.0)
    .set("lp_pressure", 5.0));
config.addBlock(BlockType.GAS_COMPRESSION, new BlockConfig()
    .set("stages", 3)
    .set("export_pressure", 150.0));
config.addBlock(BlockType.DEHYDRATION, new BlockConfig()
    .set("type", "TEG"));

ProcessSystem process = builder.build(config, fluid);
process.run();

Bottleneck Analysis

BottleneckAnalyzer analyzer = new BottleneckAnalyzer(process);
analyzer.setReservoirDecline(reservoir);
analyzer.setRateRange(10000, 60000, 5000);  // min, max, step (boe/d)
Map<String, Double> bottlenecks = analyzer.findBottlenecks();

Subsea Production Systems

Tieback Analysis

TiebackAnalyzer analyzer = new TiebackAnalyzer();

// Define host
HostFacility host = new HostFacility("Platform A");
host.setAvailableCapacity(30000.0);  // boe/d
host.setProcessingPressure(70.0);    // bara

// Define tieback options
TiebackOption opt1 = new TiebackOption("Direct Tieback");
opt1.setFlowlineLength(15.0);       // km
opt1.setFlowlineDiameter(10.0);     // inches
opt1.setWaterDepth(350.0);          // m

TiebackOption opt2 = new TiebackOption("Via Manifold");
opt2.setFlowlineLength(25.0);
opt2.setFlowlineDiameter(12.0);
opt2.setWaterDepth(450.0);
opt2.setHasManifold(true);
opt2.setHasBooster(true);

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

TiebackReport report = analyzer.analyze();

Subsea System Configuration

SubseaProductionSystem subsea = new SubseaProductionSystem("Subsea System");
subsea.setNumberOfWells(4);
subsea.setWaterDepth(350.0);
subsea.setFlowlineLength(25.0);
subsea.setUmbilicalLength(27.0);
subsea.setRiserType("flexible");
subsea.setTreeType("vertical");
subsea.setHasManifold(true);
subsea.setManifoldWells(4);

Key NeqSim Classes for Field Development

Common Patterns & Pitfalls

Always Verify API Before Use

NeqSim's field development classes are under active development. Before using any class, search the source to confirm:

1. The class exists and compiles
2. Constructor signatures match expected parameters
3. Methods have the expected return types

Temperature Units

• ReservoirInput.setReservoirTemperature() — Celsius (field development classes)
• SystemSrkEos(T, P) constructor — Kelvin
• Always confirm with source which convention each class uses

Production Rate Units

• NeqSim process equipment: setFlowRate(value, "kg/hr") or "Sm3/hr"
• Field development classes: typically boe/d or Sm3/d
• Always specify units explicitly

EOS Selection for Field Development

Fiscal Regime

• Norwegian NCS: 22% corporate + 56% special petroleum tax = 78% marginal rate
• UK UKCS: 30% ring-fence CT + 10% supplementary charge = 40% marginal rate
• Generic: Configurable via GenericTaxModel
• Always use CashFlowEngine with the correct country code