NeqSim Field Development Strategy

Executive Summary

This document outlines a comprehensive plan to transform NeqSim into a premier tool for field development screening, production scheduling, tie-back analysis, and new development planning. The strategy builds on existing NeqSim strengths (thermodynamics, process simulation) while adding high-level orchestration capabilities.

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Current State Analysis

Existing Building Blocks ✅

NeqSim already has substantial infrastructure for field development:

Package	Class	Purpose	Maturity
process.equipment.reservoir	SimpleReservoir	Tank-type material balance model	✅ Stable
process.equipment.reservoir	WellFlow	IPR (inflow performance) modeling	✅ Stable
process.equipment.reservoir	WellSystem	Combined IPR + VLP (tubing) model	✅ Stable
process.equipment.reservoir	TubingPerformance	Vertical lift performance	✅ Stable
process.fielddevelopment.concept	FieldConcept	High-level concept definition	✅ New
process.fielddevelopment.concept	ReservoirInput	Reservoir characterization	✅ New
process.fielddevelopment.concept	WellsInput	Well configuration	✅ New
process.fielddevelopment.concept	InfrastructureInput	Infrastructure definition	✅ New
process.fielddevelopment.screening	FlowAssuranceScreener	Hydrate/wax/corrosion screening	✅ New
process.fielddevelopment.screening	EconomicsEstimator	CAPEX/OPEX estimation	✅ New
process.fielddevelopment.screening	SafetyScreener	Safety screening	✅ New
process.fielddevelopment.screening	EmissionsTracker	CO2 emissions estimation	✅ New
process.fielddevelopment.evaluation	ConceptEvaluator	Concept orchestration	✅ New
process.fielddevelopment.evaluation	BatchConceptRunner	Multi-concept comparison	✅ New
process.fielddevelopment.facility	FacilityBuilder	Modular facility configuration	✅ New
process.util.fielddevelopment	ProductionProfile	Decline curve modeling	✅ Stable
process.util.fielddevelopment	WellScheduler	Well intervention scheduling	✅ Stable
process.util.fielddevelopment	FacilityCapacity	Bottleneck analysis	✅ Stable
process.util.fielddevelopment	SensitivityAnalysis	Monte Carlo analysis	✅ Stable
process.util.fielddevelopment	FieldProductionScheduler	Production scheduling	🔄 New (basic)
process.util.optimization	ProductionOptimizer	Production optimization	✅ Stable

Gaps Identified 🔴

1. Tie-back Analysis Engine - No dedicated tie-back screening tool
2. Multi-Field Portfolio - No portfolio optimization across fields
3. Norwegian Petroleum Economics - No tax model (22% corp + 56% special)
4. Facilities Integration - Limited connection between concept and process
5. Time-Series Export - No E300/ECLIPSE integration for reservoir coupling
6. Decision Support - No ranking/scoring for development options
7. Pipeline Hydraulics Integration - Loose coupling with multiphase flow

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Strategic Architecture

Proposed Module Structure

neqsim.process.fielddevelopment
├── concept/                     # EXISTING - Concept definition
│   ├── FieldConcept.java
│   ├── ReservoirInput.java
│   ├── WellsInput.java
│   └── InfrastructureInput.java
│
├── evaluation/                  # EXISTING - Concept evaluation
│   ├── ConceptEvaluator.java
│   ├── ConceptKPIs.java
│   └── BatchConceptRunner.java
│
├── screening/                   # EXISTING - Screening tools
│   ├── FlowAssuranceScreener.java
│   ├── EconomicsEstimator.java
│   ├── SafetyScreener.java
│   └── EmissionsTracker.java
│
├── facility/                    # EXISTING - Facility blocks
│   ├── FacilityBuilder.java
│   ├── FacilityConfig.java
│   ├── BlockType.java
│   └── BlockConfig.java
│
├── tieback/                     # NEW - Tie-back analysis
│   ├── TiebackAnalyzer.java
│   ├── TiebackOption.java
│   ├── TiebackReport.java
│   └── HostFacility.java
│
├── portfolio/                   # NEW - Multi-field portfolio
│   ├── PortfolioOptimizer.java
│   ├── FieldAsset.java
│   ├── InvestmentSchedule.java
│   └── PortfolioReport.java
│
├── economics/                   # NEW - Advanced economics
│   ├── NorwegianTaxModel.java
│   ├── CashFlowEngine.java
│   ├── NPVCalculator.java
│   ├── BreakevenAnalyzer.java
│   └── TariffModel.java
│
└── scheduling/                  # NEW - Production scheduling
    ├── FieldScheduler.java
    ├── ProductionForecast.java
    ├── DrillSchedule.java
    └── FacilitiesSchedule.java

Proposed Utility Location

neqsim.process.util.fielddevelopment
├── ProductionProfile.java       # EXISTING
├── WellScheduler.java           # EXISTING
├── FacilityCapacity.java        # EXISTING
├── SensitivityAnalysis.java     # EXISTING
├── FieldProductionScheduler.java # EXISTING - Enhance
└── PipelineNetwork.java         # NEW - Multi-segment pipeline

---

Implementation Plan

Phase 1: Core Economics (Priority: HIGH) 🎯

Goal: Enable accurate NPV and decision-support calculations

1.1 Norwegian Petroleum Tax Model

package neqsim.process.fielddevelopment.economics;

/**
 * Norwegian Continental Shelf petroleum tax model.
 * 
 * Implements:
 * - 22% corporate tax
 * - 56% special petroleum tax  
 * - Uplift deductions
 * - Loss carry-forward
 */
public class NorwegianTaxModel {
    private static final double CORPORATE_TAX_RATE = 0.22;
    private static final double PETROLEUM_TAX_RATE = 0.56;
    private static final double TOTAL_MARGINAL_RATE = 0.78;
    
    private double upliftRate = 0.055; // 5.5% per year for 4 years
    private int upliftYears = 4;
    
    public TaxResult calculateTax(double grossRevenue, double opex, 
                                   double depreciation, double uplift) {
        // Corporate tax base
        double corporateTaxBase = grossRevenue - opex - depreciation;
        double corporateTax = Math.max(0, corporateTaxBase * CORPORATE_TAX_RATE);
        
        // Special petroleum tax base (with uplift)
        double specialTaxBase = grossRevenue - opex - depreciation - uplift;
        double specialTax = Math.max(0, specialTaxBase * PETROLEUM_TAX_RATE);
        
        return new TaxResult(corporateTax, specialTax, 
                            corporateTax + specialTax);
    }
}

1.2 Cash Flow Engine

package neqsim.process.fielddevelopment.economics;

/**
 * Full-lifecycle cash flow engine for field development.
 */
public class CashFlowEngine {
    private NorwegianTaxModel taxModel;
    private TariffModel tariffModel;
    
    public CashFlowResult generateCashFlow(
        ProductionForecast production,
        CapexSchedule capex,
        OpexProfile opex,
        PriceScenario prices,
        int forecastYears
    ) {
        // Year-by-year cash flow with tax
    }
    
    public double calculateNPV(CashFlowResult cashFlow, double discountRate);
    public double calculateIRR(CashFlowResult cashFlow);
    public double calculateBreakevenPrice(CashFlowResult cashFlow, 
                                          double targetNPV);
    public double calculatePaybackPeriod(CashFlowResult cashFlow);
}

Phase 2: Tie-back Analysis Engine (Priority: HIGH) 🎯

Goal: Screen and compare tie-back options to existing infrastructure

2.1 Tie-back Analyzer

package neqsim.process.fielddevelopment.tieback;

/**
 * Analyzes tie-back options for marginal field development.
 * 
 * Considers:
 * - Distance to host
 * - Host spare capacity (gas, oil, water handling)
 * - Pipeline hydraulics (pressure drop, flow assurance)
 * - Cost comparison
 */
public class TiebackAnalyzer {
    
    public TiebackReport analyze(FieldConcept discovery, 
                                  List<HostFacility> hosts) {
        List<TiebackOption> options = new ArrayList<>();
        
        for (HostFacility host : hosts) {
            TiebackOption option = evaluateTieback(discovery, host);
            if (option.isFeasible()) {
                options.add(option);
            }
        }
        
        // Rank by NPV
        options.sort(Comparator.comparing(TiebackOption::getNpv).reversed());
        
        return new TiebackReport(discovery, options);
    }
    
    private TiebackOption evaluateTieback(FieldConcept discovery, 
                                           HostFacility host) {
        // 1. Check distance and water depth
        // 2. Screen flow assurance (hydrate, wax in flowline)
        // 3. Check host capacity constraints
        // 4. Estimate CAPEX (pipeline, umbilical, subsea)
        // 5. Calculate production profile (constrained by host)
        // 6. Calculate NPV
    }
}

2.2 Host Facility Model

package neqsim.process.fielddevelopment.tieback;

/**
 * Represents an existing host facility with spare capacity.
 */
public class HostFacility {
    private String name;
    private double latitude;
    private double longitude;
    private double waterDepth;
    
    // Capacity constraints
    private double gasCapacityMSm3d;
    private double oilCapacityBopd;
    private double waterCapacityM3d;
    private double liquidCapacityM3d;
    
    // Current utilization
    private double gasUtilization;
    private double oilUtilization;
    private double waterUtilization;
    
    // Tie-in points
    private double minTieInPressureBara;
    private double maxTieInPressureBara;
    
    // Associated process system (optional)
    private ProcessSystem facility;
    
    public double getSpareGasCapacity() {
        return gasCapacityMSm3d * (1.0 - gasUtilization);
    }
    
    public boolean canAccept(FieldConcept discovery) {
        // Check if host has capacity for new tieback
    }
}

Phase 3: Enhanced FieldProductionScheduler (Priority: HIGH) 🎯

Goal: Transform into full-featured production scheduler

3.1 Enhance Existing FieldProductionScheduler

Add to FieldProductionScheduler.java:

// Norwegian Tax Integration
private NorwegianTaxModel taxModel = new NorwegianTaxModel();
private TariffModel tariffModel;
private double corporateTaxRate = 0.22;
private double petroleumTaxRate = 0.56;

// Enhanced Economics
public void setTariffModel(TariffModel tariff);
public void setTaxModel(NorwegianTaxModel taxModel);
public double calculateAfterTaxNPV(double discountRate);
public double calculateBreakevenOilPrice();
public double calculateBreakevenGasPrice();

// Transient Sub-stepping (from notebook patterns)
public void setTransientSubSteps(int subSteps); // e.g., 10 per time step
private void runReservoirTransient(double timestepDays, int subSteps);

// Pipeline Pressure Constraints
public void setPipelinePressureConstraint(double minPressureBara);
public void useAdjusterForRateOptimization(boolean enable);

// Drilling Schedule Integration
public void setDrillSchedule(DrillSchedule schedule);
public void addWellOnlineDate(String wellName, LocalDate date);

// Enhanced Reporting
public CashFlowResult getCashFlow();
public Map<String, Double> getSensitivityToOilPrice(double[] prices);
public String exportToExcel();

Phase 4: Portfolio Optimization (Priority: MEDIUM)

Goal: Optimize investment across multiple fields/opportunities

4.1 Portfolio Optimizer

package neqsim.process.fielddevelopment.portfolio;

/**
 * Optimizes capital allocation across a portfolio of opportunities.
 * 
 * Considers:
 * - Capital budget constraints
 * - Risk diversification
 * - Synergies (shared infrastructure)
 * - Phasing and timing
 */
public class PortfolioOptimizer {
    private List<FieldAsset> assets;
    private double annualCapexBudget;
    private double maxPortfolioRisk;
    
    public InvestmentSchedule optimize(int planningHorizon) {
        // Mixed-integer programming for optimal phasing
    }
    
    public PortfolioReport analyze() {
        // Risk-return analysis
        // Efficient frontier
        // Sensitivity analysis
    }
}

Phase 5: Pipeline Network (Priority: MEDIUM)

Goal: Multi-segment pipeline network for complex tie-backs

package neqsim.process.util.fielddevelopment;

/**
 * Multi-segment pipeline network for tie-back analysis.
 */
public class PipelineNetwork {
    private List<PipelineSegment> segments;
    private List<Node> nodes;
    
    public void addSegment(String from, String to, 
                           double lengthKm, double diameterInches,
                           double roughness, boolean insulated);
    
    public void addNode(String name, NodeType type);
    
    public NetworkResult solve(Map<String, Double> sourceRates,
                               Map<String, Double> sinkPressures);
    
    public FlowAssuranceReport screenFlowAssurance(double seabedTempC);
}

---

Use Case Workflows

Use Case 1: Gas Tie-back Screening

// 1. Define discovery
FieldConcept discovery = FieldConcept.builder("Marginal Gas Discovery")
    .reservoir(ReservoirInput.leanGas()
        .gor(15000)
        .co2Percent(2.5)
        .reservoirPressure(350)
        .reservoirTemperature(95)
        .build())
    .wells(WellsInput.builder()
        .producerCount(2)
        .tubeheadPressure(120)
        .ratePerWell(0.8e6, "Sm3/d")
        .build())
    .build();

// 2. Define potential hosts
List<HostFacility> hosts = Arrays.asList(
    HostFacility.builder("Platform A")
        .location(61.5, 2.3)
        .waterDepth(110)
        .spareGasCapacity(3.0, "MSm3/d")
        .minTieInPressure(80)
        .build(),
    HostFacility.builder("FPSO B")
        .location(61.8, 2.1)
        .waterDepth(350)
        .spareGasCapacity(5.0, "MSm3/d")
        .build()
);

// 3. Analyze options
TiebackAnalyzer analyzer = new TiebackAnalyzer();
TiebackReport report = analyzer.analyze(discovery, hosts);

// 4. Review results
System.out.println(report.getSummary());
TiebackOption best = report.getBestOption();
System.out.println("Best option: " + best.getHostName() + 
                   ", NPV: " + best.getNpvMUSD() + " MUSD");

Use Case 2: Field Development with NPV

// 1. Create reservoir model
SystemInterface gasFluid = new SystemSrkEos(273.15 + 90, 300);
gasFluid.addComponent("methane", 0.85);
gasFluid.addComponent("ethane", 0.08);
gasFluid.addComponent("propane", 0.04);
gasFluid.addComponent("CO2", 0.03);
gasFluid.setMixingRule("classic");

SimpleReservoir reservoir = new SimpleReservoir("Gas Field");
reservoir.setReservoirFluid(gasFluid, 5.0e9, 1.0, 1.0e8);
reservoir.addGasProducer("GP-1");
reservoir.addGasProducer("GP-2");

// 2. Create scheduler with economics
FieldProductionScheduler scheduler = new FieldProductionScheduler("Offshore Gas");
scheduler.addReservoir(reservoir);

// 3. Set production parameters
scheduler.setPlateauRate(10.0, "MSm3/day");
scheduler.setPlateauDuration(5, "years");
scheduler.setMinimumRate(1.0, "MSm3/day");

// 4. Set economics
scheduler.setGasPrice(0.25, "USD/Sm3");
scheduler.setDiscountRate(0.08);
scheduler.setCapex(800, "MUSD");
scheduler.setOpexRate(0.04); // 4% of CAPEX per year
scheduler.setTaxModel(new NorwegianTaxModel());

// 5. Generate schedule
ProductionSchedule schedule = scheduler.generateSchedule(
    LocalDate.of(2026, 1, 1), 
    20.0,  // years
    365.0  // annual steps
);

// 6. Results
System.out.println("Cumulative Gas: " + schedule.getCumulativeGas("GSm3") + " GSm3");
System.out.println("Pre-tax NPV: " + schedule.getPreTaxNPV("MUSD") + " MUSD");
System.out.println("After-tax NPV: " + schedule.getAfterTaxNPV("MUSD") + " MUSD");
System.out.println("Breakeven gas price: " + 
    scheduler.calculateBreakevenGasPrice() + " USD/Sm3");

Use Case 3: Portfolio Investment Planning

// 1. Define portfolio
PortfolioOptimizer optimizer = new PortfolioOptimizer();

optimizer.addAsset(FieldAsset.builder("Gas Field A")
    .npv(500)
    .capex(800)
    .firstProduction(2026)
    .reserves(15, "GSm3")
    .build());

optimizer.addAsset(FieldAsset.builder("Oil Development B")
    .npv(300)
    .capex(1200)
    .firstProduction(2027)
    .reserves(50, "MMbbl")
    .build());

optimizer.addAsset(FieldAsset.builder("Tieback C")
    .npv(150)
    .capex(200)
    .firstProduction(2025)
    .reserves(3, "GSm3")
    .build());

// 2. Set constraints
optimizer.setAnnualCapexBudget(500, "MUSD");
optimizer.setPlanningHorizon(10); // years

// 3. Optimize
InvestmentSchedule schedule = optimizer.optimize();

// 4. Results
System.out.println(schedule.getGanttChart());
System.out.println("Portfolio NPV: " + schedule.getTotalNPV());
System.out.println("Capital efficiency: " + schedule.getCapitalEfficiency());

---

Integration Points

With Existing NeqSim

Component	Integration
SystemInterface	Fluid PVT for reservoir/flow assurance
SimpleReservoir	Material balance depletion
WellFlow / WellSystem	IPR/VLP for well modeling
ProcessSystem	Facility simulation
AdiabaticTwoPhasePipe	Pipeline hydraulics
Adjuster	Rate optimization to constraints

With External Tools

Tool	Integration Method
ECLIPSE/E300	Export SCHEDULE section
Excel	Export time series / reports
Python/Jupyter	neqsim-python bindings
Power BI	CSV/JSON export
Spotfire	Data export APIs

---

Testing Strategy

Unit Tests

src/test/java/neqsim/process/fielddevelopment/
├── economics/
│   ├── NorwegianTaxModelTest.java
│   ├── CashFlowEngineTest.java
│   └── NPVCalculatorTest.java
├── tieback/
│   ├── TiebackAnalyzerTest.java
│   └── HostFacilityTest.java
├── portfolio/
│   └── PortfolioOptimizerTest.java
└── scheduling/
    └── FieldSchedulerTest.java

Integration Tests

• Volve field case study (public data)
• Synthetic gas tie-back scenarios
• Multi-reservoir commingled production

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Implementation Priority

Phase	Component	Priority	Effort	Value
1.1	NorwegianTaxModel	HIGH	2 days	HIGH
1.2	CashFlowEngine	HIGH	3 days	HIGH
2.1	TiebackAnalyzer	HIGH	5 days	VERY HIGH
2.2	HostFacility	HIGH	2 days	HIGH
3.1	FieldProductionScheduler enhancements	HIGH	3 days	HIGH
4.1	PortfolioOptimizer	MEDIUM	5 days	MEDIUM
5.1	PipelineNetwork	MEDIUM	4 days	MEDIUM

---

Success Metrics

1. Screening Speed: Evaluate tie-back option in < 5 seconds
2. Accuracy: NPV within ±20% of detailed engineering
3. Usability: Simple API for common workflows
4. Integration: Seamless connection to existing NeqSim
5. Documentation: Complete JavaDoc and examples

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Next Steps

1. Immediate: Implement NorwegianTaxModel and CashFlowEngine
2. Week 1: Enhance FieldProductionScheduler with tax integration
3. Week 2: Implement TiebackAnalyzer and HostFacility
4. Week 3: Create integration tests with Volve data
5. Week 4: Portfolio optimizer (if time permits)

---

Appendix: Norwegian Petroleum Economics Reference

Tax Rates (2024)

• Corporate tax: 22%
• Special petroleum tax: 56%
• Total marginal rate: 78%

Deductions

• Depreciation: Straight-line over 6 years
• Uplift: 5.5% per year for 4 years (22% total)
• Exploration costs: 100% deductible

Tariffs (Typical)

• Gas transport (Gassled): 0.10-0.15 NOK/Sm³
• Oil transport: Varies by system

Price Assumptions (Planning)

• Oil: 70-80 USD/bbl
• Gas: 0.20-0.30 USD/Sm³
• Exchange rate: 10 NOK/USD