Stream Fitters: GOR and MPFM Data Fitting

Utilities for adjusting stream compositions based on measured Gas-Oil Ratio (GOR) or Multiphase Flow Meter (MPFM) data.

Overview
GORfitter
MPFMfitter
API Reference
Best Practices
Python Examples

Overview

Stream fitters are utility process equipment that adjust the composition of a hydrocarbon stream to match measured field data. They are essential for:

Production Allocation: Matching model predictions to actual measurements
Digital Twin Synchronization: Keeping simulation aligned with real operations
Virtual Flow Metering: Calibrating VFM models to test separator data
Well Test Analysis: Adjusting simulated GOR to match test separator results

Class	Purpose	Key Measurement
`GORfitter`	Adjust stream to match measured GOR	Gas-Oil Ratio (Sm³/Sm³ or GVF)
`MPFMfitter`	Adjust stream based on MPFM readings	GOR + reference fluid package

Location: neqsim.process.equipment.util

GORfitter

Description

The GORfitter class adjusts a hydrocarbon stream’s gas content to achieve a specified Gas-Oil Ratio at standard or actual conditions. It modifies the gas phase composition while preserving the total mass flow rate.

                       ┌─────────────┐
   Inlet Stream ──────▶│  GORfitter  │──────▶ Adjusted Stream
   (Original GOR)      │             │        (Target GOR)
                       │ Target GOR: │
                       │   120 Sm³/Sm³│
                       └─────────────┘

How It Works

Flash at Reference Conditions: The inlet stream is flashed at standard conditions (15°C, 1.01325 bara) or actual conditions
Calculate Current GOR: Measure gas volume / oil volume at reference conditions
Calculate Deviation: Determine factor to adjust gas content: dev = targetGOR / currentGOR
Adjust Composition: Scale gas-phase component moles by the deviation factor
Re-flash at Original Conditions: Return stream to original P/T with new composition

Usage Examples

Basic GOR Adjustment

import neqsim.process.equipment.stream.Stream;
import neqsim.process.equipment.util.GORfitter;
import neqsim.thermo.system.SystemSrkEos;

// Create a reservoir fluid
SystemSrkEos fluid = new SystemSrkEos(340.0, 150.0);
fluid.addComponent("methane", 0.40);
fluid.addComponent("ethane", 0.05);
fluid.addComponent("propane", 0.03);
fluid.addComponent("nC10", 0.30);
fluid.addComponent("nC20", 0.22);
fluid.setMixingRule("classic");

// Create inlet stream
Stream wellStream = new Stream("Well-A", fluid);
wellStream.setFlowRate(1000.0, "kg/hr");
wellStream.run();

// Adjust to measured GOR
GORfitter gorFitter = new GORfitter("GOR Adjuster", wellStream);
gorFitter.setGOR(150.0);  // Target GOR: 150 Sm³/Sm³
gorFitter.run();

// Get adjusted stream
double adjustedGOR = gorFitter.getOutletStream()
    .getFluid().getGOR("Sm3/Sm3");
System.out.println("Adjusted GOR: " + adjustedGOR + " Sm³/Sm³");

Using Gas Volume Fraction (GVF)

// Fit using GVF instead of GOR
GORfitter gvfFitter = new GORfitter("GVF Adjuster", wellStream);
gvfFitter.setFitAsGVF(true);  // Enable GVF mode
gvfFitter.setGOR(0.35);       // Target GVF: 35%
gvfFitter.run();

double resultGVF = gvfFitter.getGFV();
System.out.println("Adjusted GVF: " + (resultGVF * 100) + "%");

Custom Reference Conditions

// Use actual conditions instead of standard
GORfitter actualFitter = new GORfitter("Actual Conditions", wellStream);
actualFitter.setGOR(120.0);
actualFitter.setReferenceConditions("actual");  // Use actual P/T
actualFitter.run();

Configuration

Parameter	Method	Description	Default
Target GOR	`setGOR(double)`	Gas-Oil Ratio in Sm³/Sm³	120.0
Reference Conditions	`setReferenceConditions(String)`	“standard” or “actual”	“standard”
GVF Mode	`setFitAsGVF(boolean)`	Treat GOR value as GVF fraction	false
Reference P	`setPressure(double, String)`	Reference pressure	1.01325 bara
Reference T	`setTemperature(double, String)`	Reference temperature	15°C

MPFMfitter

MPFMfitter Description

The MPFMfitter extends GOR fitting capabilities with support for a reference fluid package, enabling more accurate matching with Multiphase Flow Meter readings.

Reference Fluid Package

The MPFM fitter can use a separate “reference” thermodynamic system for GOR calculations while preserving the original fluid package for downstream simulation:

import neqsim.process.equipment.util.MPFMfitter;

// Create main fluid
SystemSrkCPAstatoil processFluid = new SystemSrkCPAstatoil(340.0, 150.0);
// ... add components

// Create reference fluid for MPFM calculations
SystemSrkEos referenceFluid = new SystemSrkEos(288.15, 1.01325);
referenceFluid.addComponent("methane", 0.85);
referenceFluid.addComponent("ethane", 0.08);
referenceFluid.addComponent("propane", 0.04);
referenceFluid.addComponent("nC6", 0.03);
referenceFluid.setMixingRule("classic");

// Set up MPFM fitter
MPFMfitter mpfm = new MPFMfitter("MPFM-101", processStream);
mpfm.setReferenceFluidPackage(referenceFluid);
mpfm.setGOR(145.0);  // MPFM-measured GOR
mpfm.run();

MPFM Usage Examples

Complete Well Test Analysis

import neqsim.process.processmodel.ProcessSystem;
import neqsim.process.equipment.stream.Stream;
import neqsim.process.equipment.util.MPFMfitter;
import neqsim.process.equipment.separator.Separator;

// Build process
ProcessSystem process = new ProcessSystem("Well Test");

// Well stream (from reservoir model or initial guess)
Stream wellStream = new Stream("Well-A", reservoirFluid);
wellStream.setFlowRate(5000.0, "kg/hr");
process.add(wellStream);

// MPFM adjustment based on field measurement
MPFMfitter mpfm = new MPFMfitter("MPFM-201", wellStream);
mpfm.setGOR(125.0);  // From MPFM reading
mpfm.setReferenceConditions("standard");
process.add(mpfm);

// Test separator
Separator testSep = new Separator("Test Separator", mpfm.getOutletStream());
testSep.setInternalDiameter(1.2);
process.add(testSep);

// Run analysis
process.run();

// Verify results match MPFM
double measuredGOR = mpfm.getGOR();
double separatorGOR = testSep.getGasOutStream().getFluid().getGOR("Sm3/Sm3");
System.out.println("MPFM GOR: " + measuredGOR);
System.out.println("Separator GOR: " + separatorGOR);

API Reference

GORfitter

Method	Return Type	Description
`GORfitter(String, StreamInterface)`	-	Constructor
`setGOR(double)`	void	Set target GOR (Sm³/Sm³ or GVF if fitAsGVF)
`getGOR()`	double	Get current GOR setting
`setFitAsGVF(boolean)`	void	Treat GOR as GVF fraction
`getFitAsGVF()`	boolean	Check if fitting as GVF
`getGFV()`	double	Get resulting GVF after fitting
`setReferenceConditions(String)`	void	“standard” or “actual”
`getReferenceConditions()`	String	Get current reference setting
`setPressure(double, String)`	void	Set reference pressure
`setTemperature(double, String)`	void	Set reference temperature
`run()`	void	Execute fitting calculation

MPFMfitter

Inherits all GORfitter methods plus:

Method	Return Type	Description
`setReferenceFluidPackage(SystemInterface)`	void	Set reference fluid for GOR calc
`getReferenceFluidPackage()`	SystemInterface	Get reference fluid

Best Practices

1. Reference Conditions Consistency

Ensure reference conditions match how GOR was measured:

// For standard conditions (most common)
gorFitter.setReferenceConditions("standard");
gorFitter.setTemperature(15.0, "C");          // SC temperature
gorFitter.setPressure(1.01325, "bara");       // SC pressure

// For actual conditions (downhole MPFM)
gorFitter.setReferenceConditions("actual");

2. GVF vs GOR

Choose the appropriate mode based on your measurement:

// GOR mode: Gas/Oil volume ratio (Sm³/Sm³)
gorFitter.setFitAsGVF(false);
gorFitter.setGOR(150.0);  // 150 Sm³ gas per Sm³ oil

// GVF mode: Gas volume fraction (0-1)  
gorFitter.setFitAsGVF(true);
gorFitter.setGOR(0.40);   // 40% gas by volume

3. Handling Edge Cases

// Zero GOR (dead oil)
gorFitter.setGOR(0.0);  // Removes all gas

// Very high GOR (gas condensate)
gorFitter.setGOR(5000.0);  // High gas content

// Check for valid output
if (!Double.isNaN(gorFitter.getGFV())) {
    // Valid result
} else {
    // Handle invalid result
}

Python Examples

Basic GOR Fitting (Python)

from neqsim.process.equipment.util import GORfitter
from neqsim.process.equipment.stream import Stream
from neqsim.thermo.system import SystemSrkEos

# Create fluid
fluid = SystemSrkEos(340.0, 150.0)
fluid.addComponent("methane", 0.35)
fluid.addComponent("ethane", 0.05)
fluid.addComponent("nC10", 0.40)
fluid.addComponent("nC20", 0.20)
fluid.setMixingRule("classic")

# Create stream
well = Stream("Well-1", fluid)
well.setFlowRate(2000.0, "kg/hr")
well.run()

# Apply GOR fitting
gor_fitter = GORfitter("GOR-Fitter", well)
gor_fitter.setGOR(125.0)  # Target GOR from well test
gor_fitter.run()

# Check result
fitted_stream = gor_fitter.getOutletStream()
print(f"Fitted GOR: {fitted_stream.getFluid().getGOR('Sm3/Sm3'):.1f} Sm³/Sm³")
print(f"GVF: {gor_fitter.getGFV() * 100:.1f}%")

GVF Mode (Python)

# Use GVF mode for volume fraction
gvf_fitter = GORfitter("GVF-Fitter", well)
gvf_fitter.setFitAsGVF(True)
gvf_fitter.setGOR(0.30)  # Target 30% GVF
gvf_fitter.run()

print(f"Result GVF: {gvf_fitter.getGFV() * 100:.1f}%")

Well Allocation - Production allocation methods
Streams - Stream creation and manipulation
Separators - Test separator modeling
Digital Twin Integration - Real-time calibration

Package Location: neqsim.process.equipment.util

Stream Fitters: GOR and MPFM Data Fitting

Comprehensive Java library for thermodynamic, physical property, and process simulation. NeqSim provides tools for PVT analysis, phase equilibria, transport properties, and full process simulation.

Stream Fitters: GOR and MPFM Data Fitting

Table of Contents

Overview

GORfitter

Description

How It Works

Usage Examples

Basic GOR Adjustment

Using Gas Volume Fraction (GVF)

Custom Reference Conditions

Configuration

MPFMfitter

MPFMfitter Description

Reference Fluid Package

MPFM Usage Examples

Complete Well Test Analysis

API Reference

GORfitter

MPFMfitter

Best Practices

1. Reference Conditions Consistency

2. GVF vs GOR

3. Handling Edge Cases

Python Examples

Basic GOR Fitting (Python)

GVF Mode (Python)

Stream Fitters: GOR and MPFM Data Fitting

Table of Contents

Overview

GORfitter

Description

How It Works

Usage Examples

Basic GOR Adjustment

Using Gas Volume Fraction (GVF)

Custom Reference Conditions

Configuration

MPFMfitter

MPFMfitter Description

Reference Fluid Package

MPFM Usage Examples

Complete Well Test Analysis

API Reference

GORfitter

MPFMfitter

Best Practices

1. Reference Conditions Consistency

2. GVF vs GOR

3. Handling Edge Cases

Python Examples

Basic GOR Fitting (Python)

GVF Mode (Python)

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