Subsea Boosters

Documentation for subsea booster pump and compressor equipment in NeqSim.

Table of Contents

Overview

Location: neqsim.process.equipment.subsea

A subsea booster is a pump or compressor installed on the seabed to enhance production from subsea wells. The SubseaBooster class models:

Class Description
SubseaBooster Subsea pump/compressor unit
SubseaBoosterMechanicalDesign Mechanical design calculations

SubseaBooster Class

Class Hierarchy

TwoPortEquipment
└── SubseaBooster
    ├── enum: BoosterType
    ├── enum: PumpType
    └── contains: Compressor or Pump

Key Features

Constructor

import neqsim.process.equipment.subsea.SubseaBooster;

// Create subsea booster
SubseaBooster booster = new SubseaBooster("Subsea Booster", wellStream);
booster.setBoosterType(SubseaBooster.BoosterType.MULTIPHASE_PUMP);
booster.setPumpType(SubseaBooster.PumpType.HELICO_AXIAL);
booster.setWaterDepth(450.0);
booster.setOutletPressure(150.0);

Booster Types

BoosterType Enumeration

Type Description Application
MULTIPHASE_PUMP Handles gas-liquid mixture Standard production
LIQUID_PUMP Single-phase liquid only After separation
WET_GAS_COMPRESSOR Compressor with liquid tolerance High GVF streams
DRY_GAS_COMPRESSOR Compressor after separation Subsea separation
SEPARATOR_BOOSTER Combined separator + booster Complex systems

Selecting Booster Type

// Multiphase pump for well stream
booster.setBoosterType(SubseaBooster.BoosterType.MULTIPHASE_PUMP);

// Liquid pump after subsea separator
booster.setBoosterType(SubseaBooster.BoosterType.LIQUID_PUMP);

// Wet gas compressor for high GVF
booster.setBoosterType(SubseaBooster.BoosterType.WET_GAS_COMPRESSOR);

Booster Type Selection Guide

Stream GVF Water Cut Recommended Type
0-50% Any MULTIPHASE_PUMP
50-90% <30% MULTIPHASE_PUMP
50-90% >30% WET_GAS_COMPRESSOR
>90% <5% WET_GAS_COMPRESSOR
100% gas 0% DRY_GAS_COMPRESSOR
0% gas Any LIQUID_PUMP

Pump Types

PumpType Enumeration

Type Description Max GVF ΔP Range
HELICO_AXIAL Helico-axial multiphase 95% 50-150 bar
TWIN_SCREW Twin-screw positive displacement 100% 20-80 bar
COUNTER_ROTATING_AXIAL Counter-rotating design 95% 80-200 bar
ESP Electrical submersible pump 20% 100-300 bar
CENTRIFUGAL_SINGLE Single-stage centrifugal 10% 10-30 bar
CENTRIFUGAL_MULTI Multi-stage centrifugal 10% 50-200 bar

Selecting Pump Type

// Helico-axial for moderate GVF
booster.setPumpType(SubseaBooster.PumpType.HELICO_AXIAL);

// Twin-screw for high GVF or slugging
booster.setPumpType(SubseaBooster.PumpType.TWIN_SCREW);

// ESP for low GVF, high head
booster.setPumpType(SubseaBooster.PumpType.ESP);

Performance Modeling

Setting Operating Point

// Set target outlet pressure
booster.setOutletPressure(180.0);  // bara

// Or set differential pressure
booster.setDifferentialPressure(80.0);  // bar

// Set speed (% of rated)
booster.setSpeed(95.0);  // 95% speed

Power and Efficiency

// Set power rating
booster.setPowerRatingMW(5.0);  // 5 MW motor

// Set efficiency
booster.setEfficiency(0.75);  // 75% hydraulic efficiency

// After running
booster.run();

// Get actual power consumption
double power = booster.getPower("MW");
System.out.println("Power consumption: " + power + " MW");

Performance Curves

// Set performance curve (flow vs head)
double[] flows = {0, 500, 1000, 1500, 2000};  // m³/hr
double[] heads = {200, 195, 180, 155, 120};   // m

booster.setPerformanceCurve(flows, heads);

// Set efficiency curve
double[] efficiencies = {0, 0.65, 0.75, 0.72, 0.60};
booster.setEfficiencyCurve(flows, efficiencies);

Usage Examples

Example 1: Multiphase Pump for Production Boosting

import neqsim.thermo.system.SystemSrkEos;
import neqsim.process.equipment.stream.Stream;
import neqsim.process.equipment.subsea.SubseaBooster;

// Create well fluid
SystemSrkEos fluid = new SystemSrkEos(353.15, 100.0);
fluid.addComponent("methane", 60.0);
fluid.addComponent("ethane", 8.0);
fluid.addComponent("propane", 5.0);
fluid.addComponent("n-heptane", 25.0);
fluid.addComponent("water", 2.0);
fluid.setMixingRule("classic");

// Create manifold outlet stream
Stream manifoldStream = new Stream("Manifold Outlet", fluid);
manifoldStream.setFlowRate(80000.0, "kg/hr");
manifoldStream.setTemperature(60.0, "C");
manifoldStream.setPressure(80.0, "bara");
manifoldStream.run();

// Create multiphase booster
SubseaBooster booster = new SubseaBooster("Subsea Booster", manifoldStream);
booster.setBoosterType(SubseaBooster.BoosterType.MULTIPHASE_PUMP);
booster.setPumpType(SubseaBooster.PumpType.HELICO_AXIAL);
booster.setWaterDepth(500.0);
booster.setOutletPressure(150.0);  // Boost to 150 bara
booster.setPowerRatingMW(4.0);
booster.setEfficiency(0.72);

// Run booster
booster.run();

// Results
System.out.println("Inlet pressure: " + manifoldStream.getPressure() + " bara");
System.out.println("Outlet pressure: " + booster.getOutletStream().getPressure() + " bara");
System.out.println("Power: " + booster.getPower("MW") + " MW");
System.out.println("ΔP: " + booster.getDifferentialPressure() + " bar");

Example 2: Long-Distance Tieback with Boosting

import neqsim.process.equipment.pipeline.AdiabaticPipe;

// Well stream at remote location
Stream wellStream = new Stream("Remote Well", fluid);
wellStream.setFlowRate(30000.0, "kg/hr");
wellStream.setPressure(120.0, "bara");
wellStream.run();

// First pipeline segment (25 km to booster)
AdiabaticPipe pipe1 = new AdiabaticPipe("Flowline 1", wellStream);
pipe1.setLength(25000.0);
pipe1.setDiameter(0.254);  // 10"
pipe1.run();

System.out.println("Pressure at booster inlet: " + pipe1.getOutletPressure() + " bara");

// Subsea booster station
SubseaBooster booster = new SubseaBooster("Mid-Line Booster", pipe1.getOutletStream());
booster.setBoosterType(SubseaBooster.BoosterType.MULTIPHASE_PUMP);
booster.setPumpType(SubseaBooster.PumpType.HELICO_AXIAL);
booster.setOutletPressure(150.0);
booster.run();

System.out.println("Pressure after booster: " + booster.getOutletPressure() + " bara");

// Second pipeline segment (35 km to platform)
AdiabaticPipe pipe2 = new AdiabaticPipe("Flowline 2", booster.getOutletStream());
pipe2.setLength(35000.0);
pipe2.setDiameter(0.254);
pipe2.run();

System.out.println("Arrival pressure: " + pipe2.getOutletPressure() + " bara");

Example 3: Twin-Screw Pump for Slugging Flow

// Twin-screw pump handles slugs better than helico-axial
SubseaBooster booster = new SubseaBooster("Slug Handler", manifoldStream);
booster.setBoosterType(SubseaBooster.BoosterType.MULTIPHASE_PUMP);
booster.setPumpType(SubseaBooster.PumpType.TWIN_SCREW);
booster.setWaterDepth(300.0);
booster.setOutletPressure(120.0);

// Twin-screw specific parameters
booster.setMaxGVF(0.98);           // Can handle 98% GVF
booster.setSlugTolerance(true);    // Designed for slugging

booster.run();

System.out.println("Differential pressure: " + booster.getDifferentialPressure() + " bar");

Example 4: Wet Gas Compressor

// High GVF stream from gas well
SystemSrkEos gasFluid = new SystemSrkEos(323.15, 60.0);
gasFluid.addComponent("methane", 88.0);
gasFluid.addComponent("ethane", 5.0);
gasFluid.addComponent("propane", 2.0);
gasFluid.addComponent("n-pentane", 1.0);
gasFluid.addComponent("water", 4.0);
gasFluid.setMixingRule("classic");

Stream gasStream = new Stream("Gas Well", gasFluid);
gasStream.setFlowRate(100000.0, "kg/hr");
gasStream.run();

// Wet gas compressor
SubseaBooster compressor = new SubseaBooster("Subsea Compressor", gasStream);
compressor.setBoosterType(SubseaBooster.BoosterType.WET_GAS_COMPRESSOR);
compressor.setWaterDepth(800.0);
compressor.setOutletPressure(120.0);
compressor.setCompressionRatio(2.0);
compressor.setPolytropicEfficiency(0.80);

compressor.run();

System.out.println("Outlet temperature: " + (compressor.getOutletTemperature() - 273.15) + " °C");
System.out.println("Power: " + compressor.getPower("MW") + " MW");

Example 5: Booster with Mechanical Design

import neqsim.process.mechanicaldesign.subsea.SubseaBoosterMechanicalDesign;

// Create booster
SubseaBooster booster = new SubseaBooster("Export Booster", stream);
booster.setBoosterType(SubseaBooster.BoosterType.MULTIPHASE_PUMP);
booster.setPumpType(SubseaBooster.PumpType.HELICO_AXIAL);
booster.setWaterDepth(600.0);
booster.setDesignPressure(250.0);
booster.setDesignTemperature(150.0);
booster.setPowerRatingMW(6.0);

// Get mechanical design
SubseaBoosterMechanicalDesign design = booster.getMechanicalDesign();

// Configure design parameters
design.setDesignLife(25);          // years
design.setMaterialGrade("6Mo");
design.setServiceType("Sour");
design.setCorrosionAllowance(3.0); // mm

// Calculate design
design.calcDesign();

// Get weight estimate
System.out.println("Booster dry weight: " + design.getDryWeight() + " tonnes");
System.out.println("Foundation weight: " + design.getFoundationWeight() + " tonnes");

// Get JSON report
String report = design.toJson();

Design Standards

Applicable Standards

Standard Title
API RP 17Q Subsea Equipment Qualification
API RP 17V Subsea Boosting Systems
DNV-ST-E101 Drilling Plants
ISO 13628-6 Subsea Production Control Systems

Design Considerations

Parameter Typical Range Unit
Water Depth 200-3000 m
Design Pressure 150-400 bar
Design Temperature -10 to 150 °C
Power Rating 1-15 MW
Design Life 20-30 years
Availability >95% -

Power Supply Options

Option Typical Range Application
Long step-out AC 50-150 km Moderate distance
DC transmission 100-300+ km Long tieback
All-electric Any Modern systems
Hydraulic <30 km Legacy systems

Turndown and Operating Envelope

Speed Variation

// Variable speed operation
double[] speeds = {60, 70, 80, 90, 100};  // % of rated

for (double speed : speeds) {
    booster.setSpeed(speed);
    booster.run();
    
    double flow = booster.getOutletStream().getFlowRate("m3/hr");
    double dp = booster.getDifferentialPressure();
    double power = booster.getPower("MW");
    
    System.out.printf("Speed: %.0f%%, Flow: %.0f m³/hr, ΔP: %.1f bar, Power: %.2f MW%n",
        speed, flow, dp, power);
}

Affinity Laws

For centrifugal-type boosters:

\[\frac{Q_2}{Q_1} = \frac{N_2}{N_1}\] \[\frac{H_2}{H_1} = \left(\frac{N_2}{N_1}\right)^2\] \[\frac{P_2}{P_1} = \left(\frac{N_2}{N_1}\right)^3\]

Where:

API Reference

SubseaBooster

// Constructors
SubseaBooster(String name)
SubseaBooster(String name, StreamInterface inletStream)

// Booster configuration
void setBoosterType(BoosterType type)
BoosterType getBoosterType()
void setPumpType(PumpType type)
PumpType getPumpType()

// Design parameters
void setWaterDepth(double depth)
void setDesignPressure(double pressure)
void setDesignTemperature(double temperature)
void setPowerRatingMW(double power)

// Operating parameters
void setOutletPressure(double pressure)
void setDifferentialPressure(double dp)
void setSpeed(double percentOfRated)
void setEfficiency(double efficiency)
void setCompressionRatio(double ratio)
void setPolytropicEfficiency(double efficiency)

// Performance curves
void setPerformanceCurve(double[] flows, double[] heads)
void setEfficiencyCurve(double[] flows, double[] efficiencies)

// Mechanical design
SubseaBoosterMechanicalDesign getMechanicalDesign()

// Run simulation
void run()
void run(UUID id)

// Results
StreamInterface getOutletStream()
double getOutletPressure()
double getOutletTemperature()
double getDifferentialPressure()
double getPower(String unit)

BoosterType Enum

enum BoosterType {
    MULTIPHASE_PUMP,
    LIQUID_PUMP,
    WET_GAS_COMPRESSOR,
    DRY_GAS_COMPRESSOR,
    SEPARATOR_BOOSTER
}

PumpType Enum

enum PumpType {
    HELICO_AXIAL,
    TWIN_SCREW,
    COUNTER_ROTATING_AXIAL,
    ESP,
    CENTRIFUGAL_SINGLE,
    CENTRIFUGAL_MULTI
}