Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient
Simulation Tool – Gas and Dense Phase Modelling
AOG Conference March 2015
Presented by Andy Jones, General Manager, Perth
www.xodusgroup.com
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Across the lifecycle . Across disciplines . Across the world
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Contents
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Introductions
Fundamental caveats
Fit for purpose modelling functionality
Dense phase modelling in Hysys dynamics
Gas and dense phase modelling case studies
Summary of benefits
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Introductions
Andy Jones, General Manager, Perth Office
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Dynamic process simulation (Hysys, UniSim etc.)
Online monitoring package specification, development and commissioning
Modelling package integration (OLGA – Hysys / UniSim, Hysys – Pipesim)
Use of modelling packages to aid operations and commissioning
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Fundamental Caveats
> Hysys / UniSim are not a replacement for OLGA / Ledaflow (or similar
rigorous multiphase fluid simulation software) in all circumstances by any
means
> There are only specific cases in which the concepts presented here are
applicable
> But where there are opportunities to use Hysys / UniSim, the benefits can
be significant
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Fit-For-Purpose Functionality
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Fit-For Purpose
Stakeholders agree prioritisation
of functionality
Accuracy
Based on agreed functionality,
stakeholders assess minimum
accuracy standards
Robustness
Continually assess the systems
uptime and “operating envelope”
Speed
For simulation inclusive systems,
fast computation is essential
Essential Model Attributes for Success
Speed
Accuracy
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Robustness
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Dense Phase Modelling in Hysys Dynamics
Benefits
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Quick to build
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Compositionally tracked
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Transient
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Robust
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Easy to automate
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Easy to integrate with other packages
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Fast – typically 40 times real time
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Accurate in gas and dense phase
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Cheaper licensing
Challenges
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Two phase results may be less
accurate – specifically at very low
liquid loading
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Benchmarking required
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Case Study 1 – Online Monitoring of a Dense Phase Pipeline
> Single phase dense gas
pipeline
> Online Hysys dynamics
models
> 3 instances of the model
Real time
‘What if’
Predictive
> Primary functions
Liquids management
Hydrocarbon
accountancy
Process visualisation
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Case Study 1 – Online Monitoring of a Dense Phase Pipeline – Initial Status
FPSO 1
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Dense phase gas pipeline
No online chromatograph
Daily / weekly samples
No difficulties with allocation
No difficulties with operations
Receiving Platform
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Case Study 1 – FPSO 1 Only Phase Envelope
Platform Phase Envelope
Dense Phase
Liquid
Two
Phase
Relatively
large headroom to
avoid generation
Gas of liquids
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Case Study 1 – Problem – FPSO 2 Exports Rich Gas
FPSO 2
FPSO 1
Receiving Platform
> Injection of NGLs
> Online chromatograph
> Multiple import / export
operating modes
$?
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Case Study 1 – Combined Feed Phase Envelope
Platform Phase Envelope
Small headroom to
avoid generation
of liquids
Dense Phase
Liquid
Two
Phase
Gas
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Case Study 2 – UK North Sea Multiphase Pipeline System
> Multiphase pipeline
> Online linked COMPAS and
UniSim models
> 2 instances of the model
Real time
‘What if’
> Primary functions
Liquids management
H2S / CO2
management
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Case Study 3 – Integrated Topsides and Subsea Flowlines Modelling
Value Summary
From
Wells
DTU B
Hysys
Produced
Water
From
Wells
DTU C
Produce copies of the OLGA models in Pipesim
Hysys
Integrate all models into one Hysys model
+
=
Full accurate solutions in minutes!
2 months reduced to 3 days!
Produced
Water
Fuel Gas
Dry Gas Export
From
Wells
DTU A
Hysys
Central
Processing
Facility
Live Liquids Export
Hysys
Produced
Water
DTU = Dry Tree Unit
LNG
Hysys
Produced
Water
Key
Gas Pipeline
Liquids Pipeline
Produced Water
Onshore
LNG
Plant
Condensate
Storage
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Case Study 3 – Benchmarking Results
Hydrocarbon Phase Envelope Comparison
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Correlations showed that for
this application the PVT data
was almost identical with
those used in PVT Sim
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Presuure (bara)
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60
40
20
0
-300
-200
-100
0
100
200
300
400
500
Temperature (deg C)
Hysys Hydrocarbon Phase Envelope
PVTSim Hydrocarbon Phase Envelope
Pipesim Hydrocarbon Phase Envelope
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Case Study 4 – Coal Seam Gas to LNG Simulation
Gas Gathering
Networks
Detailed Gas
Compression
Facilities
High Pressure
Pipeline Network
Energy flow = 2300
Wobbe index = 49.2
Mass flow = 9.0
Std. Vol flow = 2100
Pressure = 12.76
Temp = 30.2
210 TJ/d
TJ/d
MJ/m3
mT/yr
MMscfd
MPa
DegC
LNG Plant
GPF 1
221 TJ/d
GPF 2
GPF
204 TJ/d
GPF 3
GPF
Etc.
GPF
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Using Hysys / UniSim as a Fast, Accurate and Robust Pipeline Transient Simulation Tool
Summary of the Benefits of Modelling Pipelines in Hysys / UniSim
HARDER
> More robust without sacrificing accuracy
> Fully automated solutions removing human error
BETTER
> Increased productivity
> Reduced downtime
> More cost effective
FASTER
> Reduced detailed design turnaround times
> Increased run times
STRONGER
> Fully integrated solutions
> Using industry standard software which is future proofed
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Across the lifecycle . Across disciplines . Across the world
www.xodusgroup.com
Thank you – any Questions?
www.xodusgroup.com
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