Olga Handbook.pdf
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Transcript of Olga Handbook.pdf
OLGAS - re l iabi l i ty for mult iphase f low
OLGAS is the steady state flow correlation based on OLGA®
- the industry standard for dynamic multiphase flow
be
dyn
am
ic
OLGAS
Using the OLGA® model for steady state calculationsOLGAS is a mechanistic point model that calculates pressure gradients, liquid hold-up and flow pattern at a specific section of pipe/tubing.
OLGAS is available in both the 2- and 3-phase options.
Being a reference model with superior predictive capabilities, OLGAS is the natural default flow model in all steady state applica-tions.
Why OLGAS?OLGAS is the superior mechanistic model that has been
developed from laboratory and test data supplied
by operating companies since the mid 80’s. OLGAS
is continuously being developed in conjunction with
the OLGA® dynamic simulator and the power in the
development has never been stronger than today.
OLGAS updates are typically released twice per year.
The correlation challengeEngineers are charged with the responsibility to find
the appropriate multiphase correlation for systems
- especially when:
Lack of appropriate data when a new well or
pipeline is being designed.
“Industry Standard” correlations do not fit the
available test data for some or all of my wells.
Different correlations are used to match similar
wells.
The same correlation yield incomparable results in
different application.
OLGAS is developed to support the engineer in these
situations. No other flow model is valid in a wider
operation than OLGAS.
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The OLGAS codeThe OLGAS program is a steady-state multiphase model for
the calculation of pressure drop, local phase volume frac-
tions and related information at a single point in a pipeline.
The OLGAS point model is available as a FLEXlm protected
dll, which may be dynamically linked to (e.g.) a steady-state
pipeline/well flow simulator.
The OLGAS dll has three main interfaces defined:
2 phase interface
3 phase interface
3 phase interface w/effective oil and water phase vis-
cosity including water/oil dispersion effects
There are also defined interfaces for license control, extended
input and output:
The OLGAS DLL is currently available on the Winnt, Win32 and
Linux. Default programming languages available for interfac-
ing is Fortran 77/90/95 and C/C++.
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OVIP – a key driver in the OLGAS developmentOVIP (OLGA® Verification an Improvement Project) is a
multi-client joint industry research and development
program for validation and improvement of OLGA®. Over
the last decade a chain of OVIP projects have dramatically
improved the performance of the point model OLGAS. The
current OVIP program is supported by BP, Chevron, ENI,
ExxonMobil, Petrobras, Statoil, Total and Shell.
OVIP embodies by far the largest multi-
phase flow data collection ever assembled.
Containing both experimental and field data,
including gas/condenasate pipelines, lower
GOR pipeline, well, and transient data, OVIP
contributes to significant improvements in
OLGA® and OLGAS.
Some of the recent improvements includes
important phenomena in stratified flow:
Wall shear stress models
Droplet entrainment models
Gas entrainment in the liquid layer
Droplet deposition on the pipe wall
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3rd Party AvailabilityEach 3rd-party supplier is afforded identical implementations of OLGAS to assure that the flow correlation results provided by one simulator will be comparable to those from another. Vendors typically offer bi-annual upgrades.
OLGAS is available, with a product specific license, from a number of leading vendors of steady state simulators:
Aspentech - Hysys®
Calsep – DepoWax®
Honeywell - UniSim®
Invensys - PIPEPHASE®
Neotech - Wellflo® & Pipeflo®
Petroleum Experts - Prosper® & GAP®
Schlumberger - PIPESIM® familyand others
••••••••
OVIP – with focus on wellsWork on multiphase flow in vertical upward wells and risers
shows that there are fundamental differences between the
flow in small and large diameter pipes. In flow patterns occur-
ring in vertical upward flow the relative importance of flow
regimes is very different for small and large pipes. In the OVIP
2002-03 project, OLGA was modified to take this better into
account. Also, a new correlation for entrainment in annular
flow by Pan & Hanratty (2003) has been modified based on
the unique high-pressure data from the
SINTEF Multiphase Flow Laboratory. These
enhancements have improved OLGAS pre-
dictions of pressure drop in vertical annular
flow in wells and risers.
Experiments in the Well Loop at the Institute for Energy Technology (IFE)
Selected References • Nossen, J., Shea, R.H., and Rasmussen, J.: New
developments in flow modelling and field data
verification: Banff 2000.
• Bendiksen, K., Malnes, D., Moe, R. & Nuland, S.:
The Dynamic Two-Fluid Model OLGA: Theory
and Application. SPE Production Engineering,
May 1991, pp. 171-180
• Shea, R., Rasmussen, J., Hedne, P. and Malnes,
D.: Holdup predictions for wetgas pipelines
compared. Oil & Gas Journal, May 19, 1997
OLGAS vs Beggs & Brill 7.5” ID 1deg incl
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MEASURED LIQUID HOLDUP
PRED
ICTE
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OLD
UP
www.olgaworld.com [email protected]
SPT Group is the world leader in dynamic modelling
for the oil and gas industry. Employing highly
skilled professionals worldwide, SPT Group
provides a combination of software and
consulting services within multiphase
flow and reservoir engineering.
www.sptgroup.com
USA, Houston Tel: +1 281 496 9898 Norway, Oslo Tel: +47 64 84 45 50
Mexico, Mexico City Tel: +52 555 211 9211 Norway, Bergen Tel: +47 55 54 38 70
Australia, Perth Tel: +61 8 9286 6500 Germany, Hamburg Tel: +49 40 27 85 88 0
UAE, Dubai Tel: +971 4 391 4130 Russia, Moscow Tel: +7 095 135 88 16
Italy, Milan Tel: +971 50 453 9642 UK, London Tel: +44 1483 307 870
Malaysia, Kuala Lumpur Tel: +60 12 6766 360