Two Phase Fluid Mechanics

8/10/2019 Two Phase Fluid Mechanics

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Two phase fluid mechanics

Instructor:

Valid Taghikhani

Fall 1388Department of Chemical and Petroleum Engineering, Sharif University of Technology

http://localhost/var/www/apps/conversion/tmp/Taghikhani/CV/09-10-2009.pdf

http://www.sharif.edu/

http://www.sharif.edu/

http://localhost/var/www/apps/conversion/tmp/Taghikhani/CV/resume.pdf

http://localhost/var/www/apps/conversion/tmp/Taghikhani/CV/09-10-2009.pdf



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Course syllabus

• Introduction to multiphase flow

• Hydrocarbon reservoirs

• Liquid mixture properties

• Gas/liquid mixture properties• Basic concepts of two phase flow

• Mechanistic/empirical models

• Steady state correlations for horizontal, vertical and inclined

pipes.• Pigging and slug catchers

• Unsteady state multiphase flow

• Software application (OLGA, pvt-sim, PIPEPHASE)



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References

• Two phase flow in pipes, 6th ed., J P Brill, H P Beggs.

• Multiphase flow in wells, J P Brill, SPE communication.

• Some technical papers.



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Course grading scheme

• Written exams (up to 80%)

• Assignments (up to 5%)

• Class projects (up to 15%)

A mailing list and a taker to moderate the mailing listrequired. Who is the taker!?



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Multiphase Production system

Well

Reservoir

Surface

equipment



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Session 2:

Hydrocarbon phase behavior, flash calculations

and pvt-sim



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Flash separation



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Main objective of flash calculations

• Optimum separation conditions: P and T

• Composition of separated oil and gas phases

• Producing gas/oil ratio

• API gravity of the stock tank oil

• Oil formation volume factor



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Optimum conditions leads to:

• Minimum gas/oil ratio

• Minimum oil formation volume factor

• Maximum stock tank API gravity



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Session 3:

Fluid properties



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Standing’s correlation



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Vasquez-Begg’s correlation



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Session 3:

Basic concepts of two phase flow



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At Low Flow Rates Liquid Accumulates in the Flowline Increasing

the Pressure Drop

Friction

Dominated

GravityDominated



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Liquid Holdup Depends on Flowline Geometry and Flowrate



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Liquid Holdup Can Lead to Liquid Slugging

• There are two types of slugging: – Hydrodynamic: Induced by the holdup and superficial velocities

– Terrain: Induced by geometry changes in which liquid can accumulate

• In Real Flowlines, Hydrodynamic and Terrain Slugs Can Interact:

– Difficult to predict slug length and frequency

• Slugging can lead to surges of liquid that can overwhelm slugcatchers

• Liquid holdup leads to increased pressure drops and reduced flow

• Pigs can be used to periodically remove liquid from the flowline



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Pigging

• Gas lines in particular are periodically pigged to remove accumulated liquid

• The large liquid slug is caught in a large separator called a “Slug Catcher”

Flow

Pig



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Types of Pigs

• Spheres: – Easy to handle.

– Can be re-inflated to compensate for wear.

– Negotiate irregular bends.

– Little energy for movement < 2psi.

• Foam Pigs: – Inexpensive and versatile.

– Can be fitted with brushes to remove deposits.

• Steel Pigs: – Durable with replaceable sealing elements.

– Can also be equipped with brushes and blades.

• Solid-Cast Pigs: – Light in weight, allow for longer and more efficient sealing.



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Slip velocity

between oil

and gasphases

Voil

VGas

Voil

VGas

Voil

VGas

Voil

VGas



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Session 4:

Gas Flow in Pipelines: A single phase flow



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Gas flow in horizontal pipe



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Sessions 4 and 5:

two phase models for Vertical flow



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Hagedorn and Brown Model



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If constants are included:



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Beggs and Brill Method



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Sessions 6 and 7:

two phase models for horizontal flow

Two Phase Fluid Mechanics

Documents

Transcript of Two Phase Fluid Mechanics