Flow Assurance Presentation - Rune Time 3

Flow Assurance and Multiphase flowScandpower Petroleum Technology

ppart III

Prof. Rune W. Time

Department of Petroleum EngineeringUniversity of Stavanger

Seminar at Aker Solutions, Stavanger – May 31st, 2011

O li d i h d lOutline and time schedule

I : 8.30 – 9.15 Flow regimes and impact on phase slippage, fluid concentrations and pressure drop in pipelinespipelines

II : 9.25 – 10.15 Hydrates, wax and asphaltenes

III: 10.25 -11.00 Multiphase flow – influence from int f c s c mp ssi n ff cts nd s interfaces, compression effects and waves

Seminar at Aker Solutions, Stavanger - May31st, 20112

PART III

Multiphase flow- Influence from interfacesInfluence from interfaces,

compression effects and waves


l Slug types

• Hydrodynamic slugging (Horizontal pipes)

• Terrain induced slugging (liquid accumulation and U-tube)Terrain induced slugging (liquid accumulation and U tube)

• Severe slugging (stronger version of terrain slugging)

Severe slugging, or terrain induced slugging, may gg g, gg g, yoccur at low flowrates when a downwards inclined or horizontal pipeline is connected to a vertical riser. It is characterised by periods of feed starvation It is characterised by periods of feed starvation for the receiving process, followed by periods of very high oil and production rates.

4Seminar at Aker Solutions, Stavanger - May31st, 2011

Terrain induced slugging

http://pipeliner.com.au/news/super_cooper_sa

t b i intos_cooper_basin_pipeline_network/012082

Gas

Cond


Slug catcher facility - Melkøya


Severe sluggingFigure 8 1: Typical severe slugging geometryFigure 8.1: Typical severe slugging geometryREF: Rune W. Time: Multiphase compendium

http://www.ljll.math.upmp j pc.fr/gallery/files/coquel_

slugging-en.htm


Structural damages due to high flows

Structural damage due Structural damage due to slug loading

Flexible riser configurationsmay fatigue and failIAF Das: “The Characteristics and Forces due

t Sl i 'S‘ Sh d Ri ” PhD Th i may fatigue and failwith severe slugging

to Slugs in an 'S‘ Shaped Riser”, PhD Thesis Cranfield 2003


Mechanical loads on bends due to severe slugging

B dBend

Flow

Resultant force on bend:2FR 2 Av


Minimizing Severe slugging

REF: Rune W. Time: Multiphase compendium

Figure 8.3: Pressure drop in riser, choke and combined riser + choke, for fixed liquid flow rate. From Schmidt et al.,1985

Other solutions:- Riser gas lift ?....


Wave propagation in two-phase flow

• Surface waves: • Stratified flow Interface friction Liquid transport• Slug flow (see movie - later) g ( )

• Concentration waves in bubbly systems (wave speed may influence cross correlation flowmeters)p y

• Pressure waves – sound speed – choked flow


Stratified interface drag - I

Interfacial drag in stratified flows:

http://www.thermopedia.com/video/2/stratified_wave

Interfacial drag in stratified flows:• For stratified flow in pipelines the interface is found to be smooth for water for gas velocities less than approximately 3 m/s. At this velocity small amplitude regular Jeffrey waves appear at the interface.

• Above about 5 m/s Kelvin-Helmholtz waves are generated. For velocities of about 10 m/s droplets are spewed from the crest of the waves waves.

• For liquids with a viscosity greater than 15 centipoise the interface is smooth for gas velocities less than 5 m/s and Kelvin-Hetmholtz waves are generated above this velocity.

• The appearance of Kelvin-Helmholtz waves is accompanied by a large increase in the interfacial stress both for water and for viscous liquids increase in the interfacial stress both for water and for viscous liquids.

R. V. A. Oliemans (ed.), Computational fluid Dynamics for the Petrochemical Process Industry. ”Separated flowmodelling and interfacial transport phenomena”, THOMAS J. HANRATTY

12

ifi d i f d IIStratified interface drag - IITh h i ht f t tifi d fl i i li hl f th • The wave heights for stratified flows in pipelines are roughly of the

order of 0.5 to 5 mm so they protrude into the gas space an appreciable distance.

• The magnitude of the form drag should increase linearly with the wave height, h, and with the number of waves per unit length.

A c rr l ti n b Andrits s b s d n m sur m nts f r 2 54 cm nd 9 53 • A correlation by Andritsos based on measurements for 2.54 cm and 9.53 cm pipelines and for liquids with viscosities of 1-70 centipoise is:

i ii 21

f h1 18 , where ff U

Here fs is the friction factor for a smooth interface.

1s G2f U

Example: h = 5mm, = 2cm fi / fs = 5.5

More than five times higher interfacial drag!

13

g g


Hydrodynamic slugging

Kadri Mudde, Oliemans, Bonizzi, Andreussi : ”Prediction of the transition from stratified to slug flow

or roll-waves in gas–liquid horizontal pipes”,

International Journal of Multiphase Flow 35 (2009) 1001–10101010

Kelvin-Helmholtz

Video: K-H Ugs4p4 Uls 0p3 later2instability Slug flow 14


Interfaces - liquid accumulation, wallwetting, and corrosion

Wet gas pipelines: Wet gas pipelines: CO2 and H2S may attack ”washed” pipeline parts lacking inhibitor .

H i d l t

Transportability

Hanging droplet

Flattened droplet

N b d D t d ”T f Li C i d W t C d ti R t i W t

Flattened droplet

Nyborg and Dugstad: ”Top of Line Corrosion and Water Condensation Rates in WetGas Pipelines”, 2007:

Water condensing in the top of a wet gas pipeline will form small droplets or a thin film on thet l f Th d d t b idl t t d ith i


steel surface. The condensed water can become rapidly supersaturated with corrosionproducts, resulting in increased pH and iron carbonate film formation.

Pressure waves, choked flow- and process control challenge

Case: The pipeline carries a dispersed bubble flow. Valve A is opened 1:100 (relative pipe). The flow does not change when valve B is p p gregulated. What is going on?

Flow upstream A; Qmix = 15 L/s , Gas fraction 10%, pipeline D = 10cmMixture velocity, Umix = 1.9 m/sMixture velocity, Umix 1.9 m/sValve opening (ratio area to pipe area): 1:100

Mix velocity in pipe restriction Flow velocity in valve A 190 m/s.With h hi h f ti thi l d t h k d ( i ) fl ! With such high gas fraction this leads to choked (sonic) flow !

Choked flow can give loss of “conventional control”. However,h l B i ffi i tl h k d l A it th h kiwhen valve B is sufficiently choked, valve A exits the choking

condition, and B gets back control. 16Seminar at Aker Solutions, Stavanger - May31st, 2011

Choked flowChoked flow): Flow speed cannot exceed sound speed in the relevant fluid

Chung, Park, and Lee: “Sound speed criterionSound speed criterion for two-phase critical

flow”, Journal of Sound and Vibration 276 (2004) 13–26


The challenge of calculatingpressure drop in long traverses

h d l h The pressure gradient varies along the pipe due to variation in pipe diameter, inclinationand mixture density (pressure dependent) outP

Pdl

out inP P P Pressure at exit:

inP

out in

Sum of pressure drop in all pipe segment

Challenge in multiphase flow: • The pressure profile depends on the pressure! • Requires iterative numerical solver


• Requires iterative numerical solver.

18

Numerical simulators available

Commercial simulatorsCommercial simulatorsSteady-state:• PIPESIM (Schlumberger)• PIPEFLOW (SPT Group)

Dynamic , transient:HYSYS 1D (h // h / / h )• HYSYS, 1D (http://www.aspentech.com/core/aspen-hysys.aspx)

• TACITE, 1D (http://www.ann.jussieu.fr/ERTint/pdf/Tacite.pdf)• OLGA, 1D (IFE 1908, Scandpower 89-92, WOLGA,SPT Group)• LEDA 2D-3D (TotalFinaElf,Conoco and SINTEF)

Well flow and drilling : Drillbench (IRIS)

Quality assurance in using commercial packages:- Make sure to have simple inhouse models (semianalytical + numerical) for

checking and comparisons (”common sense”), e.g.h i i d l l T i l d D kl d d f !mechanistic models a la Taitel and Dukler - needed for transparency !


Taitel and D kl d lDukler model

Physics basedy

Liquid holdup

Flow regime modelse.g. slug (K-H):

Pressure gradient

20

Model output – Taitel and Dukler ”in-house” program

1

0 5

0.6

0.7

0.8

0.9

/D Y 0

X = 23.5829 hL/D = 0.87219

Liquid height for stratified flowcase

0.1

0.2

0.3

0.4

0.5

h L/ Y = 0

10-2 100 102 1040

0

X

80

100

on

Y = 0 2

UGS = 0.01 m/sULS = 0.01 m/s

0

20

40

60

og D

ukle

r fun

ksjo X2 = 556.152

X = 23.5829

hlt = 0.87219

uG = 0.13419 m/s uL = 0.010805 m/s

ReG = 65.8739 ReL = 137.2857

Flow regime determination:

Flow regime determinationand pressure gradient

-80

-60

-40

-20

Res

idua

l Tai

tel o g

- Stratified Smooth - Stratified Wavy

FINAL REGIME:Stratified WavyPressure gradient:

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-100

80

hL/D

0.47121 (Pa/m]


QUIZ:A simple(st) case of two-phase flow

Horizontal pipelineEqual inflowQL = QG

Gas

Liquid

Stabilizedinterface ?

2

31

Liquid

• How to decide?

2

How to decide?

• Any guideline principles after all ….. ?

Previous slide showed a calculation with Stratified flow, and equalflowrates of gas and liquid :

Liquid height = 0.87. Pipe diameter - Liquid level rises!22


Flow assurance and multiphase flow at UISpStaff members

• Malcolm Kelland (Hydrate LCI, production chemicals)

• Thor Martin Svartås (hydrate kinetics drag reducers natural• Thor Martin Svartås (hydrate kinetics, drag reducers, naturalgas)

• Aly Hamouda : Wax asphaltenes heavy oils IOR CO2 • Aly Hamouda : Wax, asphaltenes, heavy oils, IOR, CO2 injection

• Rune W Time : Multiphase flow in pipelines CO2 Rune W. Time : Multiphase flow in pipelines, CO2 sequestration, multiphase metering and advanced flowinstrumentation

In addition several PhD’s and postdocs


Multiphase flow laboratory

24


Multiphase Projects at UIS - I

PROJECTS d h f ili i UiS ( h // i ) PROJECTS and research facilities at UiS ( http://www.uis.no ) and IRIS

Gas-liquid and liquid-liquid flows: Gas liquid and liquid liquid flows: - medium scale (20 m pipelines oil+air, 10 m water + air) - flow regime analysis of gas-liquid flows in horisontal pipes (oil-air) - terrain and severe slugging (with Iris) - transient flows and cavitation flows (with Flow Design Bureau and Univ of - transient flows and cavitation flows (with Flow Design Bureau and Univ. of Minneapolis) - drag reducers for oil-water production systems

Drilling and well technology (with Iris) Drilling and well technology (with Iris) - underbalanced drilling and managed pressure drilling (with Iris and Petrobras) - down-hole metering systems (Aker Maritime, IPCsystem)

Liquid particle flow Liquid particle flow - hole cleaning and cuttings transport (particle transport) in near horisontal pipes (10 m slightly flow loop - with Statoil) - erosion by particles in wells and production lines


M l i h P j UI IIMultiphase Projects at UIS - II

Multiphase flow metering techniques in our laboratory X ray multisensor (Financed by the Norwegian Research Council NRC) - X-ray multisensor (Financed by the Norwegian Research Council, NRC)

- Capacitance and impedance techniques (tomography - with Texaco, and norwegianresearch institutes) - Ultrasonics for measurement of thin liquid layers in pipes (for Conoco Phillips)Ultrasonics for liquid particle slurries ( for Total) - Ultrasonics for liquid particle slurries ( for Total)

- PIV and LDA (Dantecdynamics systems) - High speed video and PIV (Financed by NRC)

Also Also - Microwave multiphase flowmeters (with MPM – MultiPhase Meters)( http://www.mpm.biz/Portals/39/Performance%20Oct%2005.pdf )

CFD simulation: Fluent Comsol MultiphysicsCFD simulation: Fluent, Comsol Multiphysics

In addition projects within combustion and gas-dynamics - CO2 capture in oxy-fuel processes (with IRIS, NRC, StatoilHydro and Shell) - CO2 adsorption dynamics in turbulent water based systemsCO2 adsorption dynamics in turbulent water based systems


End

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Flow Assurance Presentation - Rune Time 3