1 - crude oil treatment - separation

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ingPRO01198 – CRUDE OIL TREATMENT - Separation

SURFACE PROCESSING

A – CRUDE OIL TREATMENT

I- SEPARATION

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SEPARATION – Contents

1- Well effluents Generalities

2- Gas/liquid separation

-equilibrium calculations

-influence of the process recovery rate

3- Separator sizing principles

-diphasic vertical separator

-diphasic horizontal separator

4- Gas/Liquid Separator different types

5- Foaming (difficult gas/liquid separation)

Next course: Oil/Water separation

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1- Well head effluents

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WELL HEAD EFFLUENTS

WELLHEADWELLHEADEFFLUENTSEFFLUENTS

GASGAS

OILOIL

WATERWATER

FORMATION SAND AND SILTFORMATION SAND AND SILT

COLLOID STATE CLAYCOLLOID STATE CLAY

CORROSION PRODUCTCORROSION PRODUCT

WAXESWAXES

ASPHALTENESASPHALTENES

MINERAL CRYSTALSMINERAL CRYSTALS

NaClNaCl CaCO3 BaSO4 SrSO4CaCO3 BaSO4 SrSO4

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SEPARATION CHAIN

EMULSIONEMULSION

INTERMINGLED WATER/OILINTERMINGLED WATER/OIL

FOAMSFOAMSLIQUID DROPLETS LIQUID DROPLETS

IN GASIN GASWELLHEAD EFFLUENTSWELLHEAD EFFLUENTS

CONDENSATECONDENSATE

FREE WATERFREE WATER

GASGAS--LIQUIDLIQUID

SEPARATIONSEPARATION

GAS TREATMENTGAS TREATMENT

DEHYDRATIONDEHYDRATION

CONDENSATE CONDENSATE

RECUPERATIONRECUPERATION

EMULSIONEMULSION

TREATMENTTREATMENT

WATERWATER

EMULSIONEMULSION

GASGAS

WATERWATER

OPERATIONS SOMETIMESOPERATIONS SOMETIMESCARRIED OUTCARRIED OUT

in 1 PROCESS EQUIPMENTin 1 PROCESS EQUIPMENT

export

crude

OILOIL--WATERWATER

SEPARATIONSEPARATION

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SOURCE OF WATER

WATER AND OIL ZONES IN RESERVOIR WATER AND OIL ZONES IN RESERVOIR

OILOIL

OILOIL

* Active Water Reservoir* Active Water Reservoir

* Water Injection : Injection of 1* Water Injection : Injection of 1--2 volumes of water2 volumes of water

Production of 1Production of 1--5 volumes of water per oil volume5 volumes of water per oil volume

* Faulty Cementing Job* Faulty Cementing Job

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SOURCE OF SALT

SALTSALT

RESERVOIR WATERRESERVOIR WATER

INJECTED WATER (SEA WATER)INJECTED WATER (SEA WATER)

*If Salt Content>10mg/l , Reservoir Water INGRESS*If Salt Content>10mg/l , Reservoir Water INGRESS

Produced Water Not Detected; only salt content is measured Produced Water Not Detected; only salt content is measured

*HASSI MESSAOUD : CAMBRIEN WATER 370g/l*HASSI MESSAOUD : CAMBRIEN WATER 370g/l

Low Water CutLow Water Cut HIGH SALT CONTENTHIGH SALT CONTENT

0,1%0,1% SALT CONTENT 370 mg/lSALT CONTENT 370 mg/l

*Sometimes HIGH SALT CONTENT without WaterEAST BAGDAD As much as 265ppm of salt ***

* Same for Hassi Messaoud - Fateh - ABK -ZadcoThis Phenomenon is limited in Time

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OIL , BSW and GOR EVOLUTION WITH TIME

Production

106 m3 / an3

2

1

GORGOR

OILOIL

BSW

%

3030

2020

1010

300300

200200

100100

YEARS

BSWBSW

11 22 33 44 55 66 77 88 99 1010 1111 1212

GOR

�� difficulty to design separation equipment

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CONTRACTUAL WATER AND SALT CONTENTS

TRANSPORTERSTRANSPORTERS : LIMITATION FOR WATER CONTENT: LIMITATION FOR WATER CONTENT

*PIPELINE *PIPELINE -- PIPE OVER LOADINGPIPE OVER LOADING

BSW <= 0.5%BSW <= 0.5%

-- CORROSION ( WATER + SALT )CORROSION ( WATER + SALT )

*BY SEA NO FIXED CONSTRAINTS*BY SEA NO FIXED CONSTRAINTS BUTBUT

-- ACCIDENTAL CONTAMINATIONACCIDENTAL CONTAMINATION

-- LOAD ON TOP CONTAMINATIONLOAD ON TOP CONTAMINATION

AGREEMENTAGREEMENT

PRODUCERSPRODUCERS

TRANSPORTERSTRANSPORTERS

REFINERSREFINERS

CRUDE OIL MARKETINGBusiness is

business!!$$

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1 ELECTROSTATIC DESALTER1 ELECTROSTATIC DESALTER SALT CONTENT <5mg/lSALT CONTENT <5mg/l

* SCALE DEPOSIT INSIDE EXCHANGERS* SCALE DEPOSIT INSIDE EXCHANGERS

* DISTILLATION UNITS CORROSION

* RESIDUAL QUALITY DEGRADATION* RESIDUAL QUALITY DEGRADATION

95 % EFFICIENCY 95 % EFFICIENCY INLET SALT CONTENT < 100 mg/l INLET SALT CONTENT < 100 mg/l INLET SALT CONTENT < 100 mg/l

EUROPEAN REFINERIES

REFINERY : Salt...100 mg/lREFINERY : Salt...100 mg/l Water....0,2%Water....0,2%

TRANSPORT : Salt...60 mg/lTRANSPORT : Salt...60 mg/l Water....0,5%Water....0,5%

BSW in Production Fields < 0.5 %BSW in Production Fields < 0.5 %BSW in Production Fields < 0.5 %

PRODUCTION FIELD SPECIFICATIONS

CONTRACTUAL WATER AND SALT CONTENTS

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DEHYDRATION

TO WITHDRAW WATER DISPERSED IN CRUDE STRESSINGTHE WATER CONTENT

DESALTING

TO GET THE SALT SPECIFICATION WHEN THIS IS NOT THEDIRECT RESULT OF COMPLYING THE WATER SPEC.

DESALTING IS A DEHYDRATION TRT SET PREVIOUSLY WITH WASH WATER SOFTERTHAN RESERVOIR WATER

DEHYDRATION/DESALTING

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DEHYDRATION/DESALTING

With Reservoir Water at 350 g/l expressed as NaCl equivalent

0.1 % of Water Content 350 mg/l ( 123 PTB ) Salt Content

Salt Content < 60 mg/l Water Content < 0.017 %

SALINITY IS THE MOST RESTRICTING SPECIFICATION

With Reservoir Water at 40 g/l expressed as NaCl equivalent

0.1 % of Water Content 40 mg/l ( 14 PTB ) Salt Content

Salt Content < 60 mg/l Water Content < 0.15 %

WATER CONTENT IS THE MOST RESTRICTING SPEC.

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2- Gas/liquid separation

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GAS/LIQUID SEPARATION - Generalities

Hydrocarbon reservoir :

at reservoir conditions, generally one monophasic fluid

at surface conditions (P &T decrease), different components appear :

monophasic � polyphasic (gas + liquid)

hydrocarbon gas � condensation of heavier hydrocarbons liquid

water vapour � liquid water

THERMODYNAMIC BEHAVIOUR

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TREATMENT UNIT

AIM OF A TREATMENT UNIT

to recover all the different constituents

� Process specific to each development

to treat oil so that it is free of gas

to produce a gas as dry as possible (no water nor heavy hydrocarbons)

to remove water (and solids) from oil

to remove oil and solids from water (�Water Treatment specific courses)

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Pr

Pw

Pf

Pc

Pr Reservoir

Ps

Storage Shipping

Separation

Hydrocarbon production scheme

Pr: Reservoir pressure

Pf: Bottomhole flowing

pressure

Pw: Wellhead pressure

Pc: Choke pressure

Ps: Processing pressure

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Phase diagram

P

Liquid

Pr

Vapour

T0

Pf

0 %

100 %

Ps

Pc

Pw

Bubble Point

mole % liquid

30 %

15 %5 % 1 %

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METHANE - ETHANE MIXTURE PHASE DIAGRAM

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GAS PHASE ENVELOPPE SHAPE VERSUS GAS COMPOSITION

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at Constant composition

1. Flash process

If T constant = flash liberation

P1 V1T1

P2 V2T2

with P1 > P2

P1 V1T1

P2 V2T1

P1 > P2

P1 V1T1

P2 V2T2

P1 > P2T1 > T2

If T varies = flash separation

G1L1

P1 T1

G2L2

P2 T2

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total composition varies : there is draw off

2. Differential process

If T = constant = differential liberation

P1 > P2

G1L1

G2L2

GiLi

GS

P1 T1 P2 T2

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3. Composite process : combination of the two

GL

LG1L1 L2

GSLS

G2

PG TG PF TG P1 T1 P2 T2 Pa Ta

DifferentialLiberation (T cst)

Flash Flash Flash

Reservoir Separators Storage

PG

PF

P1

P2

Pa

Ta T2 T1 TG

P

T

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OPTIMAL SEPARATION PRESSURE IN HYDROCARBON PRODUCTION

FIELDS IS AN APPLICATION OF PHASE EQUILIBRIUM IN

THERMODYNAMICS

�AMOUNT OF LIQUID RECOVERED IS DEPENDENT OF THE

COMPOSITE PROCESS

�SEPARATION EFFICIENCY

YIELD (R) = final stock tank oil mass / mass of hydrocarbons entering

the processing unit

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Influence of the Process Recovery rate

Separation

P

Pb

13

15° TGT

Liberation

2

1

Rs

P

Flash

Differential

Pb

Rs =V gas produced

V oil at Pb

FROM PVT LAB EXPERIMENTS

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QUANTITIES OF FREE GAS ARE MORE IMPORTANT IN FLASH

LIBERATION THAN IN DIFFERENTIAL LIBERATION

SIMILARLY, VOLUME OF LIQUID IS GREATER IN A DIFFERENTIAL

PROCESS THAN IN A FLASH PROCESS

THE RELATIVE DIFFERENCE BETWEEN THE TWO CURVES DEPENDS

ON THE NATURE OF THE OIL : SLIGHT FOR HEAVY OILS AND

GREATER FOR VOLATILE OILS

�the higher the number of separation stages, the greater the liquid

recovery

�but P at 1st stage is governed by well head P (i.e. reservoir P)

�number of stages is a compromise between costs of installation and

liquid recovery

Influence of the Process Recovery rate

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GL

GL

Pi T1 Ps T1

Flash liberation

max gas & min liquid

One stage

Application / Field

Several stages

P1 T1 P2 T1

L

P3 T1

L

Ps T1

G

Separators Storage

G

L L

G G

Influence of the process Recovery rate

in each separator : flash liberationbut the whole chain of separators represents a differential separationmax of liquid recovery for an infinite number of separation stages

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Rule of thumb

Separation pressure at the different stages

n = number of stages + storage

Examples

GOR < 20 m3/m3 1°: 3-7 bara2°: Storage

GOR < 150 m3/m3 1° :10-20 bara2°: 2-6 bara3°: Storage

P sep. HP

P storage

n - 1

R =

GOR > 200 1°: 20-40 bara

2°: 5-15 bara

3°: 2-5 bara

4°: Storage

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PALANCA FIELD (ANGOLA)

Separation efficiency = final stock tank oil mass / mass of hydrocarbons

entering the processing unit

at P = 25, 20, 15 & 10 bar

at T = 105°C, 90°C, 75°C

Determination of the optimal P & T and number of separation stages to get the

higher separation efficiency

EXAMPLE OF APPLICATION

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Sep. Efficiency (%)

74

73.5

73

72.50 10 20

105

Pressure (bars)

25

90

75° C

75

74.5

75.5

76

76.5

5 15

PALANCA separation – output 2nd stage

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Sep. Efficiency (%)

74.5

74

73.5

730 6 12

105

Pressure (bars)15

90

75° C

75.5

75

76

76.5

77

3 9

Low pressure separator pressure

77.5

PALANCA separation – output 3rd stage

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Sep. Efficiency (%)

75.5

75

74.50 6 12

105

Pressure (bars)

15

90

75° C

76.5

76

77

77.5

3 9

Medium pressure separator pressure

PALANCA separation – output 4th stage

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Pressure (bar)

Output (%)

76.5

76

75.50 10 20 25

4 stages

77.5

77

78

5 15

3 stages

2 stages

PALANCA separation – output T=75°C

significant gain

between 2 & 3

less gain between

3 & 4

�� ECONOMICS

COMPROMISE

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Influence of separation temperature

Temperature + -

Low

Average

High

• Liquid• Economy

• Water

• Gas• H2S treatment

• Gas

Price

EFFECT ON RECOVERY ( )

in general, the lower the T the higher the liquid recovery

(but other parameters interfere on final Process T chosen : e.g. oil/water separation

which is enhanced by high T°C)

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ASHTART

Gas

13b - 110 °C

1b - 85 °C

Gas

Oil

Gas

5b - 40 °C

1b - 35 °C

Gas

Oil

GAIN 9 % OIL at

lower T

Influence of separation T & P : example 1

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BREME

Flare

4b 40° C

1b

Gas

Oil

Flare

4b 40° C

1b

Gas

Oil

GAIN 2.6 % OIL

from flare gas recovery

3.5 b 30° C

Influence of separation T & P : example 2

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3- Separator sizing

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Sizing of a separator

INCREASING COMPLEXITY OF FIELD INSTALLATIONS WITH THE AIM

TO MAXIMISE RECOVEY AND OPTIMISE ALL PRODUCTION UNITS

INTRODUCTION TO GENERAL PRINCIPLES AND METHODS OF SIZING

AND TYPICAL VALUES

SPECIFIC INSTALLATIONS AS HEATER-TREATER, CYCLONIC

SEPARATORS, etc. ARE DETERMINED BY MANUFACTURERS

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DIMENSIONS FOR GAS AND LIQUID FLOWRATES ARE CALCULATED

SEPARATELY

FOR GAS FLOWRATE, SPEED LIMITED TO PREVENT GAS FROM

ENTRAINING DROPLETS OF LIQUID �� smallest diameter possible

FOR LIQUID FLOWRATE, RETENTION TIME �� SIZE TO ENSURE THAT

THE GAS IS COMPLETELY RELEASED FROM IT

DEPENDS ON OIL CHARACTERISTICS

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Basic data


Gas : Flow rate - composition - specific massOil : Flow rate - composition - specific massRetention time

1

Sizing for gas

Sizing = passage cross-sectionPassage cross-section = f (limit velocity gas)Limit velocity gas = liquid not drawn with it

2

Sizing for liquids

Sizing = f (retention time)Retention time = time needed for degassingRetention time = f (oil characteristics)

3

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Vertical separator GAS

Aim : PREVENT WATER BEING DRAWN ALONG

P

T

P =ΠΠΠΠD3

6 Lg

Condition : P > A + R

fixed D limit = 20 µm

A =ΠΠΠΠD3

6VgR = K

ΠΠΠΠD2

4V2

V

V < K D L - VV

1GOR

LV

) = m/sKv = f (

at

D (Ø)L

Liquid

VV (velocity)Gas

A R

P


weight buoyancyaerodynamic force

liquid

max speed not

to carry over D

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Calculation of V (P and T) from M

• Let M = 30 (0° C - 1013 mb)

o =30

22.4Kg/m3 =

MPZRT

• If T = 50° C and P = 20 bar

V = o x PP0

x T0

Tx 1

Z

A few values of Kv

• Flare drum (horizontal) 0.04 m/s• Column head separator (horizontal) 0.07 m/s• Compressor suction (vertical) 0.04 m/s

=30

22.4 x20

1.013 x273323 x

10.93 = 24 kg/m3

Vertical separator GAS


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Separator value of Kv in m/s versus GOR

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Vertical separator LIQUID

Transit time through the vessel

Concerns water and oil (Gas : pm)

T = VQ

= ΠΠΠΠ D2

4x h

Q


T:transit time

T:transit time fonction of decantation time and retention time

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Gas Outlet

GAS

Oil outlet

Water outlet

OIL

WATER

Feed

Water droplet

Gas bubbleOil droplet

VERTICAL Separator / Liquid : liquid sizing

Decantation time refers to liquids

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Decantation time

STOKES' law

D=O.1 mm (around 20 to 30 µm in general)

V =g D2 ( L - V)

18 µµµµ


V = settling velocity of the liquid dropletD = diameter of the dropletL = specific gravity of dropletV = specific gravity of the gas at P&T

g = gravitational accelerationµ = viscosity of the continuous phase

note : Decantation time is very dependant of the crude and water characteristics (�� emulsions)

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Retention time (practical reference)


corresponds to the value obtained by taking the volume measured between the mean level and the low level, where the mean level usually is located in the middle of the drum

Often varies with the crudes from 2" to 5" in most casesbut can reach 10" or even 30" or 60" for "problematic" crude, i.e. heavy oils or acid crudes

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Vertical separator

• Gas passage velocity :

V critical = 0.048 in m/s

Common practices

L - GG

• Internal diameter :D =

D in mQ in m3/hV in m/s

Q

900. ΠΠΠΠ . V• Height of separator :1.5 < Height/Diameter < 3

• Max. oil level :Hoil < 0.65 D

• Low oil level :at 10 inches from the bottom

• Retention timeOil + water = 2" to 5"If foaming or high viscosity : 10"(heavy oil ROSPO MARE : 35")


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Horizontal separator


DemisterFlow straightened cross section

Gas

Liquids

Secondary chamber

Decantation chamber

AR

Pliquid


Gravity Gravity

Vertical separator

Resultant

Entrainment Entrainment

ResultantKv horiz. = 1.25 Kv vertical

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L

l

Vhh

D

Water

h = continuous water height (water)

vh = decantation velocity of an oil droplet (rising)

vwater = displacement velocity of the continuous water phase (horizontal)

l = minimum decantation length

t = decantation time.

Oil droplet Vwater



Decantation time

with Stokes law

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Sizing of a separator: Summary

GAS IS THE PRIORITY PARAMETER TAKEN INTO ACCOUNT IN THE

DESIGN OF SEPARATORS

LIQUID TRANSIT TIME (often referred as Retention time) IS MORE

EMPIRIC AND IS MORE BASED ON EXPERIENCE WITH SAFETY

MARGINS MORE OR LESS IMPORTANT

DECANTATION TIME FOR LIQUIDS IS GENERALLY BASED ON LAB

EXPERIMENTS

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4- Gas/Liquid Separator different types

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Vertical 2 phase separator

Drainage duct

Pressure

valve

Safety seal

Mistextractor

Pressure gauge

Déflector

Oil andgas inlet

Primarychamber

Visuallevel

monitor

Decantationchamber

Base

Purge

Oil outlet

Manhole

Isolation partition

Centrifugal effectin a vertical separator

Gas flowLiquid flow

3

2

1

1. body of separator

2. gas outlet (high point)

3. fluid input

Deflector action

well adapted

for low GOR

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Horizontal 2 phase separator

Mist extractorSettlingsection

Secondarychamber

Primarychamber

Diffuser

Gas + liquidsinlet

Decantationchamber

Separationpartition

Purge

Anti-wavepartition

ChassisOil outlet

Gas

Liquid

Inlet diffuser

Gas

outlet

well adapted

for high GOR

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gas outlet Inlet

liquid outlet

High-pressure horizontal separator with liquid retention capacity

large capacity

high P

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Spherical 2 phase separator

Fluids inlet

Gas outlet

Oil outlet

Level regulation

Scrubber

Deflector

rare

for very high GOR

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Cyclone effect separator

Gas outlet

Gas + Liquid inlet

Liquid outlet

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Multi-cyclone separator

Multi-cyclones

Gas outlet

Liquidoutlet

DiffuserGas inlet

Liquid level Secondary drain

Retention volume

Liquid outlet

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Other typesof gas/liquid separators

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Gas SCRUBBER

Mist extractor

Sifter

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Horizontal 2 phase separator components/internals

Mist extractor

Settling section

Secondarychamber

Primary chamber

Diffuser

Gas + liquids inlet

Decantationchamber Separation

partition

Purge

Anti-wavepartition

Chassis

Oil outlet

Gas

outlet

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Foaming

Origin

• Gas expansion + oil / gas surface tension

• Pure liquids do not foamA surfactant is neededMixtures of isomers in hydrocarbons are surfactants

• Foams are unstable (state of least energy)

• The internal viscosity of the oil stabilises the foam, leading to drawing along of the gas (foaming)

Theory

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– INCONVENIENTS :

• oil entrainments in gas (affecting scrubbers, flares, compressors protection, gas treatment solvents ...), and gas entrainments in oil ( pump cavitation, later degassing...)

• loss of control of levels in separators

FOAMS – Inconvenience

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GAZ

• the speed of drainage is

dependant of the viscosity of

the oil

•the max width is dependant

of the liquid interfacial

tension

INTERFACIAL FILM

FOAMS – Schematic representation

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•• NATURAL SURFACTANTSNATURAL SURFACTANTS

•• ADDED SURFACTANTS (PRODUCTION CHEMICALS)ADDED SURFACTANTS (PRODUCTION CHEMICALS)

•• SOLID PARTICULESSOLID PARTICULES

•• WATER DROPLETSWATER DROPLETS

FOAMS STABILISATION

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Foaming is dependant on crude characteristics

BUT

• If asphaltene content > 1 %, higher foaming and stability

• if acid index >0.2 mg KOH/l, lower quantity of foam & higher stability

• The % of water and additives (anticorrosion etc… ) do not appear to

have any effect on the phenomenon

Tendency to foam

API 40 = .825 API 30 = .876

Increase in % vol.Foam breaking in seconds

API > 40 30 < API < 40 API < 30

10 - 20 20 - 40 > 50

30 30 - 60 > 60

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• THE VERTICAL SPEED OF GAS BUBBLES IS HIGH DUE TO THE

HIGH DENSITY DIFFERENCE WITH THE OIL (STOKES LAW)

• GAS BUBBLES FLOCCULATE AT THE SURFACE AND CREATE A

"MATTRESS"

• COALESCENCE BECOMES THE LIMITING FACTOR

– THE LIQUID IS DRAINED OUT OF THE INTERFACIAL FILM

DECREASING ITS WIDTH UNTIL A MINIMUM VALUE IS REACHED

WHERE IT BREAKS

– BREAKING WIDTHS ARE MUCH THINNER THAN FOR EMULSIONS

FOAMS : separation / breaking

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•• IT IS POSSIBLE TO :IT IS POSSIBLE TO :

–– increase the breaking width of the foam by adding a chemicalincrease the breaking width of the foam by adding a chemical

–– increase the speed of drainage by lowering the liquid increase the speed of drainage by lowering the liquid

viscosity (HEAT)viscosity (HEAT)

–– install separator internals acting on install separator internals acting on wettabilitywettability

–– use separators equipped with specific cyclonic inlet devicesuse separators equipped with specific cyclonic inlet devices

FOAMS TREATMENT

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Treatment

• Mechanical - Washing- longer time spent in installation

• Chemical - anti-foam

FOAMS TREATMENT

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Chemical Treatment

Action:• displace the foam stabilizing element from the bubble walls• or cause bubbles to burst locally

Necessary conditions:• be soluble in the foaming system• disperse satisfactorily• have surface tension < that of the foam

ANTI-FOAMS

FOAMS TREATMENTS : anti-foams

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antianti--foam additivesfoam additives

– MOSTLY USED : SILICONE OILS ( POLYSILOXANES )

– EFFICIENT AT 2/3 ppm (4 to 5 ppm if diluted )

– HAVE TO BE INJECTED UPSTREAM THE SEPARATOR BUT THE

CLOSER FROM THE INLET

• LOSS OF EFFICIENCY AFTER A CERTAIN PERIOD OF TIME)

• LOOSE THEIR EFFICIENCY WHEN TOO MUCH MIXED WITH THE CRUDE

THESE PRODUCTS ARE REFINERY CATALYSTS POISONS

their dosage have to be strictly controlled


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OTHER PRODUCTSOTHER PRODUCTS ::

– Heavy Alcohols, cheap but weak efficiency

– fluoro-Silicones, very efficient but expensive

• to be used in severe cases

�Selection implemented in the Flash Foaming Test (Lab)


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CRUDE OIL FOAMING TENDENCIES

FLASH FOAMING TESTFLASH FOAMING TEST

MPI

TR

TR

OILSTORAGE NITROGEN

BUTANE

TO WATER BATH

CALIBRATED CYLINDER

ADJUSTABLECONTROL VALVE

( 35 L/H)

PROCEDURE

P = 10 BARS with N2 / BUTANE

T = 60 ° C

600 CC OIL

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Gutter separatorfor foam treatment

Diffuser

Oil

Inclinedplates

Inlet

Mist extractor

Gas

FOAMS TREATMENTS : mechanical

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Foam treatmentby heating

in salt water bath

Mist extractor

Inlet

Burner

LC(water)

Water

LC(water)

oil

Gas

Gas

PC (gas)

Oil

Heating

Salt water


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•• FOAMS ARE SIMILAR TO EMULSIONSFOAMS ARE SIMILAR TO EMULSIONS

•• HEAVY OILS (viscous) OR ACID/NAPHTENIC CRUDES HEAVY OILS (viscous) OR ACID/NAPHTENIC CRUDES

(natural surfactants) ARE CREATING STRONG FOAMS(natural surfactants) ARE CREATING STRONG FOAMS

•• IF FOAMING HAS BEEN ANTICIPATED, OVERSIZING IF FOAMING HAS BEEN ANTICIPATED, OVERSIZING

OF SEPARATORS OR SEPARATOR INTERNALS CAN OF SEPARATORS OR SEPARATOR INTERNALS CAN

BE CHOSEN TO LIMIT INCONVENIENTSBE CHOSEN TO LIMIT INCONVENIENTS

•• IF NOT, FOAM TREATMENT USUALLY REQUIRES IF NOT, FOAM TREATMENT USUALLY REQUIRES

HEAT + CHEMICAL TREATMENTHEAT + CHEMICAL TREATMENT

FOAMS - CONCLUSIONS

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Pressure (bars)

300

250

200

150

100

50

00 50 100 150 200

100 %98.497.29694.4

91.7

88.9

85.1

80

T(° C)TG

P1

Bubble curve

88.9 %

Flash liberation

Yield (R)

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Pressure (bars)

300

250

200

150

100

50

00 50 100 150 200

100 %

95.0

88.1

86.2

T(° C)TG

P1

Initial bubble

curve in the

reservoir

83.792 %

Elimination of gas

Bubble curve atperforations

Differential liberation

Yield (R)

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Pressure (bars)

300

250

200

150

100

50

0

0 50 100 150 200

100 %

91.0

88.9

T(° C)TG

P1

Initial bubble

curve in the

reservoir

84.790 % 1st stage separation

gas elimination

Perforations

86.7

Well headBubble curveat perforations

Composite liberation

Yield (R)

1 - crude oil treatment - separation

Documents