Crude Oil Treatment Separation

Embed Size (px)

Citation preview

  • 7/22/2019 Crude Oil Treatment Separation

    1/85

  • 7/22/2019 Crude Oil Treatment Separation

    2/85

  • 7/22/2019 Crude Oil Treatment Separation

    3/85

    20

    07

    ENSPMFormationIndustrie-

    IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    1- Well head effluents

  • 7/22/2019 Crude Oil Treatment Separation

    4/85

    20

    07

    ENSPMFormationIndustrie-

    IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    WELL HEAD EFFLUENTS

    WELLHEADWELLHEADEFFLUENTSEFFLUENTS

    GASGAS

    OILOIL

    WATERWATER

    FORMATION SAND AND SILTFORMATION SAND AND SILT

    COLLOID STATE CLAYCOLLOID STATE CLAY

    CORROSION PRODUCTCORROSION PRODUCT

    WAXESWAXES

    ASPHALTENESASPHALTENESMINERAL CRYSTALSMINERAL CRYSTALS

    NaClNaCl CaCO3 BaSO4 SrSO4CaCO3 BaSO4 SrSO4

  • 7/22/2019 Crude Oil Treatment Separation

    5/85

    20

    07

    ENSPMFormationIndustrie-

    IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    SEPARATION CHAIN

    EMULSIONEMULSION

    INTERMINGLED WATER/OILINTERMINGLED WATER/OIL

    FOAMSFOAMSLIQUID DROPLETSLIQUID DROPLETS

    IN GASIN GASWELLHEAD EFFLUENTSWELLHEAD EFFLUENTS

    CONDENSATECONDENSATE

    FREE WATERFREE WATER

    GASGAS--LIQUIDLIQUID

    SEPARATIONSEPARATION

    GAS TREATMENTGAS TREATMENT

    DEHYDRATIONDEHYDRATION

    CONDENSATECONDENSATE

    RECUPERATIONRECUPERATION

    EMULSIONEMULSIONTREATMENTTREATMENT

    WATERWATER

    EMULSIONEMULSION

    GASGAS

    WATERWATER

    OPERATIONS SOMETIMESOPERATIONS SOMETIMESCARRIED OUTCARRIED OUT

    in 1 PROCESS EQUIPMENTin 1 PROCESS EQUIPMENT

    export

    crude

    OILOIL--WATERWATERSEPARATIONSEPARATION

  • 7/22/2019 Crude Oil Treatment Separation

    6/85

    20

    07

    ENSPMFormationIndustrie-

    IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    SOURCE OF WATER

    WATER AND OIL ZONES IN RESERVOIRWATER 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

  • 7/22/2019 Crude Oil Treatment Separation

    7/85

    20

    07

    ENSPMFormationIndustrie-

    IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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 measuredProduced 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 -Zadco

    This Phenomenon is limited in Time

  • 7/22/2019 Crude Oil Treatment Separation

    8/85

    20

    07

    ENSPMFormationIndustrie-

    IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    9/85

    20

    07ENSPMFormationIndustrie-

    IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    CONTRACTUAL WATER AND SALT CONTENTS

    TRANSPORTERSTRANSPORTERS : LIMITATION FOR WATER CONTENT: LIMITATION FOR WATER CONTENT

    *PIPELINE*PIPELINE -- PIPE OVER LOADINGPIPE OVER LOADING

    BSW

  • 7/22/2019 Crude Oil Treatment Separation

    10/85

    2007ENSPMFormationIndustrie-

    IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    1 ELECTROSTATIC DESALTER1 ELECTROSTATIC DESALTER SALT CONTENT

  • 7/22/2019 Crude Oil Treatment Separation

    11/85

    2007ENSPMFormationIndustrie-

    IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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 SETPREVIOUSLY WITH WASH WATER SOFTERTHAN RESERVOIR WATER

    DEHYDRATION/DESALTING

  • 7/22/2019 Crude Oil Treatment Separation

    12/85

    2007ENSPMFormationIndustrie-

    IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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.

  • 7/22/2019 Crude Oil Treatment Separation

    13/85

    2007ENSPMFormationIndustrie-

    IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    2- Gas/liquid separation

  • 7/22/2019 Crude Oil Treatment Separation

    14/85

    2007ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    15/85

    2007ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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)

  • 7/22/2019 Crude Oil Treatment Separation

    16/85

    200

    7ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    17/85

    200

    7ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Phase diagram

    P

    Liquid

    Pr

    Vapour

    T0

    Pf

    0 %

    100 %

    Ps

    Pc

    Pw

    Bubble Point

    mole % liquid

    30 %

    15 %5 %

    1 %

  • 7/22/2019 Crude Oil Treatment Separation

    18/85

    200

    7ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    METHANE - ETHANE MIXTURE PHASE DIAGRAM

  • 7/22/2019 Crude Oil Treatment Separation

    19/85

    200

    7ENSPMFormationIndustrie-I

    FPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    GAS PHASE ENVELOPPE SHAPE VERSUS GAS COMPOSITION

  • 7/22/2019 Crude Oil Treatment Separation

    20/85

    200

    7ENSPMFormationIndustrie-I

    FPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    at Constant composition

    1. Flash process

    If T constant = flash liberation

    P1 V1T1

    P2 V2T2

    with P1 > P2

    P1 V1

    T1

    P2 V2

    T1

    P1 > P2

    P1 V1

    T1

    P2 V2

    T2

    P1 > P2T1 > T2

    If T varies = flash separation

    G1L1

    P1 T1

    G2L2

    P2 T2

  • 7/22/2019 Crude Oil Treatment Separation

    21/85

    200

    7ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    total composition varies : there is draw off

    2. Differential process

    If T = constant = differential liberation

    P1 > P2

    G1

    L1

    G2

    L2

    Gi

    Li

    GS

    P1 T1 P2 T2

  • 7/22/2019 Crude Oil Treatment Separation

    22/85

    200

    7ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    3. Composite process : combination of the two

    GLL G1L1 L2 GSLSG2

    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

  • 7/22/2019 Crude Oil Treatment Separation

    23/85

    200

    7ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    24/85

    200

    7ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    25/85

    2007

    ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    QUANTITIES OF FREE GAS ARE MORE IMPORTANT IN FLASH

    LIBERATION THAN IN DIFFERENTIAL LIBERATION

    SIMILARLY, VOLUME OF LIQUID IS GREATER IN A DIFFERENTIALPROCESS 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

  • 7/22/2019 Crude Oil Treatment Separation

    26/85

    2007

    ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    27/85

    2007

    ENSPMFormationIndustrie-IF

    PTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    28/85

    2007

    ENSPMFormationIndustrie-IF

    PTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    PALANCA FIELD (ANGOLA)

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

    entering the processing unit

    at P = 25, 20, 15 & 10 barat T = 105C, 90C, 75C

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

    higher separation efficiency

    EXAMPLE OF APPLICATION

  • 7/22/2019 Crude Oil Treatment Separation

    29/85

    2007

    ENSPMFormationIndustrie-IF

    PTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    30/85

    2007

    ENSPMFormationIndustrie-IF

    PTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    31/85

    2007

    ENSPMFormationIndustrie-IF

    PTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    32/85

    2007

    ENSPMFormationIndustrie-IF

    PTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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=75C

    significant gainbetween 2 & 3

    less gain between

    3 & 4

    ECONOMICS

    COMPROMISE

  • 7/22/2019 Crude Oil Treatment Separation

    33/85

    2007

    ENSPMFormationIndustrie-IF

    PTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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 TC)

  • 7/22/2019 Crude Oil Treatment Separation

    34/85

    2007

    ENSPMFormationIndustrie-IF

    PTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    ASHTART

    Gas

    13b - 110 C

    1b - 85 C

    Gas

    Oil

    Gas

    5b - 40 C

    1b - 35 C

    Gas

    Oil

    GAIN 9 % OIL atlower T

    Influence of separation T & P : example 1

  • 7/22/2019 Crude Oil Treatment Separation

    35/85

    2007

    ENSPMFormationIndustrie-IF

    PTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    36/85

    2007

    ENSPMFormationIndustrie-IF

    PTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    3- Separator sizing

  • 7/22/2019 Crude Oil Treatment Separation

    37/85

    2007

    ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    38/85

    2007

    ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Sizing of a separator

    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

    Si i f

  • 7/22/2019 Crude Oil Treatment Separation

    39/85

    2007

    ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Basic data

    Sizing of a separator

    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

    Si i f t

  • 7/22/2019 Crude Oil Treatment Separation

    40/85

    2007

    ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Vertical separator GAS

    Aim : PREVENT WATER BEING DRAWN ALONG

    P

    T

    P =

    D3

    6 Lg

    Condition : P > A + R

    fixed D limit = 20 m

    A =

    D3

    6 Vg

    R = K

    D2

    4 V2

    V

    V < K DL - V

    V

    1GOR

    LV

    ) = m/sKv = f (

    at

    D ()

    LLiquid

    VV (velocity)Gas

    A R

    P

    Sizing of a separator

    weight buoyancyaerodynamic force

    liquid

    max speed not

    to carry over D

    Si i f t

  • 7/22/2019 Crude Oil Treatment Separation

    41/85

    2007

    ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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 T0T

    x 1Z

    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

    Sizing of a separator

    Separator al e of K in m/s ers s GOR

  • 7/22/2019 Crude Oil Treatment Separation

    42/85

    2007

    ENSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Separator value of Kv in m/s versus GOR

    Sizing of a separator

  • 7/22/2019 Crude Oil Treatment Separation

    43/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Vertical separator LIQUID

    Transit time through the vessel

    Concerns water and oil (Gas : pm)

    T = VQ

    = D2

    4x h

    Q

    Sizing of a separator

    T:transit time

    T:transit time fonction of decantation time and retention time

    VERTICAL Separator / Liquid : liquid sizing

  • 7/22/2019 Crude Oil Treatment Separation

    44/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

    Sizing of a separator

  • 7/22/2019 Crude Oil Treatment Separation

    45/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Vertical separator LIQUID

    Decantation time

    STOKES' law

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

    V =g D2 ( L - V)

    18

    Sizing of a separator

    V = settling velocity of the liquid dropletD = diameter of the dropletL = specific gravity of dropletV = specific gravity of the gas at P&Tg = gravitational acceleration = viscosity of the continuous phase

    note : Decantation time is very dependant of the crude andwater characteristics ( emulsions)

    Sizing of a separator

  • 7/22/2019 Crude Oil Treatment Separation

    46/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Vertical separator LIQUID

    Retention time (practical reference)

    Sizing of a separator

    corresponds to the value obtained by taking the volumemeasured between the mean level and the low level, where themean 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

    Sizing of a separator

  • 7/22/2019 Crude Oil Treatment Separation

    47/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

    Q900. . 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")

    Sizing of a separator

    Sizing of a separator

  • 7/22/2019 Crude Oil Treatment Separation

    48/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Horizontal separator

    Sizing of a separator

    DemisterFlow straightened cross section

    Gas

    Liquids

    Secondary chamber

    Decantation chamber

    AR

    Pliquid

    Horizontal separator

    Gravity Gravity

    Vertical separator

    Resultant

    Entrainment Entrainment

    ResultantKv horiz. = 1.25 Kv vertical

    Sizing of a separator

  • 7/22/2019 Crude Oil Treatment Separation

    49/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

    Horizontal separator

    Sizing of a separator

    Decantation time

    with Stokes law

    Sizing of a separator: Summary

  • 7/22/2019 Crude Oil Treatment Separation

    50/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    51/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    4- Gas/Liquid Separatordifferent types

    Vertical 2 phase separator

  • 7/22/2019 Crude Oil Treatment Separation

    52/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    p p

    Drainage duct

    Pressure

    valve

    Safety seal

    Mistextractor

    Pressuregauge

    Dflector

    Oil andgas inlet

    Primarychamber

    Visuallevel

    monitor

    Decantationchamber

    Base

    Purge

    Oil outlet

    Manhole

    Isolationpartition

    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

  • 7/22/2019 Crude Oil Treatment Separation

    53/85

    High-pressure horizontal separator with liquid retention capacity

  • 7/22/2019 Crude Oil Treatment Separation

    54/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    gas outlet Inlet

    liquid outlet

    large capacity

    high P

    Spherical 2 phase separator

  • 7/22/2019 Crude Oil Treatment Separation

    55/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Fluids inlet

    Gas outlet

    Oil outlet

    Level regulation

    Scrubber

    Deflector

    rare

    for very high GOR

    Cyclone effect separator

  • 7/22/2019 Crude Oil Treatment Separation

    56/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Gas outlet

    Gas + Liquid inlet

    Liquid outlet

    Multi-cyclone separator

  • 7/22/2019 Crude Oil Treatment Separation

    57/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Multi-cyclones

    Gasoutlet

    Liquidoutlet

    DiffuserGasinlet

    Liquid level Secondary drain

    Retentionvolume

    Liquidoutlet

  • 7/22/2019 Crude Oil Treatment Separation

    58/85

    Gas SCRUBBER

  • 7/22/2019 Crude Oil Treatment Separation

    59/85

    2007

    ENSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Mist extractor

    Sifter

    VAPE SORBER

  • 7/22/2019 Crude Oil Treatment Separation

    60/85

    2007

    E

    NSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Absorbentmaterial

    Porous filters

  • 7/22/2019 Crude Oil Treatment Separation

    61/85

    2007

    E

    NSPMFormationIndustrie-IFP

    TrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Componentsof a gas/liquid separator

    Horizontal 2 phase separator components/internals

  • 7/22/2019 Crude Oil Treatment Separation

    62/85

    2007

    E

    NSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Mist extractor

    Settling section

    Secondarychamber

    Primary chamber

    Diffuser

    Gas + liquids inlet

    Decantationchamber Separation

    partition

    Purge

    Anti-wavepartition

    Chassis

    Oil outlet

    Gas

    outlet

  • 7/22/2019 Crude Oil Treatment Separation

    63/85

    2007

    E

    NSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    5- Foamingdifficult gas/liquid separation

    Foaming

  • 7/22/2019 Crude Oil Treatment Separation

    64/85

    2007

    E

    NSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    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 drawingalong of the gas (foaming)

    Theory

    FOAMS

  • 7/22/2019 Crude Oil Treatment Separation

    65/85

    2007

    E

    NSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    FOAMS are oil + gas "emulsions"

    T=15mn

    FOAMS Inconvenience

  • 7/22/2019 Crude Oil Treatment Separation

    66/85

    2007

    E

    NSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    INCONVENIENTS :

    oil entrainments in gas (affecting scrubbers, flares,compressors protection, gas treatment solvents ...),

    and gas entrainments in oil ( pump cavitation, laterdegassing...)

    loss of control of levels in separators

    FOAMS Schematic representation

  • 7/22/2019 Crude Oil Treatment Separation

    67/85

    2007

    E

    NSPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    GAZ

    the speed of drainage is

    dependant of the viscosity of

    the oil

    the max width is dependantof the liquid interfacial

    tension

    INTERFACIAL FILM

    FOAMS STABILISATION

  • 7/22/2019 Crude Oil Treatment Separation

    68/85

    2007

    E

    NSPMFormationIndustrie-IFPT

    rainingPRO01198 CRUDE OIL TREATMENT - Separation

    NATURAL SURFACTANTSNATURAL SURFACTANTS

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

    SOLID PARTICULESSOLID PARTICULES

    WATER DROPLETSWATER DROPLETS

    Foaming is dependant on crude characteristics

  • 7/22/2019 Crude Oil Treatment Separation

    69/85

    2007

    E

    NSPMFormationIndustrie-IFPT

    rainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

    FOAMS : separation / breaking

  • 7/22/2019 Crude Oil Treatment Separation

    70/85

    2007

    E

    NSPMFormationIndustrie-IFPT

    rainingPRO01198 CRUDE OIL TREATMENT - Separation

    THE VERTICAL SPEED OF GAS BUBBLES IS HIGH DUE TO THEHIGH 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 FILMDECREASING ITS WIDTH UNTIL A MINIMUM VALUE IS REACHED

    WHERE IT BREAKS

    BREAKING WIDTHS ARE MUCH THINNER THAN FOR EMULSIONS

    FOAMS TREATMENT

  • 7/22/2019 Crude Oil Treatment Separation

    71/85

    2007

    E

    NSPMFormationIndustrie-IFPT

    rainingPRO01198 CRUDE OIL TREATMENT - Separation

    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 liquidincrease the speed of drainage by lowering the liquid

    viscosity (HEAT)viscosity (HEAT)

    install separator internals acting oninstall separator internals acting on wettabilitywettability

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

    FOAMS TREATMENT

  • 7/22/2019 Crude Oil Treatment Separation

    72/85

    2007

    E

    NSPMFormationIndustrie-IFPT

    rainingPRO01198 CRUDE OIL TREATMENT - Separation

    Treatment

    Mechanical - Washing- longer time spent in installation

    Chemical - anti-foam

    FOAMS TREATMENTS : anti-foams

  • 7/22/2019 Crude Oil Treatment Separation

    73/85

    2007

    ENSPMFormationIndustrie-IFPT

    rainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

  • 7/22/2019 Crude Oil Treatment Separation

    74/85

    2007

    ENSPMFormationIndustrie-IFPT

    rainingPRO01198 CRUDE OIL TREATMENT - Separation

    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 POISONStheir dosage have to be strictly controlled

    FOAMS TREATMENTS : anti-foams

  • 7/22/2019 Crude Oil Treatment Separation

    75/85

    2007

    ENSPMFormationIndustrie-IFPT

    rainingPRO01198 CRUDE OIL TREATMENT - Separation

    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)

    CRUDE OIL FOAMING TENDENCIES

  • 7/22/2019 Crude Oil Treatment Separation

    76/85

    2007

    ENSPMFormationIndustrie-IFPT

    rainingPRO01198 CRUDE OIL TREATMENT - Separation

    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

    FOAMS TREATMENTS : mechanical

  • 7/22/2019 Crude Oil Treatment Separation

    77/85

    2007

    ENSPMFormationIndustrie-IFPT

    rainingPRO01198 CRUDE OIL TREATMENT - Separation

    Gutter separatorfor foam treatment

    Diffuser

    Oil

    Inclinedplates

    Inlet

    Mist extractor

    Gas

  • 7/22/2019 Crude Oil Treatment Separation

    78/85

    FOAMS TREATMENTS : mechanical

  • 7/22/2019 Crude Oil Treatment Separation

    79/85

    2007

    EN

    SPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Section X-X

    DIXON PLATES

    FOAMS TREATMENTS : mechanical

  • 7/22/2019 Crude Oil Treatment Separation

    80/85

    2007

    EN

    SPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Foam treatmentby heatingin salt water bath

    Mist extractor

    Inlet

    Burner

    LC(water)

    Water

    LC(water)

    oil

    Gas

    Gas

    PC (gas)

    Oil

    Heating

    Saltwater

    FOAMS - CONCLUSIONS

  • 7/22/2019 Crude Oil Treatment Separation

    81/85

    2007

    EN

    SPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    FOAMS ARE SIMILAR TO EMULSIONSFOAMS ARE SIMILAR TO EMULSIONS

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

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

    IF FOAMING HAS BEEN ANTICIPATED, OVERSIZINGIF FOAMING HAS BEEN ANTICIPATED, OVERSIZING

    OF SEPARATORS OR SEPARATOR INTERNALS CANOF SEPARATORS OR SEPARATOR INTERNALS CAN

    BE CHOSEN TO LIMIT INCONVENIENTSBE CHOSEN TO LIMIT INCONVENIENTS

    IF NOT, FOAM TREATMENT USUALLY REQUIRESIF NOT, FOAM TREATMENT USUALLY REQUIRES

    HEAT + CHEMICAL TREATMENTHEAT + CHEMICAL TREATMENT

    CRUDE OIL PROCESSING - SEPARATION

  • 7/22/2019 Crude Oil Treatment Separation

    82/85

    2007

    EN

    SPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Flash liberation

  • 7/22/2019 Crude Oil Treatment Separation

    83/85

    2007

    EN

    SPMFormationIndustrie-IFPTrainingPRO01198 CRUDE OIL TREATMENT - Separation

    Pressure (bars)300

    250

    200

    150

    100

    50

    00 50 100 150 200

    100 %98.4

    97.29694.4

    91.7

    88.9

    85.1

    80

    T( C)TG

    P1

    Bubble curve

    88.9 %

    Yield (R)

    Differential liberation

  • 7/22/2019 Crude Oil Treatment Separation

    84/85

    2007

    EN

    SPMFormationIndustrie-IFPTr

    ainingPRO01198 CRUDE OIL TREATMENT - Separation

    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 thereservoir

    83.792 %

    Elimination of gas

    Bubble curve atperforations

    Yield (R)

    Composite liberation

  • 7/22/2019 Crude Oil Treatment Separation

    85/85

    2007

    EN

    SPMFormationIndustrie-IFPTr

    ainingPRO01198 CRUDE OIL TREATMENT - Separation

    Pressure (bars)

    300

    250

    200

    150

    100

    50

    0

    0 50 100 150 200

    100 %

    91.088.9

    T( C)TG

    P1

    Initial bubble

    curve in the

    reservoir

    84.790 % 1st stage separation

    gas elimination

    Perforations

    86.7

    Well headBubble curveat perforations

    Yield (R)