SURFACE PROCESSING
A CRUDE OIL TREATMENTI- SEPARATION 2007 ENSPM Formation Industrie - IFP Training
PRO01198 CRUDE OIL TREATMENT - Separation
SEPARATION Contents1- 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 2007 ENSPM Formation Industrie - IFP Training
4- Gas/Liquid Separator different types 5- Foaming (difficult gas/liquid separation) Next course: Oil/Water separationPRO01198 CRUDE OIL TREATMENT - Separation
1- Well head effluents 2007 ENSPM Formation Industrie - IFP Training
PRO01198 CRUDE OIL TREATMENT - Separation
WELL HEAD EFFLUENTS
GAS WELLHEAD EFFLUENTS OIL WATERFORMATION SAND AND SILT COLLOID STATE CLAY CORROSION PRODUCT WAXES ASPHALTENES MINERAL CRYSTALS NaCl CaCO3 BaSO4 SrSO4
2007 ENSPM Formation Industrie - IFP Training
PRO01198 CRUDE OIL TREATMENT - Separation
SEPARATION CHAIN
FOAMSWELLHEAD EFFLUENTS
LIQUID DROPLETS IN GAS
GAS
GAS TREATMENT DEHYDRATION CONDENSATE RECUPERATION
CONDENSATE WATER
GAS-LIQUID SEPARATION
EMULSION INTERMINGLED WATER/OIL
export crudeOIL-WATER SEPARATIONOPERATIONS SOMETIMES CARRIED OUT in 1 PROCESS EQUIPMENTPRO01198 CRUDE OIL TREATMENT - Separation
2007 ENSPM Formation Industrie - IFP Training
EMULSION TREATMENT
EMULSION FREE WATER WATER
SOURCE OF WATER
WATER AND OIL ZONES IN RESERVOIR
OIL OIL 2007 ENSPM Formation Industrie - IFP Training
* Active Water Reservoir * Water Injection : Injection of 1-2 volumes of water Production of 1-5 volumes of water per oil volume * Faulty Cementing JobPRO01198 CRUDE OIL TREATMENT - Separation
SOURCE OF SALTRESERVOIR WATER SALT INJECTED WATER (SEA WATER)
*HASSI MESSAOUD : CAMBRIEN WATER 370g/l Low Water Cut 0,1% HIGH SALT CONTENT SALT CONTENT 370 mg/l
*If Salt Content>10mg/l , Reservoir Water INGRESS *Sometimes HIGH SALT CONTENT without Water EAST BAGDAD As much as 265ppm of salt *** * Same for Hassi Messaoud - Fateh - ABK -Zadco This Phenomenon is limited in Time Produced Water Not Detected; only salt content is measured 2007 ENSPM Formation Industrie - IFP Training
PRO01198 CRUDE OIL TREATMENT - Separation
OIL , BSW and GOR EVOLUTION WITH TIMEProduction3 106 m3 / an
difficulty to design separation equipment
OIL
2
BSW%
GOR 300
30
1
20
200 2007 ENSPM Formation Industrie - IFP Training
10
100
GOR1 2 3 4 5 6 7
BSW8 9 10 11 12
YEARS
PRO01198 CRUDE OIL TREATMENT - Separation
CONTRACTUAL WATER AND SALT CONTENTS
CRUDE OIL MARKETING PRODUCERS TRANSPORTERS REFINERS
$
Business is business!!
$
AGREEMENT
TRANSPORTERS : LIMITATION FOR WATER CONTENT *PIPELINE - PIPE OVER LOADING - CORROSION ( WATER + SALT ) BSW P2
P2 V2 T2 G2 L2 P2 T2
P1 > P2 T1 > T2
2007 ENSPM Formation Industrie - IFP Training
2. Differential processP1 > P2 G1 L1 P1 T1 total composition varies : there is draw off GS Gi Li G2 L2 P2 T2
If T = constant = differential liberation 2007 ENSPM Formation Industrie - IFP Training
PRO01198 CRUDE OIL TREATMENT - Separation
3. Composite process : combination of the twoReservoir PG TG LDifferential Liberation (T cst)
Separators PF TG G LFlash
Storage P2 T2 G2 L2 Pa Ta GS LSFlash
P1 T1 G1 L1Flash
PPG PF
P1 P2 Pa Ta T2 T1 TG
2007 ENSPM Formation Industrie - IFP Training
T
PRO01198 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
2007 ENSPM Formation Industrie - IFP Training
PRO01198 CRUDE OIL TREATMENT - Separation
Influence of the Process Recovery rateP Pb 1 Liberation 1 3 15 RsFROM PVT LAB EXPERIMENTS
Separation 2 TG T
Flash Differential Rs = V gas produced V oil at Pb Pb
2007 ENSPM Formation Industrie - IFP Training
P
PRO01198 CRUDE OIL TREATMENT - Separation
Influence of the Process Recovery rate
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
2007 ENSPM Formation Industrie - IFP Training
PRO01198 CRUDE OIL TREATMENT - Separation
Influence of the process Recovery rateApplication / Field One stage G L Pi T1 Several stages G L P1 T1 G L P2 T1 Separators G L P3 T1 G L Ps T1 Storage G L Ps T1 Flash liberation max gas & min liquid
2007 ENSPM Formation Industrie - IFP Training
in each separator : flash liberation but the whole chain of separators represents a differential separation max of liquid recovery for an infinite number of separation stages
PRO01198 CRUDE OIL TREATMENT - Separation
Separation pressure at the different stagesRule of thumb n-1
R=
P sep. HP P storage
n = number of stages + storage Examples GOR < 20 m3/m3 1 3-7 bara : 2 Storage : 1 :10-20 bara 2 2-6 bara : 3 Storage : GOR > 200 1 20-40 bara : 2 5-15 bara : 2007 ENSPM Formation Industrie - IFP Training
GOR < 150 m3/m3
3 2-5 bara : 4 Storage :
PRO01198 CRUDE OIL TREATMENT - Separation
EXAMPLE OF APPLICATION
PALANCA FIELD (ANGOLA)
Separation efficiency = final stock tank oil mass / mass of hydrocarbonsentering the processing unit
at P = 25, 20, 15 & 10 bar at T = 105 90 75 C, C, C Determination of the optimal P & T and number of separation stages to get the higher separation efficiency
2007 ENSPM Formation Industrie - IFP Training
PRO01198 CRUDE OIL TREATMENT - Separation
PALANCA separation output 2nd stageSep. Efficiency (%) 76.5 76 75.5 75 74.5 74 73.5 2007 ENSPM Formation Industrie - IFP Training
75 C
90
73 72.5 0 5 10 15 20
105
25 Pressure (bars)
PRO01198 CRUDE OIL TREATMENT - Separation
PALANCA separation output 3rd stageSep. Efficiency (%)77.5 77 76.575 C
76 75.5 75 74.5 74 2007 ENSPM Formation Industrie - IFP Training
90
73.5 73 0 3 6 Low pressure separator pressure 9 12
105
15 Pressure (bars)
PRO01198 CRUDE OIL TREATMENT - Separation
PALANCA separation output 4th stageSep. Efficiency (%) 77.575 C
77
76.5
76
90
75.5
75
2007 ENSPM Formation Industrie - IFP Training
74.5 3 0 6 Medium pressure separator pressure 9 12
105
15 Pressure (bars)
PRO01198 CRUDE OIL TREATMENT - Separation
PALANCA separation output T=75 COutput (%) 78
77.54 stages
77
76.5
significant gain between 2 & 3 less gain between 3&43 stages 2007 ENSPM Formation Industrie - IFP Training
76
ECONOMICS COMPROMISE0 5
2 stages
75.5 10 15 20 25 Pressure (bar)
PRO01198 CRUDE OIL TREATMENT - Separation
Influence of separation temperatureEFFECT ON RECOVERY ( )
Temperature Low Average High
+Liquid Economy Water Gas H2S treatment
Gas
Price 2007 ENSPM Formation Industrie - IFP Training
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)PRO01198 CRUDE OIL TREATMENT - Separation
Influence of separation T & P : example 1
ASHTARTGas
13b - 110 C 1b - 85 C
Gas
Oil Gas
5b - 40 C 1b - 35 C
Gas
GAIN 9 % OIL at lower T
Oil
2007 ENSPM Formation Industrie - IFP Training
PRO01198 CRUDE OIL TREATMENT - Separation
Influence of separation T & P : example 2BREMEFlare
4b 40 C 1b
Gas
Oil
Flare
3.5 b 30 C 4b 40 C 1bGas 2007 ENSPM Formation Industrie - IFP Training
Oil
GAIN 2.6 % OIL from flare gas recoveryPRO01198 CRUDE OIL TREATMENT - Separation
3- Separator sizing
2007 ENSPM Formation Industrie - IFP Training
PRO01198 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 2007 ENSPM Formation Industrie - IFP Training
PRO01198 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 2007 ENSPM Formation I
