Crude Oil Compatibility
Irwin (Irv) WieheSoluble Solutions
COQG Meeting
Houston, TexasOctober 2, 2003
www.SolubleSolutions.com Solubletions
Including Fouling Tendency in Crude OilPurchase Decisions
Irwin (Irv) WieheSoluble Solutions
MUG 36Haverly Technical Conference
Newport, Rhode IslandSeptember 28 to October 1, 2003
www.SolubleSolutions.com Solubletions
Otherwise Optimum Crude Oil BlendsCan Be Fouling Disasters
Soluble Solutions
Incentives to Minimize Fouling
Causes of Asphaltene Fouling
Solution: Oil Compatibility Model & Tests
Services Provided by Soluble Solutions
How to Apply ResultsSoluble
tions
Consulting Projects Teaching
Solubletions
FoulingMitigation
PetroleumCharacterization
Crude OilBlending
Resid Conversion
Soluble Solutions
22 Years at Exxon Corporate Researchand 5 Years at Soluble Solutions
Fouling Common in Crude Preheat Train
StableEmulsions
Heat ExchangerFouling
Atmospheric
Distillation Unit
Coking
Coking
Solubletions
Large Incentives for Minimizing Foulingof Crude Preheat Train
Decreased Maintenance Costs
Reduced Energy Costs
Increased Capacity (Days on Stream)
Confidence to Purchase Opportunity Crudes
First Three: 3 Billion $ / Year for US Refining (C. B. Panchal of Argonne National Labs)
Needs to be Estimated for Each RefinerySoluble
tions
Causes of Crude Preheat Train Fouling
Iron Sulfide / Iron Oxide: Corrosion
Sea Salts & Clays: Desalter Operation (Emulsions)
Asphaltenes: Crude Oil Selection / Blending Order Insoluble: Incompatibility or Self-Incompatibility
Soluble: Nearly Incompatible: Adsorption (Slower)
Solubletions
10 Microns
Physical Model of Petroleum s s s s a a a s s a R R R a ss a R A A R a ss a R A A R a s s a R R R a s s a a a s s s s
Asphaltenes Held in Oil in Delicate Balance Balance Upset by Adding Saturates
Balance Upset by Reducing Aromatics and/or Resins
Mixing Oils Can Upset Balance and Precipitate Asphaltenes: Incompatibility
A = Asphaltenes (Solute)
R = Resins (Dispersant)
a = Aromatics (Solvent)
s = Saturates (Nonsolvent)
Solubletions
s s s s a a a s s a R R R a ss a R A A R a ss a R A A R a s s a R R R a s s a a a s s s s
s s s s a a a s s a R R R a s s a R A A R a s s a R A A R a s s a R R R a s s a a a s s s s
+
s s s s a a a s s a R R R a ss a R A A R a ss a R A A R a s s a R R R a s s a a a s s s s
s s s s a a a s s a R R R a s s a R A A R a s s a R A A R a s s a R R R a s s a a a s s s s
+
s s s
s a a a s
s a R R R a s
s a a R A A R a a s
s a R A A A A R a s
s a R A A A A R a s
s a a R A A R a a s
s a R R R a s
s a a a s
s s s
Deposit
Deposit
Adsorb
Mix
Mix
Self-Incompatible
Incompatible on Blending
Nearly Incompatible
Avoiding Asphaltene Sediments is not Sufficient
Th
erm
al C
onve
rsio
n a
t H
eate
d W
all
Solubletions
Oil Compatibility Model
Measure Solvency and Insolubility of Oils Toluene: Model Solvent n-Heptane: Model Nonsolvent
Predict Compatibility and Incompatibility Proportions of Blend Order of Blending Self-Incompatible
Nearly Incompatible Oils Fouling by Adsorption Stable Oil-Water Emulsions
Solubletions
Oil Compatibility Model
Insolubility Number ≡ INMeasures Degree of Asphaltene Insolubility
Solubility Blending Number ≡ SBN
Measures Ability of Oil to Dissolve Asphaltenes
I. A. Wiehe and R. J. Kennedy, Energy & Fuels, 14, 56 – 63 (2000).
Solubletions
Criterion of Compatibility: SBN > IN
TestLiquid Oil Mix Oil and
Test Liquid
+ =
See if Insoluble ChainAgglomerates of Asphaltenes
Under Optical Microscope
Measurement of IN and SBN
Blend Oil with Test Liquid (Toluene and n-Heptane)
Determine Flocculation Points for Oil / Test Liquid Ratios
Solubletions
0
5
10
15
20
25
30
% T
olue
ne in
Tes
t Liq
uid
35
40
0 20 40 60 80 100
100 Volume Oil / Volume Test Liquid120 140 160
IN = 29.5SBN = (1 + 100/HD) INSBN = (1 + 100/147) 29.5 = 50
Least Square Line: y = 29.5 - 0.200 x ; R = 0.998
Arab Light Crude
Data Verifies Linear RelationCompatibility Numbers Calculated from Intercepts
Solubletions
IN
HD
Oil Compatibility Tests Heptane Dilution Test
Determine maximum ml. of n-heptane that canbe blended with 5 ml. of oil withoutprecipitating asphaltenes.
Toluene Equivalence TestBlend in separate bottles 10 ml. of test liquidand 2 grams of oil. By varying the vol. %toluene mixed with n-heptane in the test liquid,determine the minimum % toluene required tokeep the asphaltenes soluble.
Other Tests for Oils Without Asphaltenes Solubletions
Mixtures of Oils: Compatibility Criterion*
n321
BNnn3BN32BN21BN1BNmix V......VVV
SV......SVSVSVS
++++++++
=
Solubility Blending Number for a Mixture of n Oils
Compatibility Criterion
MixtureinIMaximumIS NmaxNBNmix =>
Order of Mixing is Important Slow Kinetics for Redissolving Requires to Mix in Order that Never Precipitate Asphaltenes (Add Low SBN to High SBN)
* Process for Blending Potentially Incompatible Oils US Patent 5,871,634 (1999), Assigned to Exxon Soluble
tions
Blends of Souedie and Forties
Volume % Forties
0102030405060708090
100
0 10 20 30 40 50 60 70 80 90 100
Forties: SBN = 27, IN = 11
Souedie: SBN = 63, IN = 39 Incompatible Blends
SBN < IN
IN = 39 for Souedie
S
olu
bil
ity
Ble
nd
ing
Nu
mb
er
Incompatible Blends: Volume Average SBN < IN of Any Oil
Solubletions
Self-Incompatible Crude OilSoluble in 1 Volume of Toluene but not n-Heptane
0 10 20 30 40 50 60 70 800
10
20
30V
olu
me
% T
olu
ene
in T
est
Liq
uid
100 X V o lu m e o f O il / V o lu m e o f T est L iq u id
IN = SBN = 13 = TE
100 X Volume of Oil / Volume of Test LiquidV0lu
me
% T
olue
ne in
Tes
t Liq
uid
Yme Crude Oil**Thanks to Statoil for permission to present data
Solubletions
More than 10 Self-Incompatible Crudes (12 < IN < 58)
0
10
20
30
40
50
Hig
her I
nsol
ubili
ty N
umbe
r 60
0 10 20 30 40 50 60Lower Solubility Blending Number
Incompatible Pairs of CrudesCompatible Pairs of Crudes
More Than 100 Incompatible Pairs Of Crudes
Prediction Is Conservative
Solubletions
? �
�
Alcor Hot Liquid Process Simulator*
* Done by G. Dickakian of F.A.C.T. Solubletions
Nearly Incompatible Oils are Moderately Fouling
SBN / IN = 1.4 SBN / IN = 1.0SBN / IN = 1.3
Low Fouling
ModerateFouling
HighFouling
1999 US Patent 5,997,723 by Wiehe & Kennedy, Assigned to Exxon
Solubletions
Fouling
Causes of Stable Water in Oil Emulsionsin Desalters (Rag Layer)
Solubletions
Iron Sulfide : Additives to Make Water Wet
Clays: Additives to Make Water Wet
Naphthenic Acids: Limit TAN of Crude Blends
Asphaltenes: Crude Oil Selection / Blending Order
Insoluble: Incompatibility or Self-Incompatibility
Soluble: Nearly Incompatible - Most Stable
% Toluene in Heptane – Toluene(Solubility Blending Number)
% W
ater
Res
olve
dAsphaltene – Toluene - Heptane - Water Mixtures
Emulsions Most Stable by Nearly Incompatible AsphaltenesSt
abili
ty o
f Em
ulsi
on
Solubletions
Water DropletsStabilized byRigid Interface ofAsphaltenes
Mclean andKilpatrick (1997)
Water
Emulsion
Oil
Resolved
e
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Services Offered by Soluble Solutions
Train Your Lab to Run Oil Compatibility Tests
Run Tests at DNV Petroleum Services, NJ ($500 per Crude Oil)
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Companies Pool Results and Cost of Running Tests
Best Results at Lowest Price
Solubletions
Advise on Crude Purchasing, Scheduling, Blending Decisions with Respect to Fouling
How to Apply Without Violating Patents
Do Not Purchase Self-Incompatible Crudes
Do Not Blend Crude Oils that Are Predicted to beIncompatible in Any Proportion
Do Not Blend Crude Oils that Are Predicted to be Nearly Incompatible in Any Proportion
Soluble Solutions Available for Consulting
Solubletions