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Presentation at the SPE SAS Annual Technical Symposium & Exhibition, AlKhobar, Saudi Arabia
Citation preview
Synthesis and Performance Evaluation of Date Pit Based Surfactant-Polymer Formulation
for Enhanced Chemical Flooding
Jimoh K. Adewole and Abdullah S. Sultan
Center for Petroleum & Minerals, King Fahd University of Petroleum & Minerals,
Dhahran 31261, Saudi Arabia
Outlines
• Introduction• Date Pit Polymers
• Objective
• Experimental Procedure
• Results and Discussion
• Conclusion
• Challenges and Future Works
• Acknowledgement
•an established method employed to prolong the life of an oil well and obtain the maximum recoverable amount of oil from a reservoir •Oil recovery methods are generally subdivided into three stages - primary, secondary and tertiary recovery•About two-third of OOIP is left in the ground after exhausting primary and secondary recovery techniques•This large amount of oil can be recovered using EOR techniques.
Enhanced Oil Recovery (EOR)
Classes of EOR Methods• Thermal (tEOR)
• Chemical (cEOR)
• Gas (gEOR)
Chemical EOR Methods (cEOR)
Individual Injection:
Alkaline
Surfactant
Polymer
Combine Injection:
Surfactant-Polymer (SP) flooding
Alkaline-Surfactant Flooding
Alkaline-Surfactant – Polymer Flooding (ASP)
Major Challenges of cEOR
Cost effectiveness
Cost sensitivity of surfactants and polymers to oil prices
Date Pit Polymers
Saudi Arabia was ranked among the top ten date producing countries in the world
4th largest producer in 2001 (13.3% of global production)
3rd largest producer in 2007
Huge by product from date processing?
Date Pit Polymers Cont’d
500550600650700750800850900950
1990 1995 2000 2005 2010Prod
uctio
n (t
hous
ands
tonn
es)
Year
Fig. 1 Date Production in the Kingdom of Saudi Arabia between 1990 and 2007 (Botes and Zaid, 2002)
Date Pit Polymers Cont’d
Fig. 2 Molecular Structure of Cellulose
Fig. 3 Molecular Structure of Lignin
Fig. 4 Molecular Structure of Hemicellulose
Objective
Investigate the potential of locally available non-petrochemical raw materials for applications in EOR
Specifically, this research work explores the use of local date pits in formulating a surfactant polymer system
Fatty oils from date pit for surfactant (more expensive than the already existing surfactants due to its % composition)
Successful production of polymer from date can facilitate the synthesis of carbohydrate based surfactants which is another area of focus in this project
Oil Content in Seeds
Table 1. Oil Content of Various Types of Seeds Seeds Oil Content (wt%) Africa crabwood 48.00 – 61.5
Castor 35.55
Coconut 64.00
Cotton 15.25
Date pit 5.02 - 12.67
Groundnut 38.50
Jatropha 37.51-35.55
Linseed 35.44
Melon 39.91
Neem 42.45-51.60
Niger 38.50
Palm kernel nut 46.57
Rape/mustard 40.45
Sesame 35.50
Shear nut 34.44
Sunflower 25.40
Average Composition of Date Seeds
Table 2. Average Composition of Date Seeds
Components Contents (%) Moisture 10.20
Ash 1.18
Carbohydrate 72.59 - 86.89,
Crude Proteins 5.67
Fat Contents 5.02 - 12.67
Crude Fiber Content of Date Pit
Table 3 Chemical Composition of Date Pit Fibreous Fraction
Component Molecular Formula Composition (Wt%)
Hemicellulose (C5H8O4)n and (C6H10O5)n 23.3 - 55.5
Lignin C9H10O2, C10H12O3, C11H14O4 14.7 - 23.2
Cellulose C6H10O5 20.18 – 56.7
Ash - 1.1 – 5.3
Experimental Material
Date pit collected from Al Hassa, Saudi Arabia.
Alfoterra ® 123-8S 90 from Sasol, North America Inc
NaOH (Merck)
Distilled water
Experimental Procedure
Date Pit Processing
Soaking of date pits in water
Washing by sonication
Sun drying for 10 days between 38 to 45.5oC
Grinding to powder
De-oiling using hexane in a Soxhlet apparatus
Synthesis of Date Pit Polymer
Mixed solution of NaOH in H2O
Immersion of the de-oiled powder in alkaline solution
Agitation with a Multi-Wrist shaker
Preparation of surfactant-polymer formulation
•date pit polymer mixed with 2wt% Alfoterra
Solubility Test and Calculation
Filtration and and washing with distilled water
Isolation of undissolved fractions
Drying in vacuum oven at 85oC and for about three days
Solubility calculation
1
1max 4.29 WW
WWC
o
o
oW is the initial weight in g and 1W is the weight of undissoled date pit
Solubility Test and Calculation Cont’d
Yield calculation
oo M
M1
oM is the mass of the initial dry date pits
M is the mass of the residue obtained after the reaction.
Viscosity measurement
Measurement was done using Contraves Low-Shear 30 viscometer
Brookfield EX-200 temperature control system
Thermal equilibrium was ensured
Aging also performed
Results and Discussion
Effect of Date Pit Concentration on solubility
0.0
1.0
2.0
3.0
4.0
0.0 1.0 2.0 3.0 4.0Sat
ura
ted S
olu
bil
ity (w
t%)
Weight of Date Pit Powder in Alkaline Solution (g)
Fig. 1 Solubility as a function of Date Pit
maximum value at ~2gcarbohydrate fractioncellulose is dispersionNaOH- hydrates (NaOH.nH2O) formation
Fig. 5 Solubility as a function of Date Pit
Effect of Date Pit Concentration on solubility Cont’d
01020304050607080
0.0 1.0 2.0 3.0 4.0
Yie
ld (%
)
Weight of Date Pit Powder (g)
Fig. 1 Changes in yield with date pit powder reacted with NaOH solution
Yield is between 70 and 57% for date pit weight up to ~2g
Fig. 6 Changes in yield with date pit powder reacted with NaOH solution
Effect of the presence of other componentsHemicellulose interaction with cellulose through hydrogen and covalent bonds (Wang, 2008)Its strong tendency to be deposited on the surface of cellulose fibers reduces it accessibility to the solvents
Viscosity Enhancement Capability
Fig. 7 Viscosity as a function of Concentration of date pit powder at 38oC
Viscosity increment from 0.95cp (for the 2wt% surfactant solution) to about 6cp by addition of 25.76wt% of DPP sampleContinuous increase due to absence of chemical interaction
0
5
10
15
20
25
0.0 2.0 4.0 6.0 8.0 10.0
Visc
osity
(cp)
Weight % Date Pit Powder
Viscosity Enhancement Capability
Fig. 8 Viscosity of surfactant-polymer formulation as a function of DPP concentration, in 2wt% Alfoterra 123-8S-90 at 38oC
The broken line added to predict the viscosity behaviour beyond the experimental values
0123456789
10
0 10 20 30 40
Vis
cosi
ty (cp
)
Concentration of DPP Solution (wt%)
Effect of Temperature of Date Pit Polymer Solution
Fig. 9 Change in Date Pit Polymer Solution Viscosity with Temperature (without Sealing the Surface with Mineral Oil)
incredible pseudo increment in viscosity with increase in temperature
2.02.53.03.54.04.55.0
35.0 45.0 55.0 65.0
Vis
cosi
ty (c
p)
Temperature (oC)
Effect of Temperature of Date Pit Polymer Solution
Fig. 10 Change in Date Pit Polymer Solution Viscosity with Temperature (After Sealing the Surface with Mineral Oil)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
30.0 50.0 70.0 90.0 110.0 130.0
Vis
cosi
ty (c
p)
Temperature (oC)
Day 1
Day 2
Investigation into the effect of temperature on the viscosity with sample covered at the surface using minerals oil.Attempt to test measurement repeatability (Day 1 and Day 2)
Effect of Temperature of Date Pit Polymer Solution
Fig. 11 Viscosity of the DPP solution and aging
Effect of aging time on viscosity at 80oCCovering with oil can only be sustained for more than three daysDue to evaporation of both the mineral oil and the DPP solvent
0.0
0.5
1.0
1.5
2.0
2.5
Day 1 Day 2 Day 3 Day 4 Morning
Day 4 Noon
Day 5
Vis
cosi
ty (c
p)
Time (days)
Conclusion
• Date pit powder can be formulated into a polymer with a potential viscosifying power that can be employed in EOR processes
• Maximum yield of 69% was obtained with NaOH solution which limits the viscosifying power to ~22cp
• The synthesized DPP solution may be applied only to recovery of light crude with viscosity lower than 22cp
• It can also be used as blend with other high viscosity polymer to improve their performance
Challenges and Future Works
non availability of better solvent for higher solubility of date pit powder
Challenges
Future Works
• Investigation of other chemical modification routes to obtain date pit polymer with higher viscosity
• synthesis of carbohydrate based surfactant from date • study of the synergy between date pit polymer and carbohydrate
based surfactant and surfactant from other seeds
Acknowledgement
Center for Petroleum & Minerals, KFUPM
Mr Sulaiman H. Al-Hulaili
Mr Ahmad Adewunmi
Mr Abdulrahim Muhammadain
Mr. Abdulsamad Iddrisu
Thank you