Electrokinetics of Limestone Particles and Crude-Oil Droplets in Saline Solutions
- Mohammed B. Alotaibi (Texas A&M University) | Hisham A. Nasr-El-Din (Texas A&M University)
- Document ID
- Society of Petroleum Engineers
- SPE Reservoir Evaluation & Engineering
- Publication Date
- October 2011
- Document Type
- Journal Paper
- 604 - 611
- 2011. Society of Petroleum Engineers
- 5.4.1 Waterflooding, 5.2 Reservoir Fluid Dynamics, 5.8.7 Carbonate Reservoir
- Limestone particles, Wettability, Electrokinetics, Zeta potential, Crude oil
- 5 in the last 30 days
- 707 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 12.00|
|SPE Non-Member Price:||USD 35.00|
Salinity adjustment of waterflooding has been applied recently as an enhanced-oil-recovery (EOR) technique in sandstone and carbonate reservoirs. Reaction mechanisms were different because of the variation in rock mineralogy and reservoir characteristics. Interactions between injection water, crude oil, and limestone particles are still ambiguous. Anions in seawater are believed to have altered carbonate surface potential to negative and, thus, created repulsion forces between crude-oil droplets (negatively charged) and a connate-water layer. As a result, rock wettability was altered toward water-wet.
In this paper, the surface potential of crude oil and limestone particles was studied at 50°C. Ionic strength was varied using formation brine (230K ppm), seawater (54K ppm), shallow aquifer water (5K ppm), and fresh water. Cation (Na+, Ca2+, Mg2+) and anion (SO42-) concentrations were tuned individually in seawater also. The influence of H+ and OH- ions on the suspensions? surface potential was investigated by diluting seawater and aquifer water with deionized water at different volume ratios. Two-phase (crude oil in water, limestone particles in water) and three-phase (crude oil, and limestone particles in water) tests were performed at pH 8.
The surface potential of oil droplets was strongly affected by 10 vol% diluted seawater, seawater without divalent ions (Ca2+, Mg2+), and deionized water because of the adsorption of OH- ions at the oil/water (O/W) interface. Sodium sulfate solutions (7,120 ppm) also increased the zeta potential absolute value of oil droplets. The effect of ionic strength on zeta potential was more pronounced in the oil-wet limestone particles than in the intermediate-wet samples. An aqueous layer around crude-oil droplets played a key role in determining droplet charges. Results from this study provide some insights on electrokinetics of limestone particles and oil droplets in different saline solutions. Wettability of the rock and oil recovery are affected directly by the zeta potential of oil droplets and suspensions.
|File Size||487 KB||Number of Pages||8|
Abriola, L.M. and Bradford, S.A. 1998. Experimental Investigations of theEntrapment and Persistence of Organic Liquid Contaminants in the SubsurfaceEnvironment. Environ. Health Perspect. 106 (Supplement 4):1083-1095. http://dx.doi.org/10.2307/3434156.
Alotaibi, M.B., Nasr-El-Din, H.A., and Fletcher, J.J. 2011.Electrokintics of Limestone and Dolomite Rock Particles. SPE Res Eval &Eng. SPE-148701-PA (approved for publication 30 March 2011).
Buckley, J.S. 1994. Chemistry of the Crude Oil/Brine Interface. Paperpresented at the International Symposium on Reservoir Wettability and ItsEffect on Oil Recovery, Laramie, Wyoming, USA, 21-23 September.
Buckley, J.S., Takamura, K., and Morrow, N.R. 1989. Influence ofElectric Surface Charges on the Wetting Properties of Crude Oils. SPE ResEng 4 (3): 332-340. SPE-16964-PA. http://dx.doi.org/10.2118/16964-PA.
Chilingar, G.V. and Yen, T.F. 1993. Some Notes on Wettability and RelativePermeabilities of Carbonate Reservoir Rocks, II. Energy Sources 7 (1): 67-75. http://dx.doi.org/10.1080/00908318308908076.
Chow, R.S. and Takamura, K. 1988. Electrophoretic mobilities of bitumen andconventional crude-in-water emulsions using the laser Doppler apparatus in thepresence of multivalent cations. J. Colloid Interface Sci. 125 (1): 212-225. http://dx.doi.org/10.1016/0021-9797(88)90070-7.
Dickinson, W. 1941. The effect of pH upon the electrophoretic mobility ofemulsions of certain hydrocarbons and aliphatic halides. Trans. FaradaySoc. 37 (1941): 140-148. http://dx.doi.org/10.1039/TF9413700140.
Douglas, H.W. 1943. The electrophoretic behaviour of certain hydrocarbonsand the influence of temperature thereon. Trans. Faraday Soc. 39 (1943): 305-311. http://dx.doi.org/10.1039/TF9433900305.
Erbil, H.Y. 2006. Surface Chemistry of Solid and Liquid Interfaces,Chap. 5, Sec. 5.4, 172-175. Oxford, UK: Blackwell Publishing.
Garrison, S. 2004. The Surface Chemistry of Natural Particles, Sec.1.4, 25-30. New York City: Oxford University Press.
Hall, A.C., Collins, S.H., and Melrose, J.C. 1983. Stability ofAqueous Wetting Films in Athabasca Tar Sands. SPE J. 23(2): 249-258. SPE-10626-PA. http://dx.doi.org/10.2118/10626-PA.
Issacs, E., Chow, R., and Babchin, A. 1998. On the Significance of ReservoirWettability on Extraction and Recovery Processes. Paper No. 1998.021 presentedat the 7th UNITAR Heavy Crude and Tar Sands Conference, Beijing,27-30 October.
Pierre, A., Lamarche, J.M., Mercier, R., Foissy, A., and Persello, J.1990. Calcium as Potential Determining Ion in Aqueous Calcite Suspensions.J. Dispersion Sci. Technol. 11 (6): 611-635. http://dx.doi.org/10.1080/01932699008943286.
Rodríguez, K. and Araujo, M. 2006. Temperature and pressure effects on zetapotential values of reservoir minerals. J. Colloid Interface Sci. 300 (2): 788-794. http://dx.doi.org/10.1016/j.jcis.2006.04.030.
Rodri´guez-Valverde, M.A., Cabrerizo-Vilchez, M.A., Páez-Dueñas, A., andHidalgo-Álvarez, R. 2003. Stability of highly charged particles:bitumen-in-water dispersions. Colloids Surf., A 222 (1-3):233-251. http://dx.doi.org/10.1016/s0927-7757(03)00228-0.
Schramm, L.L. ed. 2000. Surfactants: Fundamentals and Applications in thePetroleum Industry, 30-39. Cambridge, UK: Cambridge University Press.
Schramm, L.L., Mannhardt, K., and Novosad, J.J. 1991. Electrokineticproperties of reservoir rock particles. Colloids Surf. 55:309-331. http://dx.doi.org/10.1016/0166-6622(91)80102-t.
Sjöblom, J. ed. 2006. Emulsions and Emulsion Stability, secondedition, Vol. 132, 456-464. New York City: Surfactant Science Series, Taylorand Francis/CRC Press.
Strand, S., Puntervold, T., and Austad, T. 2008. Effect of Temperatureon Enhanced Oil Recovery from Mixed-Wet Chalk Cores by Spontaneous Imbibitionand Forced Displacement Using Seawater. Energy Fuels 22(5): 3222-3225. http://dx.doi.org/10.1021/ef800244v.
Strand, S., Standnes, D.C., and Austad, T. 2003. SpontaneousImbibition of Aqueous Surfactant Solutions Into Neutral to Oil-Wet CarbonateCores: Effects of Brine Salinity and Composition. Energy Fuels 17 (5): 1133-1144. http://dx.doi.org/10.1021/ef030051s.
Takamura, K. and Chow, R.S. 1985. The electric properties of thebitumen/water interface Part II. Application of the ionizable surface-groupmodel. Colloids Surf. 15: 35-48. http://dx.doi.org/10.1016/0166-6622(85)80053-6.
Toulhoat, H. and Lecourtier, J. ed. 1991. Physical Chemistry of Colloidsand Interfaces in Oil Production, 359-360. Paris: Editions Technip.
Zhang, P., Tweheyo, M.T., and Austad, T. 2007. Wettability alterationand improved oil recovery by spontaneous imbibition of seawater into chalk:Impact of the potential determining ions Ca2+, Mg2+, andSO42-. Colloids Surf., A 301 (1-3):199-208. http://dx.doi.org/10.1016/j.colsurfa.2006.12.058.