Associative polymers recently tested for their EOR potential in water-wet systems displayed a good potential for reducing residual oil saturation in polymer-flooded cores. In this work, an oil-wet porous medium was used to investigate these observations. A low molecular weight associative polymer was tested as a displacing agent and its ability to increase oil recovery on chemically treated oil-wet Berea cores was evaluated. Linear coreflood experiments were performed using filtered associative polymer solution as the EOR agent at standard pressure and 60°C temperature.

Results from the polymer floods conducted at an established waterflood residual oil saturation (Sorw) yielded increased oil recoveries, i.e., reduced residual oil saturations, Sor, in the formation. The observed incremental oil production was a function of the injected associative polymer treatment volume; Sor decreased with increased injected associative polymer volume. It should be noted that at laboratory conditions it is often hard to establish and also distinguish a 100% water-cut; in other words, true residual oil saturation, Sorw, is often difficult to be established during water injection.

Oil production profile can be discussed based on fractional flow theory, which defines the true Sorw at 100% water-cut. Whenever the produced water-cut is not precisely 100%, oil saturation in the formation is higher than the true Sorw; polymer injection with an improved mobility ratio compared to the water injection one results in an additional oil production, which could be misinterpreted as a reduction in the residual oil saturation, i.e., enhance oil production. Although this accelerated oil production is an attractive possibility (mobility control), it is not an EOR process. Our results are in agreement with previously reported observations in water-wet media related to the EOR nature of the injected associative polymer as opposed to the traditional mobility control of other, either synthetic or organic, polymers. The same results showed that the polymer mobility reduction is highly affected by the injected polymer velocity at the lower spectrum of velocity values and a correlation for the velocity dependent mobility reduction was developed.

Finally, during the injection of the associative polymer, a column of oil-polymer emulsion was formed gradually in the separator which caused some difficulties and introduced uncertainties in the separator’s fluids level readings, and thus eventually in the fluids saturation evaluation. Resistivity data obtained in real time were used to correct for the overestimated values of oil production during polymer injection attributed to the formation of the oil/water emulsion.


Article metrics loading...

Loading full text...

Full text loading...


  1. Alexis, D., Varadarajan, D., Kim, D. H., Winslow, G., and Malik, T.
    [2016] Evaluation of Innovative Associative Polymers for Low Concentration Polymer Flooding. Society of Petroleum Engineers. DOI: 10.2118/179696‑MS.
    https://doi.org/10.2118/179696-MS [Google Scholar]
  2. Aktas, F., Clemens, T., Castanier, L., and Kovscek, A. R.
    [2008] Viscous Oil Displacement via Aqueous Associative Polymers. SPE Symposium on Improved Oil Recovery, Tulsa, Oklahoma. DOI: 10.2118/113264‑MS.
    https://doi.org/10.2118/113264-MS [Google Scholar]
  3. Askarinezhad, R., Hatzignatiou, D. G., and Stavland, A.
    [2017a] Disproportionate Permeability Reduction of Water-Soluble Silicate Gelants - Importance of Formation Wettability. SPE Production & Operations. SPE-179589-MS. DOI: 10.2118/179589‑MS.
    https://doi.org/10.2118/179589-MS [Google Scholar]
  4. [2017b] Core-Based Evaluation of Associative Polymers as Enhanced Oil Recovery Agents in Oil-wet Formations, International Symposium of the Society of Core Analysts, Vienna, Austria, 27–30 August.
    [Google Scholar]
  5. Dupuis, G., Tabary, R., and Grassl, B.
    [2010] How to Get the Best Out of Hydrophobically Associative Polymers for IOR?New Experimental Insights. SPE. DOI: 10.2118/129884‑MS.
    https://doi.org/10.2118/129884-MS [Google Scholar]
  6. Dupuis, G., Rousseau, D., Tabary, R., and Grassl, B.
    [2011]. Flow of Hydrophobically Modified Water-Soluble-Polymer Solutions in Porous Media: New Experimental Insights in the Diluted Regime. SPE Journal, Vol. 16 (01). DOI: 10.2118/129884‑PA.
    https://doi.org/10.2118/129884-PA [Google Scholar]
  7. Huh, C., and Pope, G. A.
    [2008] Residual Oil Saturation from Polymer Floods: Laboratory Measurements and Theoretical Interpretation. SPE Symposium on Improved Oil Recovery, Tulsa, Oklahoma, USA. DOI: 10.2118/113417‑MS.
    https://doi.org/10.2118/113417-MS [Google Scholar]
  8. Koh, H., Lee, V. B., and Pope, G. A.
    [2016] Experimental Investigation of the Effect of Polymers on Residual Oil Saturation. SPE Improved Oil Recovery Conference, Tulsa, Oklahoma, USA. DOI: 10.2118/179683‑MS.
    https://doi.org/10.2118/179683-MS [Google Scholar]
  9. Lake, L.W.
    [1989]. Enhanced Oil Recovery, 314–353. Englewood Cliffs, New Jersey: Prentice Hall.
    [Google Scholar]
  10. Mennella, A., Chiappa, L., Lockhart, T. P., and Burrafato, G.
    [2001] Candidate and Chemical Selection Guidelines for Relative Permeability Modification (RPM) Treatments. SPE Production & Facilities. Vol. 16 (03). DOI: 10.2118/72056‑PA.
    https://doi.org/10.2118/72056-PA [Google Scholar]
  11. Pye, D. J.
    [1964] Improved Secondary Recovery by Control of Water Mobility. Journal of Petroleum Technology. Vol. 16 (08). DOI: 10.2118/845‑PA.
    https://doi.org/10.2118/845-PA [Google Scholar]
  12. Qi, P., Ehrenfried, D. H., Koh, H., and Balhoff, M. T.
    [2016] Reduction of Residual Oil Saturation in Sandstone Cores by Use of Viscoelastic Polymers. SPE Journal. DOI: 10.2118/179689‑PA.
    https://doi.org/10.2118/179689-PA [Google Scholar]
  13. Ranjbar, M., Rupp, J., Pusch, G., and Meyn, R.
    [1992] Quantification and Optimization of Viscoelastic Effects of Polymer Solutions for Enhanced Oil Recovery. SPE/DOE Enhanced Oil Recovery Symposium, Tulsa, Oklahoma. DOI: 10.2118/24154‑MS.
    https://doi.org/10.2118/24154-MS [Google Scholar]
  14. Reichenbach-Klinke, R., Langlotz, B., Wenzke, B., Spindler, C., and Brodt, G.
    [2011]. Associative Copolymer with Favorable Properties for the Application in Polymer Flooding. SPE International Symposium on Oilfield Chemistry, 11–13 April, Woodlands, Texas, USA. DOI: 10.2118/141107‑MS.
    https://doi.org/10.2118/141107-MS [Google Scholar]
  15. Reichenbach-Klinke, R., Stavland, A., Langlotz, B., Wenzke, B., and Brodt, G.
    [2013] New Insights into the Mechanism of Mobility Reduction by Associative Type Copolymers. SPE Enhanced Oil Recovery Conference, Kuala Lumpur, Malaysia. DOI: 10.2118/165225‑MS.
    https://doi.org/10.2118/165225-MS [Google Scholar]
  16. Reichenbach-Klinke, R., Stavland, A., Strand, D., Langlotz, B., and Brodt, G.
    [2016] Can Associative Polymers Reduce the Residual Oil Saturation?SPE EOR Conference at Oil and Gas West Asia, Muscat, Oman. DOI: 10.2118/179801‑MS.
    https://doi.org/10.2118/179801-MS [Google Scholar]
  17. Sandiford, B. B.
    [1964] Laboratory and Field Studies of Water Floods Using Polymer Solutions to Increase Oil Recoveries. Journal of Petroleum Technology. Vol. 16 (08). DOI: 10.2118/844‑PA.
    https://doi.org/10.2118/844-PA [Google Scholar]
  18. Seright, R. S., Fan, T., Wavrik, K., Wan, H., Gaillard, N., and Favéro, C.
    [2011] Rheology of a New Sulfonic Associative Polymer in Porous Media. SPE Reservoir Evaluation & Engineering. Vol. 14 (06). DOI: 10.2118/141355‑PA.
    https://doi.org/10.2118/141355-PA [Google Scholar]
  19. Sheng, J. J., Leonhardt, B., and Azri, N.
    [2015] Status of Polymer-Flooding Technology. Journal of Canadian Petroleum Technology. Vol. 54 (02). DOI: 10.2118/174541‑PA.
    https://doi.org/10.2118/174541-PA [Google Scholar]
  20. Sorbie, K.S.
    [1991] Polymer-Improved Oil Recovery. Glasgow and London: Blackie.
    [Google Scholar]
  21. Stavland, A., Andersen, K. I., Sandoey, B., Tjomsland, T., and Mebratu, A. A.
    [2006] How To Apply a Blocking Gel System for Bullhead Selective Water Shutoff: From Laboratory to Field. SPE/DOE Symposium on Improved Oil Recovery, Tulsa, Oklahoma, USA. DOI: 10.2118/99729‑MS.
    https://doi.org/10.2118/99729-MS [Google Scholar]
  22. Tripathi, A., Tam, K.C., and GarethH. McKinley, G.H.
    [2006] Rheology and Dynamics of Associative Polymers in Shear and Extension: Theory and Experiments. Macromolecules Vol. 39, 1981–1999.
    [Google Scholar]
  23. Urbissinova, T. S., Trivedi, J., and Kuru, E.
    [2010] Effect of Elasticity during Viscoelastic Polymer Flooding a Possible Mechanism of Increasing the Sweep Efficiency. Journal of Canadian Petroleum Technology. Vol. 49 (12). DOI: 10.2118/133471‑PA.
    https://doi.org/10.2118/133471-PA [Google Scholar]
  24. Wang, D., Cheng, J., Yang, Q., Wenchao, G., Qun, L., and Chen, F.
    [2000] Viscous-Elastic Polymer Can Increase Microscale Displacement Efficiency in Cores. SPE Annual Technical Conference and Exhibition, Dallas, Texas. DOI: 10.2118/63227‑MS.
    https://doi.org/10.2118/63227-MS [Google Scholar]
  25. Wang, D., Cheng, J., Xia, H., Li, Q., and Shi, J.
    [2001a] Viscous-Elastic Fluids Can Mobilize Oil Remaining after Water-Flood by Force Parallel to the Oil-Water Interface. SPE Asia Pacific Improved Oil Recovery Conference, Kuala Lumpur, Malaysia. DOI: 10.2118/72123‑MS.
    https://doi.org/10.2118/72123-MS [Google Scholar]
  26. Wang, D., Xia, H., Liu, Z., and Yang, Q.
    [2001b] Study of the Mechanism of Polymer Solution with Visco-Elastic Behavior Increasing Microscopic Oil Displacement Efficiency and the Forming of Steady “Oil Thread” Flow Channels. SPE Asia Pacific Oil and Gas Conference and Exhibition, Jakarta, Indonesia. DOI: 10.2118/68723‑MS.
    https://doi.org/10.2118/68723-MS [Google Scholar]
  27. Zaitoun, A. and Kohler, N.
    [1988] Two-Phase Flow through Porous Media: Effect of an Adsorbed Polymer Layer. SPE Annual Technical Conference and Exhibition, Houston, Texas. DOI: 10.2118/18085‑MS.
    https://doi.org/10.2118/18085-MS [Google Scholar]
  28. Evani
    [1983] Enhanced Oil Recovery Process Using a Hydrophobic Associative Composition Containing a Hydrophilic/Hydrophobic Polymer, U.S. Pat. No. 4,432,881.
    [Google Scholar]

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error