A New Approach to Polymer Flooding: Effects of Early Polymer Injection and Wettability on Final Oil Recovery
- Jose L. Juárez-Morejón (University of Bordeaux) | Henri Bertin (University of Bordeaux) | Aziz Omari (University of Bordeaux) | Gerald Hamon (Total) | Christophe Cottin (Total) | Danielle Morel (Total) | Carolina Romero (Total) | Gilles Bourdarot (Total)
- Document ID
- Society of Petroleum Engineers
- SPE Journal
- Publication Date
- February 2019
- Document Type
- Journal Paper
- 129 - 139
- 2019.Society of Petroleum Engineers
- Polymer flooding, wettability, dispersion, maturity, secondary, tertiary
- 28 in the last 30 days
- 92 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 10.00|
|SPE Non-Member Price:||USD 30.00|
An experimental study of polymer flooding is presented here, focusing on the influence of initial core wettability and flood maturity (volume of water injected before polymer injection) on final oil recovery. Experiments were performed using homogeneous Bentheimer Sandstone samples of similar properties. The cores were oilflooded using mineral oil for water-wet conditions and crude oil (after an aging period) for intermediate-wet conditions; the viscosity ratio between oil and polymer was kept constant in all experiments. Polymer, which is a partially hydrolyzed polyacrylamide (HPAM), was used at a concentration of 2,500 ppm in a moderate-salinity brine. The polymer solution was injected in the core at different waterflood-maturity times [breakthrough (BT) and 0, 1, 1.75, 2.5, 4, and 6.5 pore volumes (PV)].
Coreflood results show that the maturity of polymer injection plays an important role in final oil recovery, regardless of wettability. The waterflood-maturity time 0 PV (polymer injection without initial waterflooding) leads to the best sweep efficiency, whereas final oil production decreases when the polymer-flood maturity is high (late polymer injection after waterflooding). A difference of 15% in recovery is observed between early polymer flooding (0 PV) and late maturity (6.5 PV). Concerning the effect of wettability, the recovery factor obtained with water-wet cores is always lower (from 10 to 20%, depending on maturity) than the values obtained with intermediate-wet cores, raising the importance of correctly restoring core wettability to obtain representative values of polymer incremental recovery. The influence of wettability can be explained by the oil-phase distribution at the pore scale. Considering that the waterflooding period leads to different values of the oil saturation at which polymer flooding starts, we measured the core dispersivity using a tracer method at different states. The two-phase dispersivity decreases when water saturation increases, which is favorable for polymer sweep.
This study shows that in addition to wettability, the maturity of polymer flooding plays a dominant role in oil-displacement efficiency. Final recovery is correlated to the dispersion value at which polymer flooding starts. The highest oil recovery is obtained when the polymer is injected early.
|File Size||1 MB||Number of Pages||11|
Anderson, W. G. 1986. Wettability Literature Survey—Part 1: Rock/Oil/Brine Interactions and the Effects of Core Handling on Wettability. J Pet Technol 38 (10): 1125–1144. SPE-13932-PA. https://doi.org/10.2118/13932-PA.
Asghari, K. and Nakutnyy, P. 2008. Experimental Results of Polymer Flooding of Heavy Oil Reservoir. Presented at the Canadian International Petroleum Conference, Calgary, 17–19 June. PETSOC-2008-189. https://doi.org/10.2118/2008-189.
Buckley, J. S., Liu, Y., and Monsterleet, S. 1998. Mechanisms of Wetting Alteration by Crude Oils. SPE J. 3 (1): 54–61. SPE-37230-PA. https://doi.org/10.2118/37230-PA.
Cottin, C., Bourgeois, M., Bursaux, R. et al. 2014. Secondary and Tertiary Polymer Flooding on Highly Permeable Reservoir Cores: Experimental Results. Presented at the SPE EOR Conference at Oil and Gas West Asia, Muscat, Oman, 31 March–2 April. SPE-169692-MS. https://doi.org/10.2118/169692-MS.
Jadhunandan, P. P. and Morrow, N. R. 1995. Effect of Wettability on Waterflood Recovery for Crude-Oil/Brine/Rock Systems. SPE Res Eng 10 (1): 40–46. SPE-22597-PA. https://doi.org/10.2118/22597-PA.
Juárez-Morejón, J. L., Bertin, H., Omari, A. et al. 2017. Spontaneous Imbibition as Indicator of Wettability Change During Polymer Flooding. Oral presentation given at the IOR 2017–19th European Symposium on Improved Oil Recovery, Stavanger, Norway, 24–27 April. https://doi.org/10.3997/2214-4609.201700334.
Koh, H., Lee, V. B., and Pope, G. A. 2016. Experimental Investigation of the Effect of Polymers on Residual Oil Saturation. Presented at the SPE Improved Oil Recovery Conference, Tulsa, 11–13 April. SPE-179683-MS. https://doi.org/10.2118/179683-MS.
Lake, W. L. 1989. Enhanced Oil Recovery. Upper Saddle River, New Jersey: Prentice Hall.
Levitt, D., Jouenne, S., Bondino, I. et al. 2013. Polymer Flooding of Heavy Oil Under Adverse Mobility Conditions. Presented at the SPE Enhanced Oil Recovery Conference, Kuala Lumpur, 2–4 July. SPE-165267-MS. https://doi.org/10.2118/165267-MS.
Peksa, A. E., Wolf, K.-H. A. A., and Zitha, P. L. J. 2015. Bentheimer Sandstone Revisited for Experimental Purposes. Mar. Petrol. Geol. 67 (November): 701–719. https://doi.org/10.1016/j.marpetgeo.2015.06.001.
Qi, P., Ehrenfried, D. H., Koh, H. et al. 2016. Reduction of Residual Oil Saturation in Sandstone Cores Using Viscoelastic Polymers. Presented at the SPE Improved Oil Recovery Conference, Tulsa, 11–13 April. SPE-179689-MS. https://doi.org/10.2118/179689-MS.
Runkel, R. L. 1996. Solution to the Advection-Dispersion Equation: Continuous Load of Finite Duration. J. Environ. Eng. 122 (9): 830–832. https://doi.org/10.1061/(ASCE)0733-9372(1996)122:9(830).
Shashvat, D. and Mohanty, K. K. 2015. Fingering Function for Unstable Immiscible Flows. Presented at the SPE Reservoir Simulation Symposium, Houston, 23–25 February. SPE-173290-MS. https://doi.org/10.2118/173290-MS.
Shiran, B. S. and Skauge, A. 2015. Wettability and Oil Recovery by Polymer and Polymer Particles. Presented at the SPE Asia Pacific Enhanced Oil Recovery Conference, Kuala Lumpur, 11–13 August. SPE-174568-MS. https://doi.org/10.2118/174568-MS.
Skauge, T., Vik, B. F., Ormehaug, P. A. et al. 2014. Polymer Flood at Adverse Mobility Ratio in 2D Flow by X-Ray Visualization. Presented at the SPE EOR Conference at Oil and Gas West Asia, Muscat, Oman, 31 March–2 April. SPE-169740-MS. https://doi.org/10.2118/169740-MS.
Thomas, G. H., Countryman, G. R., and Fatt, I. 1963. Miscible Displacement in a Multiphase System. SPE J. 3 (3): 189–196. SPE-538-PA. https://doi.org/10.2118/538-PA.
Vermolen, E. C. M., van Haasterecht, M. J. T., and Masalmeh, S. K. 2014. A Systematic Study of the Polymer Visco-Elastic Effect on Residual Oil Saturation by Core Flooding. Presented at the SPE EOR Conference at Oil and Gas West Asia, Muscat, Oman, 31 March–2 April. SPE-169681-MS. https://doi.org/10.2118/169681-MS.
Wang, D., Cheng, J., Yang, Q. et al. 2000. Viscous-Elastic Polymer Can Increase Microscale Displacement Efficiency in Cores. Presented at the SPE Annual Technical Conference and Exhibition, Dallas, 1–4 October. SPE-63227-MS. https://doi.org/10.2118/63227-MS.
Wassmuth, F. R., Green, K., Hodgins, L. et al. 2007. Polymer Flood Technology for Heavy Oil Recovery. Presented at the Canadian International Petroleum Conference, Calgary, 12–14 June. PETSOC-2007-182. https://doi.org/10.2118/2007-182.