1887

Abstract

Summary

1. Objective and Scope

Recently, polymer flooding has been a proven cEOR recovery process in viscous oil reservoirs. Polymer injection concept in reservoirs depleted by horizontal producers and supported by bottom aquifer has gained a considerable attention. In such concept, Polymer injectors are positioned above the aquifer and below the producers. Polymer injection design requires understanding how the time arrival of the oil bank is related to defined control parameters. A Model is introduced to explain how breakthrough time is related to these parameters and hence aid in designing a proper polymer injection.

2. Methodology, Procedure and Process

Based on the frontal advance theory in radial geometry, a parametric equation that relates the breakthrough time to the control parameters is introduced and its limitations is discussed. This mathematical model is validated using a reservoir simulator. The grid used is two dimensional where the reservoir is supported by an analytical aquifer. The model is also used to predict the breakthrough time of oil bank in two polymer trials in Oman using real data.

3. Results, Observations and Conclusions

The model is derived for an isotropic system and so it should be used whenever the permeability anisotropy is sufficiently close to unity. This result is consistent with the simulation result where the oil bank propagates in ellipses instead of circles when permeability anisotropy <<1. Also, the impact of gravity depends on the gravity number, and it is minimal under practical polymer injection design.

The model reveals that the remaining oil saturation, uncontrolled parameter, has a big impact on the oil bank breakthrough time, low remaining oil saturation results in a substantial delay in the breakthrough time besides low oil recovery, a result verified by simulation. For polymer viscosity, the first few centipoises are heavily impacting the arrival time until approximately 20–40cp beyond which the impact starts to be marginal. The model explains the early oil gain arrival in Nimr E6 Trial and the substantial delay in Nimr E157 Trial. The cause of the oil gain delay in Nimr E157 is mainly due to the low remaining oil saturation.

4. Novelty and Additive Information

The economic viability of polymer projects is mainly a function of the timing of the oil gain. The model enables engineers to design the optimal control parameters for reservoir with a given remaining oil saturation such that the water cut reversal is observed as early as possible.

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/content/papers/10.3997/2214-4609.202531013
2025-04-02
2026-02-19
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References

  1. Al Azri, N, Jamal, E., Murshidi, A., Al Mahrouqi, A., Al Busaidi, I., Kazzaz, A., Al Ajmi, W., Ramalingam, S., De Kruijf, A., Al Kharusi, B. and Brooks, D. [2010] Polymer Injection in Heavy Oil Reservoir under Strong Bottom Water Drive. In: All Days, 10OGWA. SPE.
    [Google Scholar]
  2. Al Ghafri, A.Y., Karpan, V., Al Sulaimani, H., Al Ramli, N. and van Batenburg, D. [2024] Insights Into Oil Bank Propagation in Reservoirs Under Bottom Aquifer Drive During Polymer Flooding. In: SPE Improved Oil Recovery Conference, 24IOR. SPE.
    [Google Scholar]
  3. Barenblatt, G.I., Entov, V.M. and Ryzhik, V.M. [1990] Classical Nonlinear Models of Homogeneous Fluid Flow Through Porous Media. Springer Netherlands.
    [Google Scholar]
  4. Bedrikovetsky, P. [1993] Mathematical Theory of Oil and Gas Recovery. Springer Netherlands.
    [Google Scholar]
  5. Brailovsky, I., Babchin, A., Frankel, M. and Sivashinsky, G. [2006] Fingering Instability in Water-Oil Displacement. Transport in Porous Media, 63(3), 363–380.
    [Google Scholar]
  6. Brooks, A.D., de Zwart, A.H., Bychkov, A., Al-Azri, N., Hern, C.Y., Al-Ajmi, W and Mukmin, M. [2010] Evaluation of EOR Techniques for Medium-Heavy Oil Reservoirs with a Strong Bottom Aquifer In South Oman. In: All Days, 10OGWA. SPE.
    [Google Scholar]
  7. Buckley, S. and Leverett, M. [1942] Mechanism of Fluid Displacement in Sands. Transactions of the AIME, 146(01), 107–116.
    [Google Scholar]
  8. Johnson, G., Neal, A., Lugo, N., Farthing, D. and Fordham, A. [2023] Creating New Economic Reserves Using Enhanced Oil Recovery Within a Mature Offshore Field. In: Day 3 Thu, September 07, 2023, 23OE. SPE.
    [Google Scholar]
  9. Mjeni, R., Gharbi, M., Lawati, S., Dickson, S.J., Ismaili, A.R., Hashmi, M., Amri, I., Belushi, K., Farajzadeh, R., Glasbergen, G., Karpan, V., Anand, A., Kruijf, S.D., Lomans, B. and Wever, D. [2022] Nimr Polymer Project: the Results of Multi-Well Trial in the Medium-Heavy Oil Reservoir with Strong Bottom Aquifer. In: Day 2 Tue, March 22, 2022. SPE.
    [Google Scholar]
  10. Pope, G.A. [1980] The Application of Fractional Flow Theory to Enhanced Oil Recovery. Society of Petroleum Engineers Journal, 20(03), 191–205.
    [Google Scholar]
  11. Welge, H.J. [1952] A Simplified Method for Computing Oil Recovery by Gas or Water Drive. Journal of Petroleum Technology, 4(04), 91–98.
    [Google Scholar]
  12. Yortsos, Y.C. and Hickernell, F.J. [1989] Linear Stability of Immiscible Displacement in Porous Media. SIAM Journal on Applied Mathematics, 49(3), 730–748.
    [Google Scholar]
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