Evidences of CDG formation and possible interpretations of core flood studies

  • Daniela Alzate López Universidad Nacional de Colombia. Facultad de Minas.
  • Juan Manuel León Ecopetrol S.A.
  • Fernando Cabrera Nalco Champion
  • Eduardo Manrique MI3 Petroleum Engineering


Colloidal Dispersion Gels (CDG’s) have been successfully tested in several countries including Colombia. However, despite numerous successful field results reported in the literature, laboratory-scale experiments have generated controversy regarding the ability to inject CDG’s in large volumes without reducing injectivity while also improving sweep efficiency.

This paper summarizes the updates in microgel technologies, especially the Linked-Polymer Solutions (LPS) that have been also referred as CDG’s leading to misinterpretation of both systems. This brief review will also present the main mechanisms proposed for the formation of LPS in fluid:fluid studies and during its flow in porous media. This study also presents for the first time evidences of the possible mechanisms for the formation of CDG’s using a high molecular weight (MW) partially hydrolyzed polyacrylamide (HPAM) and Aluminum Citrate (Al(Cit)3) as a crosslinker using Dina Cretáceos Field, Colombia, synthetic brine at room temperature (25°C). The results generated during this study were used to re-interpret corefloods injecting CDG in Berea and Tello Field, Colombia, core plugs at different experimental conditions.

The main difference identified between LPS and CDG systems is the viscosity behavior in the presence of Al(Cit)3. LPS reports a decrease in viscosities while CDGs shows an increase in viscosities in the presence of crosslinker. This difference is due to the use of different high MW HPAM polymers. However, the crosslinking of the trivalent ion (Al3+) and the negatively charged carboxylic groups of the polymer of both microgels occurs through intra-and inter-molecular interactions leading to different particle size or hydrodynamic diameter distributions (HDD). The rate and type of HDD is dependent of polymer and crosslinker concentration. These results were also compared with a CDG systems using Chromium Acetate (Cr(Ac)3) as a crosslinker used in Loma Alta Sur Field, Argentina. The crosslinkers used (Al3+ y Cr3+) forming CDG suggests similar crosslinking mechanisms but shows differences in HDD. However, the difference in the experimental conditions of studies documented makes difficult developing a more detailed comparison. Finally, the re-interpretation of CDG corefloods suggests that the main operating mechanisms include viscosity effects, adsorption, straining and log-jamming as proposed for LPS systems. However, viscosity effects and the gradual blocking of pore channels (log-jamming) seem to be more dominant in CDG than LPS systems. The results of this study will contribute with the understanding of the CDG’s and also provides guidance to improve the evaluation and research of the technology at lab scale.

Palabras clave: CDG (Colloidal dispersion Gels), Polyacrylamide, Hydrodynamic Diameter Distributions, Microgels, Enhanced Oil Recovery (EOR)


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1. Aarra, M., Bjorvisk, M., Hoiland, H., Skodvin, T., Standnes, D. C., & Skauge, A. (2005). Linked Polymer Solutions for Improved Oil Recovery By Waterflooding. 13th European Symposium on Improved Oi Recovery.

2. Abdulbaki, M., Huh, C., Sepehrnoori, K., Delshad, M., & Varavei, A. (2014). A critical review on use of polymer microgels for conformance control purposes. Journal of Petroleum Science and Engineering. Elsevier. doi:10.1016/j.petrol.2014.06.034.

3. Alzate, D. (2016). Interpretación de los mecanismos fenomenológicos del proceso de inyección de Geles de Dispersión Coloidal (CDG) en un yacimeinto de hidrocarburos. Universidad Nacional de Colombia. Retrieved from http://www.bdigital.unal.edu.co/52357/

4. Bjørsvik, M., Høiland, H., & Skauge, A. (2008). Formation of colloidal dispersion gels from aqueous polyacrylamide solutions. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 317, 504–511. doi:10.1016/j.colsurfa.2007.11.025

5. Bolandtaba, S. F., & Skauge, A. (2011). Network Modeling of EOR Processes: A Combined Invasion Percolation and Dynamic Model for Mobilization of Trapped Oil. Transport in Porous Media. doi:10.1007/s11242-011-9775-0

6. Castro, R. H. (2011). Análisis de un Proceso de Inyección de Geles de Dispersión Coloidal (CDG) usando simulación numérica. Tesis de Maestría En Ingeniería de Hidrocarburos, Universidad Industrial de Santander, Escuela de Ingeniería de Petróleos. doi:10.1007/s13398-014-0173-7.2

7. Castro, R., Maya, G., Sandoval, J., León, J., Zapata, J., Lobo, A., … Manrique, E. (2013). Colloidal Dispersion Gels (CDG) in Dina Cretáceos Field : From Pilot Design to Field Implementation and Performance (SPE 165273). SPE Improved Oil Recovery Symposium Held in Kuala Lumpur, Malaysia.

8. Díaz, D., Saez, N., Cabrera, M., Manrique, E., Romero, J., Kazempour, M., & Aye, N. (2015).CDG in a Heterogeneous Fluvial Reservoir in Argentina : Pilot and Field Expansion Evaluation. SPE Enhanced Oil Recovery Conference -EORC. Kuala Lumpur, Malaysia.

9. Gall, J. W. (1973). Subterranean Formation Permeability Correction. US Patent No 3,762,476.

10. Instruments, M. (2011). Inform White Paper: Dynamic Light Scattering, Common terms defined. Malvern Guides, 1–6.

11. Kaszuba, M., McKnight, D., Connah, M. T., McNeil- Watson, F. K., & Nobbmann, U. (2008). Measuring sub nanometre sizes using dynamic
light scattering. Journal of Nanoparticle Research, 10(5), 823–829. doi:10.1007/s11051-007-9317-4

12. León, J. M., Zapata, J. F., Castro, R. H., Reyes, J. D., Ecopetrol, S. A., Fernando, A., ... (2015). Inyección de Geles de Dispersión Coloidal para el Mejoramiento de la Eficiencia de Barrido Volumétrica en Procesos de Inyección de Agua : Del Piloto a la Expansión. XVI Congreso Colombiano Del Petróleo y Gas, (97), 1–15.

13. Manrique, E., Reyes, S., Romero, J., Aye, N., Kiani, M., Thomas, C., … Cabrera, F. (2014). Colloidal Dispersion Gels (CDG): Field Projects Review (SPE 169705). SPE/DOE EOR Conference at Oil and Gas West Asia. Muscat, Oman.

14. Moffit, P. D., Zornes, D. R., Moradi-Araghi, A., & McGovern, J. M. (1990). Application of Freshwater and Brine Polymerflooding in the North Burbank Unit (NBU), Osage County, Oklahoma. 65Th Annual SPE Tech Conf (New Orleans, 9/23-26/90) Proc [G - Eor/General Petroleum Engineering], (199046), 59–71. Retrieved from http://search.ebscohost.com/ login.aspx?direct=true&db=pta&AN=491865 &site=ehost-live

15. Nelson, E. (1967). Dynamical Theories of Brownian Motion. Mathematical Notes, 131(6), 2381–2396. doi:10.1103/PhysRev.131.2381

16. Romero, L. (2009). Colloidal Dispersion Gels (CDG) Versus Polymer Flooding for EOR. In Canadian International Petroleum Conference (p. 2009).

17. Selle, O. M., Fischer, H., Standnes, D. C., Auflem, I. H., Lambertsen, A. M., Svela, P. E., … Melien, I. (2013). Offshore Polymer / LPS Injectivity Test with Focus on Operational Feasibility and Near Wellbore Response in a Heidrun Injector (SPE 166343 ). SPE Annual Technical Conference and Exhibition Held in New Orleans, Louisiana.

18. Shook, G. M., Pope G. A., & Asakawa, K. (2009). Determining Reservoir Properties and Flood Performance From Tracer Test Analysis (SPE 124614). SPE Annual Technical Conference and Exhibition Held in New Orleans, Louisiana.

19. Skauge, T., Djurhuus, K., Hetland, S., Spildo, K., & Skauge, A. (2011). Offshore EOR Implementation – LPS Flooding. 16th European Symposium on Improved Oil Recovery,
(April 2011), 12–14. doi:10.3997/2214-4609.201404784

20. Skauge, T., Hetland, S., Spildo, K., Skauge, A., & Cipr, U. (2010). Nano-Sized Particles for EOR (SPE 129933). SPE Improved Oil Recovery Symposium Held in Tulsa, Oklahoma (April), 24–28. doi:10.2118/129933-ms

21. Sorbie, K. S. (1991). Polymer-improved oil recovery.

22. Spildo, K., Skauge, A., Aarra, M., & Tweheyo, M. (2009). A New Polymer Application for North Sea Reservoirs. SPE Reservoir Evaluation & Engineering, 12(3), 427–432. doi:https://doi.org/10.2118/113460-PA

23. Spildo, K., Skauge, A., & Skauge, T. (2010). Propagation of Colloidal Dispersion Gels (CDG) in Laboratory Corefloods (SPE 129927). SPE Improved Oil Recovery Symposium Held in Tulsa, Oklahoma.

24. Systems, P. (2012). Nanoplus. Zeta Potential and Nano Particle Analyzer. Retrieved from www.particulatesystems.com.