Mechanical and thermal stability of polyacrylamide-based microgel products for EOR

G. Dupuis, R. S. Al-Maamari, A. R. Al-Hashmi, H. H. Al-Sharji, A. Zaitoun

Research output: Chapter in Book/Report/Conference proceedingConference contribution

13 Citations (Scopus)


In a previous work (Zaitoun, et al., 2012), a study of the shear stability of different EOR polymers was reported. Shear stability was found to directly correlate to chain flexibility. Thus, for a flexible coil such as polyacrylamide, the presence of large monomer groups (e.g. ATBS, NVP) leads to an increase of its rigidity, hence enhancing its shear stability. However, these polymers remain highly shear sensitive in comparison to the rodlike Xanthan gum. In this paper shear and thermal stability studies of different microgels are reported. Microgels are micrometric hydrophilic gel particles composed of partially cross-linked polyacrylamide-based chains. These microgels are already used for water shut-off treatments and conformance control. Because of their stability, they could be used in the future as sweep improvers EOR chemicals. Comparative tests were performed with microgels and three different polyacrylamide-based EOR polymers in terms of shear and thermal stability. The impact of the internal cross-linking density, the size and the conditioning on microgels mechanical stability was investigated. For each microgel, solutions were prepared at different salinities and aged in ovens at 80, 105 and 140°C over one month in oxygen-free conditions to check their thermal stability. Results showed that microgels maintain their integrity over a wide range of shear rate (up to 1.2×106 s-1) behaving like the rodlike Xanthan gum, whereas classical polyacrylamide-based polymers loose more than 50% of their initial viscosity at shear rate as low as 104 to 105 s-1. No difference in behavior is observed for the product prepared in powder or in emulsion form. Finally, at the highest temperature investigated (i.e. 140°C), thermal degradation is minimal for the microgels with low cross-linking densities and no thermal degradation has been observed for the microgels with the highest cross-linking densities. The exceptional mechanical and thermal stability of the polyacrylamide-based microgels and their easiness to be tailored for the required application make these chemicals excellent candidates as future sweep improvers under harsh reservoir conditions in which other conventional polymers might fail.

Original languageEnglish
Title of host publicationSociety of Petroleum Engineers - International Symposium on Oilfield Chemistry 2013
PublisherSociety of Petroleum Engineers (SPE)
Number of pages11
ISBN (Print)9781627481779
Publication statusPublished - 2013
EventInternational Symposium on Oilfield Chemistry 2013 - The Woodlands, TX, United States
Duration: Apr 8 2013Apr 10 2013

Publication series

NameProceedings - SPE International Symposium on Oilfield Chemistry
ISSN (Print)1046-1779


OtherInternational Symposium on Oilfield Chemistry 2013
Country/TerritoryUnited States
CityThe Woodlands, TX

ASJC Scopus subject areas

  • General Chemistry
  • General Chemical Engineering
  • Energy Engineering and Power Technology


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