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Polymer Screening to Enhance Oil Recovery at High Salinity/High Temperature Conditions; Rheology and Static Adsorption Studies
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, IOR 2021, Apr 2021, Volume 2021, p.1 - 9
Abstract
This paper aims to investigate the polymer screening for a clayey sandstone reservoir with a temperature of 80ºC having a high salinity formation brine. Ordinary HPAM does not tolerate this condition, and thus we considered three modified HPAM based polymers in our study, i.e., Polymer-A, polymer-B and polymer-C. Polymer solutions are prepared in a brine that was considered representative for see water. The rheology of the solutions was measured by a Paar rheometer. Moreover, the static adsorption tests for polymer solutions prepared in the makeup water were performed using reservoir rock sample through the bleach method. According to the rheology results, the viscosity of the solutions was a function of the polymer molecular weight (i.e. B>A>C). In addition, the viscosity of 2000 ppm polymer solutions at different temperatures ranging from subsea to reservoir condition (4º to 80ºC) was measured. At a shear rate of 10 1/s, the viscosity reduction due to the increase in temperature from 4º to 80º C was 35% for polymer C, while it was 48% for polymer B. Polymer C has the lowest molecular weight, and exhibited the lowest adsorption on the reservoir rock, e.g. 51% lower than polymer B (the highest adsorption value).
Results shows that the studied polymers could be considered proper candidates for core flooding studies, among the studied polymers, polymer-C can be considered the most proper one. However, it is necessary to investigate its long-term stability.
The results of this paper provide useful insight for other polymer flooding studies at HS/HT conditions.