Dilute iota- and kappa-Carrageenan solutions with high viscosities in high salinity brines
Stefan Iglauer, Yongfu Wu, Patrick J. Shuler, Yongchun Tang, William A. Goddard III
Abstract
We evaluated the rheological characteristics of ι- and κ-Carrageenan in aqueous solutions. Viscosities strongly increased with increasing polymer concentration or salinity. Monovalent Na^+ cations were more effective in increasing viscosity than divalent Ca^(2+) cations. A more complex brine containing Na^+, Mg^(2+) and Ca^(2+) cations also showed high viscosities at a high salinity. We observed shear thinning behavior for these polysaccharide solutions. We explain these rheological phenomena with molecular processes, specifically the conformation change of the ι-Carrageenan from random coil to double helix. In the context of enhanced oil recovery, ι-Carrageenan solutions can reach much higher viscosities at high salinities than standard polyacrylamide solutions. Moreover, Carrageenans are renewable, nontoxic, green substances.
Group Members
Iglauer, S., Wu, Y., Shuler, P. J., Tang, Y., & III, W. A. G. (2010). Dilute iota- and kappa-Carrageenan solutions with high viscosities in high salinity brines. *Journal of Petroleum Science and Engineering*, *75*(3-4), 304-311. https://doi.org/10.1016/j.petrol.2010.11.025