Siliceous minerals, adsorption polyacrylamides

The influence of calcium on the adsorption of high molecular weight EOR polymers such as flexible polyacrylamides and semi-rigid xanthans on siliceous minerals and kaolinite has been studied in the presence of different sodium concentrations. Three mechanisms explain the increase in polyacrylamide adsorption upon addition of calcium (i) reduction in electrostatic repulsion by charge screening,... [Pg.227]

This study aims at determining the effects of calcium on the adsorption of polyacrylamides and xanthans on siliceous minerals and kaolinite. [Pg.228]

Adsorption on Siliceous Minerals. The adsorption of polyacrylamides on siliceous minerals in the presence of monovalent ions has been discussed previously (9, 10). While PAM adsorption is unaffected by monovalent ions since it is not governed by electrostatic factors, HPAM adsorption is increased due to reduction in electrostatic repulsion by charge screening. [Pg.229]

For polyacrylamides, as a function of polymer ionicity, the presence of calcium induces a maximum in intrinsic viscosity and a minimum in adsorption density on siliceous minerals. This holds important practical implications in EOR since an optimal polymer ionicity can be selected according to field conditions. [Pg.242]

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