Tailor-modified starch/cyclodextrin-based polymers for use in tertiary oil recovery

Polymer injection into an oil field to provide water permeability reduction has been shown to be an effective control of water production from oil wells. This method relies on adsorption of the polymer on rock walls within the pores of the reservoir and it is therefore important to consider this ability when selecting the polymer to inject. In this paper the role of charge density and molecular weight on modified cationic polysaccharides has been studied to determine the proper combinations of each to provide the enhanced adsorption. The adsorption tests were preformed using colloidal titration on a range of core or rock samples taken from oil wells in Saskatchewan in an attempt to reveal the structure–property relation. Three commercial cationic starches along with two self-modified starches were studied. Apart from cationic starches a novel branched polymer based on cyclodextrin was also evaluated for its adsorption on the rock sample with well-defined structure.