Wellbore treatment compositions comprising hydrophilically modified polymers and nonionic surfactants

The disclosed compositions and methods utilize hydrophilic polymers modified by the incorporation of one or more hydrophilic side groups. The polymers may exhibit physical association in solution at a specific temperature so as to provide a significant increase in viscosity at the specific temperature. The viscosity of such systems is substantially increased by the further inclusion of one or more hydrophilic components that may exhibit physical association in solution at one or more temperature trigger points and also associate with the one or more hydrophilic polymers modified by the incorporation of one or more hydrophilic side groups.