Phase behavior of colloidal nanoparticles and their enhancement effect on the rheological properties of polymer solutions and gels.

The interaction between nanoparticles and polymers has been of great interest in colloidal theory and novel materials. For example, the properties of polyacrylamide solutions and gels, which are usually used for conformance control and water shut-off in oilfields, can be improved with the addition of nanoparticles. This underlying mechanism and its applicability are investigated in this paper.

Selection of Optimum Surfactant Formulations with Ultralow Interfacial Tension for Improving the Oil Washing Efficiency.

Ultralow oil-water interfacial tension (IFT) has provided an important basis for screening optimum surfactant formulation for improving the oil washing efficiency. Thus, it is of great significance to further investigate the selection method for surfactant systems with ultralow IFT. In this study, a selection of surfactant systems with ultralow IFT was simplified by a method of comparing the equivalent alkane carbon number (EACN) of crude oil with the minimum alkane carbon number ( ) of surfactant mixtures.