Rheological and fracturing characteristics of a cationic guar gum

Guar gum (GG) fracturing fluid is frequently used in the field of enhanced oil recovery. GG fracturing fluids must have increased the temperature resistance and salt tolerance due to the complexity of drilled formations. In this study, the cationic guar gum (GG-GTA) samples for fracturing fluids were successfully synthesized, which can even resist 120 °C. It can be directly prepared by formation water, even sea water. Besides hydrogen bonds and covalent bonds, the additional cationic groups can strengthen the network even more in the GG-GTA fracturing fluids, which is why the GG-GTA fracturing fluids had stronger rheological properties than the GG fracturing fluids. The GG-GTA fracturing fluids performed well in terms of temperature resistance, salt tolerance, pressure resistance, and proppant carrying capacity. In addition, the GG-GTA gel-breaking caused little damage to core permeability because it exhibited low viscosity, interfacial tension, and surface tension. These results provide a solid foundation for the application of GG-GTA fracturing fluids in oilfield production.