Abstract: In order to solve the problem of water plugging and water control in high water-cut reservoirs, a supramolecular gel plugging agent system was assembled by synergistic assembly of weakly crosslinked zwitterionic polymer and surfactant with physical and chemical reactions. The best conditions for assembling self-healing gel (SHG) self-repairing gel plugging agent were optimized, by testing the apparent viscosity of the gel system under different influencing factors. Rheological characteristics and shear recovery of the plugging agent gel were tested by rheometer. The stability of the system was tested by treating the gel with brine. The plugging and water control ability of the plugging agent were tested by coreflooding experiment. Scanning electron microscopy was used to analyze the gelling and water shut-off and water control mechanisms of the plugging agent gel. The results show that the viscosity of the plugging agent gel has excellent self-assembly recovery performance after shearing. In addition, the plugging agent gel has good plugging capability, thermal stability and salt resistance. The plugging effect of the plugging agent on high permeability core is better than that on low permeability core. During coreflooding experiment, it is difficult for the displacing fluid to completely sweep through every flow channel of the core. When the water flows through the core, the oil flow will have trouble in replacing the water flow channel. In other words, it is difficult to reduce the production water cut. The plugging agent forms a tree-like network structure with self-repairing function through multiple actions, aiming at the realization of the hydrophobic and water control functions of the system.

Key words: High water cut, Self-healing, Gel, Water plugging, Water control