Self-healing hydrogels and their action mechanism in oil–gas drilling and development engineering: A systematic review and prospect

Research progress of self-healing hydrogels based on both reversible covalent and reversible non-covalent bonds are systematically reviewed. The preparation methods, mechanical properties, healing mechanisms, and effects of self-healing hydrogels with different healing methods are compared and analyzed. Based on the unique characteristics of different types of self-healing hydrogels and current problems of conventional polymer gels used in the fields of drilling fluids and enhanced oil & gas recovery, the self-healing hydrogel-based materials used as blocking agent, lost circulation control agent, and wellbore strengthening agent that can significantly improve the performance of drilling fluids, as well as profile control agent, water shutoff agent, and profile control-displacement agent that can significantly enhance oil & gas recovery are proposed. This article will provide theoretical and technical references for the future application of self-healing hydrogels in the field of oil–gas drilling and development engineering. •Self-healing hydrogels based on covalent and non-covalent bonds are reviewed.•Hydrogels with different healing mechanisms show different performances.•Action mechanisms of self-healing gels used in drilling fluid are described.•Action mechanisms of self-healing gels used in enhanced oil recovery are shown.