Mussel-inspired hydrogel particles with selective adhesion characteristics for applications in reservoir fracture control

Abstract

The complex fractures in low permeability and ultra-low permeability reservoirs may serve as dominant channels, resulting in the channeling of injection water and extremely low sweep efficiency. Polyacrylamide hydrogel particles as fracture control agents can effectively plug and adjust channeling pathways. However, the adhesion between the hydrogel particles and the rock wall is weak, restraining the long-term control effect. In this work, the developed mussel hydrogel particles with selective adhesion properties exhibited excellent reservoir adaptability (96 °C, 4.7 × 104 mg/L). The hydrogel particles can maintain a uniform dispersion during the injection process; they can adhere to the fracture wall in the reservoir environment. Furthermore, the adhesion mechanisms of mussel-inspired hydrogel particles on the fracture wall with different wettability and roughness are elucidated using atomic force microscopy. By showing stronger adhesion to the hydrophilic and neutral-wet surfaces than to the hydrophobic surfaces, mussel-inspired hydrogel particles can selectively control the water-wet channeling pathways. The fractured core model experiment and scanning electron microscopy results show that mussel-inspired adhesive hydrogel particles can withstand the water flushing and maintain stable adhesion to the fracture wall to guarantee long-term control effect, exhibit better flow control effect than ordinary hydrogel particles. This work can help better understand the characteristics of the interaction between the hydrogel particles and the fracture wall, providing guidance for the development of efficient fracture control agents.