Surface Gelatin-Coated β-Mannanase-Immobilized Lignin for Delayed Release of β-Mannanase to Remediate Guar-Based Fracturing Fluid Damage

[Image: see text] Herein, we developed an efficient and convenient method to address the problem of thickener decomposition in the low- permeability oilfield production process. It is crucial to design breakers that reduce viscosity by delaying thickener decomposition in appropriate environments. By using lignin in biomass as a substrate for β-mannanase immobilization (MIL), we fabricated a gel breaker, surface gelatin-coated β-mannanase-immobilized lignin (Ge@MIL). Through experiments and performance tests, we confirmed that the prepared Ge@MIL can release enzymes at a specific temperature, meanwhile having temperature-sensitive phase change properties and biodegradability. The results also show the tight tuning over the surface coating of Ge@MIL by a water-in-oil emulsion. Therefore, the prepared Ge@MIL has a promising application in the field of oil extraction as a green and efficient temperature-sensitive sustained-release capsule.