Bio-enzyme gel breaker, and applications thereof

The invention relates to bio-enzyme gel breaker and applications thereof. The bio-enzyme gel breaker is an aqueous solution of beta-mannanase, alpha-galactosidase, and a cross-linking agent. According to an application method, by volume, 80 to 120 parts of a fracturing fluid base solution is mixed with 5 to 10 parts of the bio-enzyme gel breaker, and after gel forming, an obtained mixture is taken as a fracturing fluid. According to applications, galactosidase is used for removing a part of galactose residues on the side chains of galactomannan, so that mannose glycosidic bonds on the main chain of galactomannans are exposed, and then degradation effect of mannanase is adopted for selective degradation of galactomannan. Combination of the above two enzymes is capable of realizing high-efficiency rapid gel breaking of the fracturing fluid, reducing molecular weight of gel breaking products greatly, and reducing reservoir damage.