Using β-mannanase as the gel breaker in petroleum extraction: recent advances and future perspectives

Guar gum and its derivatives have been widely used as thickeners in hydraulic fracturing operations for petroleum extraction. These polymers tend to accumulate in the formation fractures during hydraulic fracturing, forming filter cakes that hinder the oil recovery. Although oxidants or acids are often added to fracturing fluids to degrade filter cakes, their use of oxidants or acids generates unnecessary byproducts (such as SO₄^2-) and may lead to damage and infrastructure corrosion. β-mannanase can randomly hydrolyze the β-1,4-glycosidic bonds in the guar gum main chain, reducing its molecular weight and viscosity, making it an environmentally friendly and efficient gel breaker. This article introduces the degradation mechanism of guar gum by β-mannanase, focusing on the application of β-mannanase as a gel breaker in hydraulic fracturing for petroleum extraction, and explores the widespread application of β-mannanase in fracturing operations in the future.