.... However, due to the tight shale formation, efficient proppant pack cleanup is critical to minimize polymer residue. The breaker systems include coated and uncoated oxidative breakers with an enzyme breaker added during the tail-in stages to break down the viscosity and aid in fracture fluid cleanup...

... criterion stress anisotropy shale formation hydraulic fracture propagation Introduction Multi-stage hydraulic fracturing through a horizontal well plays an essential role to the economic development of shale gas reservoirs owing to their extremely low permeability ( Frantz and Jochen, 2005...