The ability to precisely complete ultra-long laterals and a desire to create highly-complex fracture networks has encouraged adoption of friction reducers.
Most operators use a two-fluid system to achieve maximum proppant transport, while reducing pipe friction – guar and slickwater. This system has traditionally introduced increased treatment cost and operational complexity.
Crosslinked guar increases the viscosity of water, enabling proppant to be carried further into the formation. Due to the high viscosity of the guar mixture, pipe friction is increased which offsets the horsepower needed. In order to reduce pipe friction to an operable level, a friction reducer is added to the mixture. These thick crosslinked fluids leave behind residue and break imprecisely, reducing permeability.
Slickwater systems contain non-viscous uncrosslinked fluids that enable high pump rates to carry proppant deeper, creating complex fractures. In addition, larger volumes of water are often needed, requiring more horsepower to maintain the high pump rates and flowback recovery.