Impact of Fracturing Fluid Composition on Conductivity and Relative Permeability in Propped Fractures at Reservoir Conditions

This study investigates the impact of fracturing fluid composition on conductivity and two-phase flow behavior in proppant-packed fractures under reservoir conditions. Core-flooding experiments were conducted using Midland Basin rock and fluids to evaluate the effects of water source (fresh vs recycled), frac fluid design (slickwater vs high-viscosity friction reducer), and chemical additives on single- and two-phase flow properties across various production stages. Single-phase tests showed that freshwater-based formulations provided higher fracture conductivity than recycled water-based counterparts, likely due to lower salinity, reduced scaling, and more effective breakdown of the friction reducer polymer by the AP breaker. Two-phase unsteady-state tests demonstrated that oil injection restored fracture permeability following polymer retention, and aging-induced wettability alteration further reduced retained water saturation and enhanced oil mobility. Steady-state relative permeability measurements exhibited nonlinear, hysteretic behavior, suggesting that traditional X-curve models may overestimate flow performance in propped fractures. Overall, formulations prepared using freshwater and an anionic friction reducer delivered superior oil and brine relative permeabilities and a wider range of mobile oil saturation, highlighting their potential to improve fracture productivity.