Impact of HVFR Loading Concentrations on its Viscoelastic Properties and Proppant Transport Performance

Abstract

Abstract In unconventional reservoirs, increasing the low formation conductivities through hydraulic fracturing may substantially increase oil production from wells. This work of improving the fracture conductivity could be conducted by distributing and transporting proppant within the fracture lengths using high fracture fluid concentrations. This research focused on three areas. First, it assessed the fluid rheology including the viscosity and elasticity of a high viscosity friction reducer (HVFR) and linear guar using deionized (DI) water at different fluid concentrations (i.e., 2, 4, and 8 gpt for the HVFR and 15, 25, and 35 ppt for linear guar), and measured the impact of the Marcellus total dissolved solids (TDS) on the HVFR using different fluid concentrations. Second, it employed a static model and three proppant mesh sizes (i.e., 40, 50, and 70) to analyze the proppant settling across the aforementioned HVFR and linear guar concentrations using DI water. It also measured the Marcellus TDS effect on the settling velocity of the proppant using different HVFR concentrations. Third, the study investigated proppant transport using a dynamic model, with measurements of the proppant transport conducted using different concentrations of the HVFR and linear guar, while also measuring the effect of Marcellus TDS on different concentrations of the HVFR. All the rheology measurements, static proppant settling velocity investigations, and dynamic proppant transport evaluations were conducted at room temperature (25°C). The results demonstrated that the HVFR provided higher viscosity and elasticity than linear guar. In addition, the HVFR provided superior static proppant suspension and excellent proppant transport performance in comparison to linear guar, but the HVFR’s viscosity and elasticity decreased substantially when it was prepared using TDS water, despite increasing the HVFR concentration from 2 to 8 gpt. Therefore, different concentrations of the HVFR and linear guar must be used to measure fracture fluid rheology, the static settling velocity of the proppant, and proppant transport inside the dynamic system. Also, measuring the effect of the Marcellus TDS on HVFRs at different fluid concentrations is crucial for improving the results of hydraulic fracture operations.