Evaluation of Fracturing Fluid Impact on the Productivity of Multi-Stage Fractured Marcellus Shale Horizontal Wells

The objective of this study was to examine the effects of various fracturing fluids on proppant transport and its impact on the productivity of a Marcellus shale horizontal well with multiple hydraulic fracture stages. The available data from a Marcellus shale horizontal well were utilized to develop a reservoir model. The reliability of the model was confirmed by the close agreement between the predicted production by the model and the well production data. The impact of fracturing fluids on proppant transport during hydraulic fracturing and consequently on gas production from a Marcellus shale horizontal well were investigated by employing the reservoir models. Slickwater, compared to high viscosity friction reducers (HVFRs), was found to be less effective in horizontal Marcellus shale wells that are fractured in multiple stages. In treatment with the slickwater, all stimulation energy was directed towards the lower Marcellus shale and resulted in fractures with limited height leading to lower gas recovery. The application of the HVFRs resulted in higher fracture heights and improved production. 1. INTRODUCTION The increasing demand for energy from unconventional reservoirs worldwide, driven by the depletion of conventional resources, has spurred technological advancements in the economic recovery of oil and natural gas from unconventional shale reservoirs. The application of horizontal drilling and hydraulic fracturing techniques in recent years has successfully unlocked substantial reserves of natural gas, making shale gas development a critical component of the global oil and gas industry, especially in North America. The effective placement of proppant in a fracture has a significant impact on the conductivity of the hydraulic fracture and the productivity of the well. During hydraulic fracturing treatments, it is common to inject a slurry containing proppant to maintain the fracture conductivity after fracture closure. The slurry is composed of a carrier fluid, which can either be a low viscosity Newtonian fluid known as "slickwater," or a high viscosity shear-thinning fluid. A suitable fracture fluid should be compatible with the formation. It is crucial that the fluid transports proppants deep into the fracture while keeping them suspended. Fluids with an inherent viscosity will likely develop the fracture width necessary for proppants to be accepted. Additionally, it should have a low friction pressure loss and sufficient stability to retain its viscosity during treatment.