Experimental Study: Investigate the Proppant Settling Velocity in Static and Dynamic Model Using High Viscosity Friction Reducer and Linear Guar
Authors: Biheri Ghith , Elmaleh Khaled , Imqam Abdulmohsin 
Published: September 2022

ABSTRACT:
In unconventional reservoirs, enhancing formation conductivities through hydraulic fracturing treatments can significantly improve the oil production of the wells. Fracture conductivity can be achieved by transporting and distributing the proppant across the fracture lengths. The primary objective of this study is to measure the fracture fluid viscosity and elasticity of HVFR and linear guar at room temperature (21°C). Secondly, this work evaluates the proppant settling across HVFR at 3 gpt and linear guar at 20 ppt concentration, using a static model and two mesh sizes (40 and 70 mesh size), where the mesh size of 40 was obtained using 40-45 mesh sizes, while 70 was taken using 70-80 mesh sizes. The final part of the study focuses on investigating the proppant transport through a dynamic model, where the measurements of proppant transport were conducted using different fracture fluids, flow rates, and injection points. The results showed that HVFR has better viscosity and elasticity than linear guar. Also, the results exhibited that HVFR can hold the proppant for a significant time in comparison to linear guar, despite increasing proppant size. The study provides comprehensive information about the settling velocity of the proppant using both fracture fluids (HVFR and linear guar), and how their rheology of viscosity and elasticity could govern the proppant settling velocity.

1. INTRODUCTION
Production from unconventional reservoirs using hydraulic fracturing techniques has recently received significant attention due to its ability to increase oil recovery (Ortega et al., 1996; Elturki and Imqam, 2020a; b; Khurshid et al., 2020). The permeability of unconventional reservoirs can even be reduced due to the deposition and precipitation of organic compounds, such as asphaltenes and waxes, during the production process and thus decrease oil production (Elturki and Imqam, 2021a; b; c; Mohammed et al., 2021; Elturki et al., 2022a; 2022b).Also, Analysis the injection and production rate (Unal et al., 2019) and evaluate the pressure effect on the fracture growth and fracture geometry (Awad et al., 2020; Eltaleb et al., 2020, 2021) is significant during hydraulic fracturing operations. Therefore, providing a successful proppant distribution inside the fracture networks to improve the formation conductivities is the main objective of doing hydraulic fracturing treatments. And to maintain the opened fractures after the hydraulic fracturing process, these proppant transport can be achieved by a reliable fracture fluid that has high rheology of viscosity and elasticity which allow to enhance the oil productivity (Elturki et al., 2021). Nowadays, several oil companies started to use high viscosity friction reducer (HVFR) instead of using polysaccharide such as linear guar or crosslinked gels because HVFR reduces hydraulic fracturing operations costs. HVFR also is an environmentally friendly alternative compared to traditional methods of using linear guar or crosslinked gels where it requires less water, reduces the chemical used by more than 30%, and reduces the on-site equipment footprint (Van Domelen et al., 2017; Dahlgren et al., 2018; Johnson et al., 2018). Additionally, HVFR helps reduce friction by more than 70% (Shen et al., 2019; Xu et al., 2019; Song et al., 2020; Hazra et al., 2020; John et al., 2021), which could lead to a decrease in surface pressure and may increase injection rates. Several experimental works were conducted to investigated HVFR capability; some of these studies focus on evaluate the rheology on HVFR (Gaillard et al., 2013; Hu et al., 2015, 2018; Aften, 2018; Shen et al., 2018; Biheri and Imqam, 2020, 2021; and Kurdi et al., 2020). The outcomes demonstrated that HVFR has good viscosity and elasticity in comparison with linear guar, and HVFR showed good rheology even at lower fluid concentration.