Prediction of Proppant Settling Velocity in Fiber-Containing Fracturing Fluids

Abstract

Hydraulic fracturing is the main stimulation method in the development of oil and gas fields. It is helpful to predict the fracture support effect during fracturing by calculating the settling velocity of particles in the fracturing fluid. Experimental research shows that fibers mixed into the fracturing fluid can improve the performance of suspended sand. In this study, fiber was considered a solvent in the fracturing fluid, and the constitutive model of the fiber-containing fracturing fluid was modified according to the fluid rheology. From the analysis of the mechanical behavior in the fibercontaining fluid, the settling velocity of particles slowed down because of some reasons. First, the viscosity of the fiber-containing fracturing fluid increased significantly. The other mechanism is the resistance mechanism of the fiber acting on the particle. The apparent viscosity was fitted based on the rheological model and the measurements. Then, the drag coefficient model of the settling particles was built according to the rheological data of the fibrous fluid. A semi-empirical model was developed to predict the terminal settling velocity through research on dynamics. By characteristic analysis of the results, we found that the fiber on the settling velocity is closely related to the concentration of the base fluid. This prediction model is suitable for the base fluid and fiber-containing fracturing fluid, and the average relative difference between the prediction model and measurements was acceptable.

Simulation and solution of a proppant migration and sedimentation model for hydraulically fractured inhomogeneously wide fractures

“…where ρ f g(1 + C(η − 1)) is the additional gravity component arising from the difference in density between proppant and fracturing fluid, which is only available in the longitudinal direction, η = ρ p ρ f . The proppant settling velocity is given by (Bai and Li, 2023;Kong et al, 2015;Li et al, 2024;Pan et al, 2018;Roostaei, 2017;Sahai and Moghanloo, 2019;Singh et al, 2022) (Table 1):…”

“…), different proppant types (grain size (Sahai and Moghanloo, 2019), sphericity (Zhang, 2017), density (Hao, 2018;Li, 2018)), different carrying fluid viscosities (Anschutz et al, 2023;Zhang et al, 2021), different injection flow rates (Liang et al, 2018;Liu et al, 2019;Zhang et al, 2023b), different fracture types (eg. even-wide fractures (Liang et al, 2018), elliptical shape fractures (Zhu et al, 2023) or complex fractures (Li et al, 2024;Qu et al, 2023;Xiang and Li, 2023)) were also investigated in the indoor tests to obtain the proppant accumulation distribution under various conditions, which then served as a reference for optimization of the parameters of the hydraulic fracturing in the field, Bai and Li (2023) and Zhou et al (2023) did research on the friction and settling characteristics by indoor tests to provide parameters for numerical model. However, the model equipment of indoor tests during hydraulic fracturing does not fully simulate the actual situation of a fracture morphology in the subsurface.…”