The Effect of Heat Transfer and Polymer Concentration on Non-Newtonian Fluid from Pore-Scale Simulation of Rock X-ray Micro-CT

Abstract

Most of the pore-scale imaging and simulations of non-Newtonian fluid are based on the simplifying geometry of network modeling and overlook the fluid rheology and heat transfer. In the present paper, we developed a non-isothermal and non-Newtonian numerical model of the flow properties at pore-scale by simulation of the 3D micro-CT images using a Finite Volume Method (FVM). The numerical model is based on the resolution of the momentum and energy conservation equations. Owing to an adaptive mesh generation technique and appropriate boundary conditions, rock permeability and mobility are accurately computed. A temperature and concentration-dependent power-law viscosity model in line with the experimental measurement of the fluid rheology is adopted. The model is first applied at isothermal condition to 2 benchmark samples, namely Fontainebleau sandstone and Grosmont carbonate, and is found to be in good agreement with the Lattice Boltzmann method (LBM). Finally, at non-isothermal conditions, an effective mobility is introduced that enables to perform a numerical sensitivity study to fluid rheology, heat transfer, and operating conditions. While the mobility seems to evolve linearly with polymer concentration in agreement with a derived theoretical model, the effect of the temperature seems negligible by comparison. However, a sharp contrast is found between carbonate and sandstone under the effect of a constant temperature gradient. Besides concerning the flow index and consistency factor, a master curve is derived when normalizing the mobility for both the carbonate and the sandstone.

Numerical Simulations of Polymer Solution Droplet Impact on Surfaces of Different Wettabilities

“…The simulations (in axisymmetric geometry) were performed in parallel using the domain decomposition method. The pressure implicit with splitting of operators (PISO) algorithm was used to calculate the pressure, while the evolution of the conformation tensor was solved using a preconditioned bi-conjugate gradient technique; further details on implementation and discretization can be found in our previous work in References [10,34,37]. The convergence criteria set for the pressure, velocity, and conformation tensor fields were of the order of 10 −6 .…”

“…Very recently, Antonini et al [4] performed a comprehensive study of the impact of drops on hydrophobic and superhydrophobic surfaces so as to help select the appropriate substrate for a given application. Complex fluid droplet impact has gained attention recently due to the key role it plays in applications ranging from 3D printing, polymer light-emitting diode technology, and lab-on-chip technology, to biotechnology for protein engineering [5][6][7][8][9][10]. The liquids involved in these processes are likely to exhibit non-Newtonian properties, such as viscoelasticity, which results from adding flexible polymers to solvent liquids.…”

Pore-Scale Modeling of the Effect of Wettability on Two-Phase Flow Properties for Newtonian and Non-Newtonian Fluids

“…The power-law model is adopted to reflect the fluid employed in EOR polymer flooding, which exhibits shear thinning behavior in line with the work in [11]; the typical values are χ = χ 0 = 10 −2 Pa.s n and n = 0.81. The two-phase flow VOF model describes and discriminates the fluid in a given numerical cell through the phase fraction (α).…”

“…The complexities of the pore space microstructure and two-phase flow simulations make computation of flow properties very challenging. The numerical techniques used to conduct pore-scale simulations can be classified into two categories: (i) pore-network modeling [7] and (ii) direct modeling, which includes the finite difference method [8], the finite element method [9], the finite volume method [10,11], and the lattice Boltzmann method (LBM) [1]. The pore-network model (PNM) has been preferred over direct simulation to predict petrophysical properties due to its simplicity.…”

“…In order to gain meaningful physical insight into the flow behavior, this study adopts direct modeling, after demonstrating the limitations of PNM. Recently, direct pore-scale simulation of single-phase flow addressing the computation of the permeability has been performed for both Newtonian and non-Newtonian fluids [11,16,17]. An interesting experimental in situ assessment of static contact angles at the pore scale has been performed in [18] with Newtonian fluids.…”