Complex fluids with visco-elastic rheology for applications in oil & gas industry

Abstract

<h2>Abstract</h2> During the oil and gas recovery from subsurface, the recovery efficiency is mainly limited by two factors: pore-scale trapping resulting in irreducible hydrocarbon saturations and bypassing because of limited sweep efficiency due to rock heterogeneity, viscosity contrast and viscous instabilities. In order to improve the sweep efficiency, hydro-soluble polymer solutions with Non-Newtonian rheology are applied. The difficulty is in predicting the in-situ effective viscosity in Darcy-scale flow in the porous medium, based on bulk rheology provided for instance by shear rheometers (Berg and van Wunnik, 2017). Most of the relevant polymer systems, however, also exhibit viscoelasticity which can lead to elastic turbulence during flow through porous medium (De et al., 2022a). Here we show progress on the fundamental side, how to visualize the respective pore scale flow fields and understand the fundamental origins using a system that contains one single pore throat (Eguagie et al., 2020) and multiple pore throats and its effect on residual oil saturation (De et al., 2022b). In addition, we demonstrate how we numerically simulate the flow of viscoelastic fluids in porous medium and characterize elastic turbulence (De et al., 2022c).