Computation of polymer in-situ rheology using direct numerical simulation

Estimating polymer in-situ rheology is important for estimation of displacement pressure gradients and injectivity in the reservoir. In the following study, different models used to quantify the shear-to-flux correction factor are compared by using direct numerical simulation in 3D real rock images. We found that the models developed based on capillary bundle approach are not able to predict accurately in-situ rheology and microstructures of a rock sample can influence in-situ rheology. A novel approach is suggested to provide a more accurate prediction of in-situ rheology by adjusting appropriately bulk power index of the Carreau model before applying the correction factor. The pore scale simulations have revealed that the key parameters of porous media influencing in-situ rheology are pore aspect ratio and inaccessible pore volume.