Percolation Modelling and Non-Newtonian Flows in Oil Reservoirs

Abstract

Abstract In this paper we had established the law for flow of viscous-plastic fluids in porous media with taking into account the inertial losses. Such rheological properties can be found in heavy viscous oils which contain components with high molecular weights. The obtained common relation between filtration velocity and pressure drop can be used for different applied simulations of heavy oil recovery from real reservoirs. It has been considered the asymptotic properties of established macroscopic flow law for small and large velocities, and also investigated the correlation between macroscale limiting pressure gradient and parameters of microheterogeneity of the medium. A good qualitative agreement between the theoretical results and the experimental data was obtained. These data was taken for oil conditions of Arlanskoe field (Bashkortostan, Russia). Introduction The non-Newtonian behavior of many kinds of oils is a well-known phenomena for the reservoir engineering practice. That is why the problem of studying of this phenomena was in focus of investigators for a long time. However, at the most of the works it was not discussed the question about association between non-Newtonian properties of the macroscale flows and the microstructure of the porous media. The new analytical percolation approach was developed at last time. This approach allows to analyze wide spectrum of the problems of the underground fluid dynamics and gives the new understanding of the relations between peculiarities of the processes on the microscale and macroscale. Specifically, this methodology can be used for the investigations of characteristics of non-Newtonian fluid flows in porous media. In the previous works the nonlinear law for the Newtonian fluid flow in porous medium had been obtained with taking into account the inertial losses for the joints of capillaries and the phase permeabilities of a medium saturated by viscous-plastic fluids had been defined. Here we designed the model which allows us to obtain the nonlinear flow law of Binghamian plastic with consideration of the inertial losses. Also we carried out the qualitative comparison between our results and the experimental data for Arlansloe oil field (Bashkortostan, Russia). The two-phase displacement model had been investigated, and the relation between limiting pressure gradient and the saturation of porous media had been obtained for the case of steady-state flow.