A new methodology for analyzing non-Newtonian fluid flow tests

Abstract

Abstract Conventional treatment of oil flow in porous media assumes that oil is in the typical range of flow velocity and pressure, and it behaves as a Newtonian fluid. This assumption, however, may not be accurate, especially for heavy oil. It is also not accurate in modeling injection behavior for fluids such as fracturing fluids, or polymer fluids for secondary recovery of oil. The literature contains articles that formulated and presented solutions of the posed fluid flow problem. When trying to apply the proposed solution methodology, the limitations of those techniques became apparent. Many authors have already pointed out the inapplicability of the presented techniques and suggested some corrections. Moreover the presented techniques are not valid for non-Newtonian fluids that have a power law index ( n ) greater than 0.6. In this paper we examine the solutions presented in the literature showing their limitations. We will examine the mathematical reasons for the problems and demonstrate rigorously that these (published) analysis techniques are impractical not only for real world problems but also for simulated data. Our in depth analysis explains away the problems analysts have had with the existing methodology. We also present a new reliable methodology for determining reservoir properties. The new methodology was tested on six real field data and two simulated datasets. The examples showed that the previously presented methodologies under-predict the permeability by at least 40%.