Analysis of Pressure Transient Test of Non-Newtonian Fluids in Infinite Reservoir and in the Presence of a Single Linear Boundary by the Direct Synthesis Technique

Abstract

Abstract Non-Newtonian fluids are very common during drilling, fracture operations and enhanced oil recovery processes. When a reservoir contains a non-Newtonian fluid such as those injected during polymer flood or the production of heavy oil, well test data cannot be interpreted using Newtonian fluid flow models. The resulting analysis would be erroneous because non-Newtonian fluids behave rather differently. These results suggest the need for a thorough study of the behavior of non-Newtonian fluids in the reservoir and also a new look at the flow of those fluids in porous media. This study presents an interpretation technique for pressure behavior of non-Newtonian fluid flow in a homogeneous reservoir without type-curve Matching. The inclusion of a no-flow and/or a constant pressure line is also investigated. First, the TSD (Tiab's Direct Synthesis) technique was applied for analyzing the pressure behavior of a well located in (1) an infinite reservoir and, (2) near a linear boundary where wellbore storage and skin effects were considered. The analysis required the generation of type-curve sets for different wellbore storage and skin values. A step-by-step procedure is presented for the calculation of the reservoir parameters: the permeability/viscosity ratio, wellbore storage coefficient, skin factor and the distance to the nearest boundary without the use of type-curve Matching. The procedure is illustrated by an example. Introduction There is a vast amount of information in the literature on elastic properties of polymer solutions, viscoelasticity and viscoelastic flow of non-Newtonian Fluids in porous media. Although many fluids in nature are Newtonian, there are many fluids of practical importance that do not even approximate a linear relationship. There are known as non-Newtonian Fluids. The use of those fluids is not new in the petroleum industry. They have been used for many years as fracturing agents and drilling muds and in some enhanced oil recovery processes. Even though their use is not new, the subject of transient flow of non-Newtonian fluids in porous media is very new to well testing.