Analytical solution to pressure transient analysis in non-Newtonian/Newtonian fluids in naturally fractured composite reservoirs

Abstract During polymer flooding into the reservoir using shear-thinning non-Newtonian fluids, an interface exists between in situ Newtonian crude oil and injected solution. This paper examines application of well test analysis techniques to develop analytical solution non-Newtonian/Newtonian fluids with different flow index composite reservoirs for estimating boundary conditions such reservoirs. Mathematical models were presented solved analytically Laplace transform. The was inverted real domain Stehfest algorithm (Stehfest Commun ACM, 1970). Solutions obtained three that are infinite acting, constant pressure no-flow boundaries. New derivative type curves developed naturally fractured A general obtained, which is adaptable case fluid interface. Numerical examples used estimate radius investigation, power-law parameters curve matching Tiab’s direct synthesis technique.