Dual-phase flow in two-layer porous media: a radial composite Laplace domain approximation

Abstract

The main purpose of this work is to present an interpretation method for injectivity test in a two-layer reservoir that can be extended to a multilayer approach, based on new analytical solutions to the well pressure response. The developed formulation uses a radially composite reservoir approach and considers that the water front propagation may be approximated by a piston-like flow displacement. The reservoir is assumed to be laterally infinite and properties such as permeability and porosity may be different in each layer. The solutions were developed in the Laplace domain and then inverted to real domain using the Stehfest Algorithm. The proposed formulation was then validated by comparison with a numerical flow simulator. Results showed a good agreement between the numerical simulator and the analytical model. Also, a sensitivity study was done by comparing the results of different scenarios varying oil viscosities and injection flow rate to assess how these properties affect the pressure and pressure derivative profiles.

Impact of Crossflow and Two-Phase Flow on Gas Production from Stacked Deposits

“…29 Mastbaum et al proposed a method for testing the two-phase flow capacity in two-layer reservoirs in the Laplace domain by analytical solutions of well pressure responses. 30 Xu et al derived a mathematical model for oil and water co-production from an arbitrary multilayer. 31 Zhou et al evaluated interlayer interference during the co-production process in an offshore oilfield through a theoretical model considering reservoir heterogeneity and two-phase flow.…”

“…Several numerical models have been established to study the gas production from multilayer stacked deposits in one or two lithologies . Mastbaum et al proposed a method for testing the two-phase flow capacity in two-layer reservoirs in the Laplace domain by analytical solutions of well pressure responses . Xu et al derived a mathematical model for oil and water co-production from an arbitrary multilayer .…”