Efficient and accurate estimation of permeability and permeability anisotropy from straddle-packer formation tester measurements using the physics of two-phase immiscible flow and invasion

The new methodology introduced in this paper interprets formation tester measurements acquired with wireline straddle-packer tools. It incorporates the physics of two-phase, axi-symmetric, immiscible fluid flow to simulate the measurements, and is combined with a rigorous nonlinear minimization algorithm for history matching purposes. Comparable inversion approaches have been recently introduced in the open technical literature This paper describes the successful application of a novel methodology to estimate permeability and permeability anisotropy from transient measurements of pressure acquired with a wireline straddle-packer formation tester. Unlike standard algorithms used for the interpretation of formation tester measurements, the methodology developed in this paper rigorously incorporates the physics of two-phase immiscible flow as well as the process of mudcake buildup and invasion. The effects of supercharge, skin, and convective transport of salt are also explicitly included in the estimation algorithm.