A new method using transient well testing to determine the in-situ absolute permeability of the formation when three phases of fluids are flowing simultaneously in the reservoir is presented. The method was verified through simulation using synthetic data and its applicability and practicality were confirmed through application to field data. Determining the absolute permeability over the reservoir scale using readily available transient testing data will have major benefits in accelerating history matching and improving reservoir performance prediction

A recently developed method (Kamal and Pan, 2010) to determine the in-situ absolute permeability under two-phase flowing conditions extended the applicability of transient well testing and has been adopted in commercial software. In this study:

  1. We extend the analysis method to determine the absolute permeability and fluids saturations when three phases are flowing in the reservoir. We show that an optimization procedure is needed to obtain the required results in this case.

  2. We show that the theoretical bases for the method presented to determine absolute permeability from transient tests under multiphase flow conditions are the same as those used in obtaining relative permeability relations from core analysis and predicting reservoir performance in reservoir simulation studies.

The method presented in this study uses surface flow rates, and fluid properties of the three phases. It also uses the same relative permeability relations used in the simulation models thus ensuring the same permeability values calculated from field data are used in history matching and predicting the performance of the reservoir. The method was verified by comparing the results from analyzing several synthetic tests that were produced by numerical simulation with the input values. Data from a deep water field were also used to test the practicality and validity of the method. For the field case, the method was verified by matching reservoir production and pressure using calculated absolute permeability. Excellent agreements were obtained for both synthetic and field cases.

Keywords:
flow in porous media, optimization problem, Modeling & Simulation, absolute permeability, fluid saturation, Fluid Dynamics, three-phase flow condition, flow rate, effective permeability, Upstream Oil & Gas
Subjects:
Reservoir Fluid Dynamics, Reservoir Simulation, Formation Evaluation & Management, Flow in porous media, Drillstem/well testing
Copyright 2015, Society of Petroleum Engineers
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