Estimating Multiphase Flow Properties Using Pressure and Flowline Water-Cut Data from Dual Packer Formation Tester Interval Tests and Openhole Array Resistivity Measurements

Abstract

Abstract Multiphase flow and production cuts are affected significantly by relative permeabilities under reservoir conditions. Yet their in-situ determination is practiced only in isolated cases, and these have used array resistivity logging. Although wireline dual-packer formation-testers provide direct flow tests, analysis thus far has been confined to the determination of single-phase permeability and anisotropy. In this paper, we present a methodology to integrate the formation tester pressure and water-cut measurements with openhole array resistivity measurements to obtain relative permeabilities of oil and water. It has been demonstrated previously that the filtrate invasion process, although uncontrolled, contains quantitative information of the fractional flow curve. The sampling process is similar; it is described by the multiphase/multi-component flow equations for which the initial condition is set by the invasion process. Geometrically, while the invasion process is largely cylindrical, the sampling process is not. To combine the two, we parameterize the invasion problem in terms of multiphase flow properties and drilling conditions, and carry out a simulation exercise, including generation of resistivity logs. The fractional flow parameters obtained, by matching the observed resistivity logs are then used for modeling fluid sampling with a formation tester. Comparison of the simulation results with the observed water-cut and pressure data allowed for further refinement of the relative permeability curves. A field example of the application of the above methodology will be discussed.