APPLICATION OF TDS TECHNIQUE TO MULTIPHASE FLOW

Although, the radial difussivitity equation has been solved for a single-fluid phase flow, in some cases more than one phase flows from the reservoir to the well; therefore, the single-phase solution has been previously extended to multiphase flow without losing a significant degree of accuracy. Practically, there exist two ways of dealing with multiphase flow: The Perrine method, Perrine (1956) which basically replaces the single-phase compressibility by the multiphase compressibility so that each fluid is analyzed separately using the concept of mobility. The other one is the use of pseudofunctions which have been found to be the best option. The TDS technique has been widely applied to a variety of scenarios. It has been even tested to successfully work on condensate systems with the use of pseudofunctions, Jokhio, Tiab and Escobar (2002). However, equations for estimation of phase permeability, skin factor and drainage area has not neither presented nor tested. In this article, we present new versions of a set of equations of the TDS technique to be applied to multiphase flow following the Perrine method along with a previously presented way of estimation of the absolute relative permeability. We successfully applied the proposed equations to synthetic and field examples.