摘要:The present work focuses on the determination of absolute permeability in an oil reservoir whose pressure is under the bubble point. The simulation of the reservoir and well with the simultaneous flow of oil and gas is performed using the Eclipse100 software. The main purpose of the simulation is to obtain pressure build-up tests for two reservoir systems, as the well testing technology requires the shut-in period, which increases the costs of the real well production cycle. In the first simulation it is presumed that the well is not damaged, having the skin effect equal to zero, while in the second one, the skin effect of the well in the same reservoir is 9,44. The aim is to compare the results of the pressure build-up test analysis for both cases. In each case, permeability is firstly calculated using four methods, given by different authors. The theoretical background and the process of obtaining the required results are given for each approach. Results are compared with the permeability as determined by the pressure transient analysis, using the Saphir software, for both the ideal and the damaged well. Differences in results are presented and discussed. Conclusions can be applied to real reservoir systems with the multiphase fluid flow in the porous media.