Well Test Analysis in Multi-layered Reservoirs Using Numerical and Analytical Simulations

The analysis of well test data in multilayer reservoirs is usually a challenging problem due to the complexity of interlayer flow within the reservoiror across the wellbore. These problems are mainly due to insufficient data from the flow quantity of the individual layers into the wellbore. Moreover these kinds of tests usually could not be analyzed during shut-in periods. The analyzer which is used for this kind of analysis should be verified first, to achieve this purpose some attempts are made and finally a practical interpretation methodology is achieved. For this ٢ purpose a numerical simulation model is developed to design synthetic models of multilayered reservoirs. Different scenarios are of permeability and skin contrasts between layers are designed and the simulation responses are exported to an analytical well test package and the tests areanalyzed as actual tests. It was found that, if the individual layer flowpotential is not included in the analyses the permeability and skin contrasts between layers may affect the analysis results and in some cases bigerrors may be obtained. We proposed some suggestions to make a systematicanalysis of multi-layered systems to simulate the transient well test data using numerical and analytical models. This methodology can beused to evaluate the well productivities in less time and numerical simulation.