Advances in well testing for solution-gas-drive reservoirs

This work presents procedures for constructing relative permeability curves from well-test pressure data obtained at a well producing a solution-gas-drive reservoir. The effects of wellbore storage on the analysis of multiphase flow pressure data are also discussed.;It is shown that the relative permeability curves can be constructed from values of effective oil and gas permeabilities computed from well-test pressure data and application of nonlinear regression analysis techniques with Standing's correlation as the model function.;These computational procedures are also considered for heterogeneous solution gas drive systems and can be applied when the initial reservoir pressure is greater or equal to the initial bubble-point pressure.;The effect of wellbore storage on the analysis of pressure drawdown data obtained at a well producing a solution-gas-drive reservoir is also investigated. It is shown that effective oil permeability as a pointwise function of pressure can be computed directly from the measured values of the flowing wellbore pressure provided the sandface oil flow rate is measured and incorporated into the analysis. For cases where the sandface flow rate is measured, a new computational procedure for estimating oil situation as a function of pressure is presented.;The effect of wellbore storage on the analysis of pressure buildup data obtained in a solution-gas-drive reservoir is also examined. Based on a superposition equation, new computational equations for obtaining rough estimates of effective oil and gas permeabilities as pointwise functions of pressure from the measured values of the shut-in wellbore are presented.