The benefit of local saturation measurements in relative permeability estimation from centrifuge experiments

The standard method for estimating relative permeabilities from centrifuge experiments is to match the production data. This study examines under what conditions local saturation measurements (in addition to production data) can improve the estimation of wetting- and nonwetting-phase relative permeabilities. Synthetic experimental data were obtained through simulation. Three distinct sets of wetting- and nonwetting-phase relative permeability curves at low and high mobility ratios were used to construct the experimental data. The relative permeabilities were then history matched through nonlinear regression using either local saturation and production measurements or only production measurements. Local saturation in conjunction with production measurements can improve the estimation of relative permeabilities from centrifuge experiments. The most significant improvement is in the prediction of the wetting-phase relative permeability at low mobility ratios (e.g., less than 5). For gas/oil systems (with high mobility ratio), the wetting-phase (oil) relative permeability was accurately estimated in all cases using an initial guess based on Hagoort's method with or without local saturation data. Prediction of the nonwetting-phase relative permeability is still difficult under some conditions.