New nonlinear correction method of oil-water relative permeability curves and their application

The relative permeability curves from laboratory measurement only represent the flow behavious of core sample and commonly do not accord with the real flow behaviors, thus they need to be corrected through history matching. However, the process of history matching is time-consuming and labor-intensive. The current study introduces a new method to correct the relative permeability curves based on the nonlinear optimization theory and accurate experimental endpoint. Based on the assumption that the relative permeability satisfies the exponential function, the theoretical water cut-recovery curve (fw-R) is fitted to the actual fw-R curve to obtain relative permeability curves. The new method requires fewer parameters and is simple and faster. Application of the new method to Turpan-Hami Oilfield WENXI 3 block shows that the the corrected relative permeability curves fit better with the calculated relative permeability through history matching, indicating this correction method is feasible. The corrected relative permeability curves are representative and in good shape. The theoretical water cut-recovery curves obtained by using the new method are in good accordance with the real curves.