A procedure is presented for the simultaneous determination of capillary pressure and tail-end relative permeability from a continuous injection experiment at different flow rates. This is achieved through matching the experiment with numerical simulations. In our experimental setup, a core plug is placed between a water-wet and an oil-wet filter while fluid is injected continuously into the core. The resulting pressure drop over the core contains information on both the capillary pressure and the relative permeability of the displaced phase. With an optimisation procedure, built around a numerical simulator, these key reservoir parameters can be extracted from the measured differential pressure. The validity of the procedure is discussed and whether the capillary pressure and relative permeability curves obtained are unique is examined. Application of the procedure to sandstone, provides results which are in good agreement with those obtained with other techniques. The automatic matching procedure developed can, in principle, be applied to every experiment that can be simulated with a standard simulator. As an example, the calculation of the capillary pressure and tail-end relative permeability from equilibrium centrifuge data is discussed.

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