Evaluation of a New Capillary Pressure Equation Derived from History-Matching Core Flood Experiments

Capillary pressure curves are essential for understanding how fluids relate to each other in multiphase systems and for identifying their distribution in the contact area. Capillary pressure is frequently measured and fits into a mathematical equation for inclusion in simulation models. When modeling in conjunction with relative permeability curves, this requires the use of equations to anticipate acceptable values through a history-matching process. Several mathematical formulas have been suggested thus far for modeling capillary pressure. There are certain restrictions and difficulties in applying the suggested equations. However, it must be admitted that some of them fulfil the function and offer fairly accurate results compared to actual measurements. By providing a more controlled formula with the same precision as the previous equations, the aforementioned modeling application issues can be resolved. This will be a huge help to the industry. In this paper, a new modified capillary pressure equation is proposed, an extension of the well-known Brooks-Corey model. The aim of using this formulation is that different wettability conditions can be represented. This paper compares the accuracy of the direct determination of capillary pressure curves using our proposed formulation with a previous formula used by Foroughi et al. (2022). The calculations are performed on several laboratory experiments representing a wide range of formation wettability. History-matching processes are also applied to two different experiments to evaluate the proposed modification using a commercial black oil simulator and its associated automated history matching tool. Our extended formulation has been validated, addressing the difficulties associated with alternative capillary pressure formulas. Its advantage is that it is a more controlled formulae with the same level of accuracy as previous capillary pressure equations. The proposed equation overcomes the complexities encountered by the alternative capillary pressure formula in Foroughi et al. (2022). The application of the current capillary pressure model shows some implications that the resulting capillary pressure curves return a plateau at mid-saturations, where the gradient with saturation is zero. This contrasts with simpler Pc curves, which exhibit a constant gradient when derived from laboratory measurements. However, this difference in representation does not have a significant impact on the modeling performance of the experiments. Future research could concentrate on examining hysteresis loops and capillary pressure behavior over a broader range of medium wettability.