SIMULATION OF IMBIBITION PROCESS IN A CONSOLIDATED POROUS MEDIA

An extensive understanding of fluid flow in porous and fractured-porous media is very important for both a better exploitation of energetic resources (hydrocarbon, geothermal energy) and water and groundwater resources safeguard. The imbibition (an immiscible displacement process in which a wetting fluid displaces a nonwetting fluid, that initially saturates the porous medium sample, by capillary forces alone) represents an important phenomenon studied for several decades and in several research areas. In particular at present our interest is focused on capillary water rise, namely a process in which water enters into an unsaturated porous medium. Many analytical and numerical models have been developed and proposed in order to describe such phenomenon like, for example, the Washburn model that assume a piston-like displacement. The aim of this work is to implement a numerical model to simulate the capillary water rise in a rock core with known petrophysical properties. In particular with special attention on problems arising from sample sizes (scaling effect) and sample heterogeneity. For this purpose, following what reported in the work of Schembre et al, an input file, in free format, suitable for the commercial simulator ECLIPSE 100 (Geoquest, Schlumberger) version 2006.1 has been prepared. In order to evaluate the correctness of the response of the model (model validation), the simulated height of the imbibition front as a function of time has been compared with the commonly used Washburn equation, and, in a first analysis, the numerical model seems to work well. Obviously, owing to both the high degree of uncertainty by which many petrophysical rock parameters are known and the complexity of ECLIPSE itself, it has several hundred of Keywords, further work is necessary in order to use it as a quantitative tool.