Using Spontaneous Imbibition And Mercury Intrusion Porosimetry To Investigate The Effect Of Pore Structure On Fluid Migration Within Porous Media

Abstract

Much research has been conducted to investigate the property of fluid (water/oil/gas) migration in different types of porous media, and the knowledge of pore structure (including pore geometry and pore connectivity) plays an important role in this research. This dissertation will characterize the pore structure of different porous media (including building materials and natural rocks) by using spontaneous imbibition and mercury intrusion porosimetry (MIP). A new approach to deriving effective permeability of building materials using imbibition experiments is provided. Spontaneous imbibition is an important process in oil/gas production and its rate could affect oil/gas recovery rate significantly. As a result, this study performs spontaneous imbibition experiments using two types of imbibing fluids (water/n-decane) on the reservoir rocks to investigate their imbibition behaviors. Also, directional spontaneous imbibition is conducted on Barnett shale samples because of their layered characteristics and wettability information is indicated from these imbibition experiments.MIP has been successfully applied to characterize the pore-throat size distribution of porous media for several decades, and several important parameters, including permeability, gas diffusion coefficient and tortuosity, are derived from the resultant pore-throat size distribution in this dissertation. Our results indicate that the median pore-throat diameter (d50), which is defined as the pore-throat diameter corresponding to 50% mercury saturation during MIP measurement, plays an important role in both gas diffusion and spontaneous imbibition processes.