A porous material is a solid that is saturated by an interconnected network of pores filled with liquid or gas. It is an inorganic or organic cross linked or uncross linked containing pores of all sizes. The pore network is assumed to be continuous, forming two interpenetrating continua such as in a sponge. Examples of porous media range from porous silicon which is porous on the sub manometer scale to limestone caves and underground river systems on the kilometre scale. In this book, fractal structures are generated to model the structures of natural porous media. It also presents the fundamental theory of transient infinite elements, which can be used to effectively and efficiently simulate heat transfer and mass transport problems in fluid-saturated porous media of infinite domains, and addresses recent advances in the integrated modelling strategies of mass transfer and geo-mechanics in porous media.