Pore network models represent continuous interconnected pore spaces by discrete networks of pores and pore throats. It is a fundamental technique in the sense that it allows pore-scale behavior to be studied. At the same time, the significant approximations that are made (to both structure and flow) make it much more computationally efficient than direct solution of the equations of motion. The main benefit of this approach is the ability to model much larger length scales than with streamline-scale techniques. For this reason, network modeling represents an essential bridge between rigorous streamline-scale modeling and large-scale continuum models.

The image shows a small section of sandstone and its associated network (a one-to-one mapping of the pore space). Networks are often depicted visually by a ball-and-stick structure. However, modern networks are described using rigorous geometric parameters, which allows for quantitative modeling of many important phenomena.