Hi,

petrophysical measurements are a practical way to provide values of connectivity of pore space. Mercury injection in core samples gives estimation of porosity and permeability. The difficulty is to obtained undisturbed samples of the formation. Core sampling during drilling process remains is a solution but remains expensive.

The tortuosity can be defined as the ratio between the distance actually travelled by the fluid through the porous media divided by the macroscopic lenght (straight line from the inlet face to he outlet face). the pore connectvity index is used to describe the network potentially used by the fluid. The lattice gives informations for further permeability models. Some authors define the connectivity index as probabilistic measure which quantifies the likelihood of an established connection between two subspaces of porous medium.

Dear Francois,

Thanks a lot. The latter definition for PCI approximates what I expect. Could you please suggest me a few articles to refer (including methods).

Thanks Francois for a very concise and complete answer.

I agree but not always those core plugs exist...

There is not a concept named 'Pore Connectivity Index' in petroleum context. And tortuosity factor is the deviation of pore connections from direct line. we can guess pore connectivity by measuring effective porosity, amount of connected pores, in other words, effective porosity can be a measure of pore connectivity.