Dual Pore Network Model of Electrical Resistivity for Carbonate Rocks

摘要

We develop a model which explains the non-Archie behavior of carbonate rocks with multi-scale structure. Non-Archie behavior in such rocks is qualitatively related to the degree of connectedness(percolation)of different water fractions,namely water residing in networks comprising pores of very disparate scales(micro-porosity and macro-porosity). To this end,we investigate here a previously reported dual pore network model(D-PNM)which allows for heterogeneous matrix(micro-porosity)properties and variably-connected macro-porosity. By varying the relative amounts,geometric properties and degree of connectedness of microporosity and macro-porosity,we are able to stylistically reproduce all documented deviations of the resistivity index from Archie behavior.