Petrophysical Parameters Curves’ Calculation for Non-conventional Reservoirs’ Modeling and Characterization

Abstract

The quantitative petroleum reservoir analyses’ topic is one of the biggest challenges facing geo-modelers. The difficulty lies in the fact that the constructed model depends on many empirical Archie’s law parameters such as tortuosity factor (a), cementation exponent (m), and saturation exponent (n). The most used methodology of choosing the appropriate set values of (a, m, n) is the trial/error technique. The parameters values’ sets are calculated empirically based on core data taken from different wells. The main drawback of this method is that these petrophysical parameters are not constant all over the reservoir section and are very variant in non-conventional reservoirs. The objective of this study is to provide curves of the petrophysical parameters (a, m, n) from petrophysical logs based on new equations. The new equations are based on relating tortuosity as a function of the sonic log and other basic logging curves (Gamma Ray, Neutron-density). Then, the calculated curves are used in constructing a more accurate non-conventional reservoir model. The obtained results have been compared to the conventional interpretation where a, m, and n are taken constants for all reservoir sections. Moreover, the obtained results are validated through core data and MDT tests in Algerian Southern non-conventional reservoirs.