Petrophysical Evaluation of Low Resistivity Pay Zones in Clastic and Carbonate Reservoirs

Y.M. Al-Shobaili¹

Abstract

A petrophysical integration methodology has been developed to evaluate low resistivity pay zones in both thin carbonates and laminated sand-shale sequences. This technique utilizes information from porosity and resistivity logs along with additional data from formation pressure and down-hole fluid sampling analysis. Thin-bedded laminated reservoirs occur in many hydrocarbon zones. The technique described in this paper provides an alternative method for evaluating these formations and reduces uncertainty in water saturation calculations.

Petrophysical evaluation of hydrocarbons in some carbonate formations is often challenging due to heterogeneity of the host rock. Despite the significant impact this heterogeneity has on log measurements for hydrocarbon saturation calculations, the industry has generally extended the same interpretation models applied in sand-shale sequences to carbonates.

AAPG Search and Discovery Article #90188 ©GEO-2014, 11th Middle East Geosciences Conference and Exhibition, 10-12 March 2014, Manama, Bahrain