An Integrated Analysis of Petrophysics, Cross-Plots and Gassmann Fluid Substitution for Characterization of Fimkassar Area, Pakistan: A Case Study

Abstract

Reservoir characterization is a process of describing various reservoir properties using all the available data to provide reliable reservoir models for accurate reservoir performance prediction. This process requires the use of proper methods for characterization to avoid many prominent errors in the prediction of reservoir performance. Fluid substitution is an important process which provides a tool for fluid identification and quantification in a reservoir. In the present study, petrophysical, cross-plot and Gassmann fluid substitution analysis is applied for the characterization of reservoir of Fimkassar area, Pakistan. The data used for this purpose consist of suite of wireline logs from two wells and laboratory data showing typical rock properties for water-saturated limestone. Our results show that cross-plot analysis performed in this study can provide a qualitative method for the identification of type (water or hydrocarbons) of fluid present within the reservoir. The results of Gassmann fluid substitution at Sakesar limestone level indicate variation in acoustic properties (velocity and density) at different water saturation levels which can be modeled in terms of synthetic seismograms and may help in determining future optimum well locations.