An Analysis on mCSEM Responses for Sandstone Reservoirs with Respect to Changes in Petrophysical Properties

Abstract

This study makes an analysis on marine controlled-source electromagnetic method (mCSEM) responses for various petrophysical properties of sandstone reservoir. It is necessary to consider sensitivity of mCSEM data to petrophysical properties of the reservoir for valid interpretation of mCSEM field data. For computing reservoir resistivity that changes in accordance with reservoir porosity, water saturation and resistivity of formation water, we used Archie's equation which is widely used for formation evaluation of sandstone reservoir. We obtain and analyze not only amplitude of electric field but also its normalized amplitude by using a three-dimensional mCSEM modeling algorithm. Furthermore, we study on relations between operation frequency and buried depth of hydrocarbon reservoir. The relative difference in mCSEM responses for a sand reservoir is more than 70% when the water saturation increases from 0.2 to 0.5.