Water Saturation Computation Using Resistivity Ratio Method

The attached presentation is an actual field example, illustrating how the resistivity ratio method is used to compute water saturation in a gas-bearing shaly carbonate (limestone) reservoir.
This method is not something new. It is mentioned in some of the basic log interpretation books.
It is an alternate method of calculating water saturation without using formation porosity together with a cementation exponent m, as is usually done in water saturation equations.
As I have mentioned many times in the past, what I am presenting now is based on basic principles and fundamentals of petrophysics.
It is not something new or innovative.
It is meant for young petrophysicists and other oil and gas professionals who are interested to learn about basic petrophysics.
It is not meant for experts and experienced petrophysicists.
So, please don’t jump on me.
The objective of this case study is to show how the simple resistivity ratio method can be used to compute water saturation in reservoirs, like carbonates, where the cementation exponent m is either unknown and possibly variable.
I hope that this will be of interest to some of my young connections.