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hello, good day for you.
can anybody give me an advice why does my calculation in water saturation is higher than water saturation from Side Wall Core (SWC)?

for additional information, i used Indonesia Method (Poupon-Leveaux).
and got Rw value from pickett plot in 100% water zone (zone is known from Drill Steam Test). than, turtuousity factor is 1 (a=1), M & N are 1.88 and 1.8 (form SCAL core).

but, when i calculated it, it's higher than the value from Core.

please do not mind to answer my questions, because i need this for my research project of undergraduate thesis.

you can answer in this post, or by email me at thegarda(at)yahoo(dot)com

thank you for your attention.

There are many possible reasons why your computed Sw is higher than that measured on the Sidewall Cores.
First, are you sure that the Sw measured on the SWC is correct?
The resistivity log can be affected by many things, such as borehole effects, environmental effects, invasion, etc.
Have you made the required corrections on the resistivity logs to try and get the true Rt of the formation?
Usually, the Deep Induction Resistvity log ILD tends to underestimate the formation resistvity, especially in highly resistive formations such as carbonates.
The ILD also has a relatively poor vertical resolution, which can underestimate the formation resistivity if there are thin beds or laminations.
The sidewall core measurements are point measurements, whereas the log readings are averaged over the vertical resolution of the logging tool, even though the standard log sampling rate is six inches per sample. Therefore, there may be an issue of different depth resolution in the two measurements, when comparing each other.
If there is microporosity, especially in carbonate formations, it can cause the resistivity log to read low, causing the computed Sw to be high.
The Indonesia saturation equation is meant to be used in clastic reservoirs and may not work very well in carbonates. Furthermore, it uses Effective Porosity PHIE and is highly dependent on the computation of Vshale.
Can you try some other saturation equations such as Waxman Smits (if you have SCAL data) or Juhasz (modified Waxman Smits equation) if you do not have SCAL data.
You can also try to compute Sw using a Saturation Height Function (such as Leverett J or Skelt Harrison method) if you have capillary pressure data and you know the Free Water Level to hang the SHF.

So far, the only reliable Sw measurement on cores is the Dean Stark method. Even then, you need to take precautions that the cores are not excessively invaded with the drilling fluid.
If the Sw measurements have been made on Side Wall samples, there is a big uncertainty on the water saturation measured.
Yes, it is true that the resistivity log responds to the fluid inside the formation. However, you need to remember that the borehole environment is filled with drilling mud which is conductive, unless it is oil base mud, and there is also invasion by conductive mud filtrate which affects the Induction Resistivity log. Therefore to get the true formation resistivity, or least an approximation of it, you need to correct the measured ILD for borehole effects and environmental effects.
If you are using the new generation resistivity logs, such as the Array Induction or Array Laterolog, they can be modelled to derive true formation resistivity.
I suggest that you make the necessary corrections on the ILD and try using the Indonesia Saturation equation to compute water saturation.
As you know, Sw (from Indonesia Equation) is dependent on many factors, such as porosity, m and n exponents, Rw, Vclay, etc.
Therefore, you need to ensure that you have done your best to estimate all these parameters.
In the end, you will have to consider the uncertainties on the measurements and derived parameters to give a range of water saturation.
It is quite common to have large differences between resistivity derived Sw and core measured Sw.