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The goal ofmIt is to convert The log evaluation's O is anda*Rw? In the log evaluation's estimation ofRo(Water saturated formation resistanceivity) Not the core analysis versionRoOr the "true"Ro. This log analysis is used to determine the reservoir saturation.mIt is an internal log analysis parameter. It fails to produce RoIt is not suitable for use and is incorrect in the real world. Because the laboratory scale is cm, the scale of the Rt logged, which it will be used with, is metre, or possibly dm, the laboratory is not a good analogy for in-situ conditions. Log analysis "equations” assume that inputs came from the same piece, but they may not have if the inputs are different. SCAL is a perfect example of this. mLogging RtIn heterolithic facies.

Certain water zones (Sw100 from side-walls cuttings and the chromatograph) span a range O in rocks of similar rock types (similar O-k Crossplots). We have access to log data's actual Ro and m values - what we require. We ignore Nature's reservoir conditions m laboratory, and instead try to create reservoir conditions within the laboratory. Why? This faith in core data is a mistake.

Focus on the actual data used in the evaluation and consider the objectives of each step.

Saturation Exponent n.

Converting is the objective of n The log evaluation's value for Ro/Rt into the actual reservoir Sw. As heterogeneity grows, the log evaluations metre-scale estimate of Rt/Ro differs from the lab's cm-scale measurement. The n definition plot is used to determine the value of n. It is commonly found in core analysis reports. It shows that n is the slope of Log(Sw vs. log(Rt/Ro). This plot is typically populated with core data, but the Rt/Ro scale for the log data that will be used in the evaluation is not taken into account. Log analysis is prone to erroneous answers.

The n definition plot can work more efficiently if you consider the objective and concentrate on the data that will be used for the evaluation. This author uses sensible data to determine n. This is Not Unless we have the opportunity to deal with homogeneous "blockysand" at a metre scale, core data is only available at cm scale.

Do not be deceived into believing that you know the right answer for m or n because you have done core SCAL analysis. Think.

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