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TOC Analysis Module

PetrophysicsJuly 30, 2025

Purpose

The TOC Analysis modules provides several methods for estimating the total organic carbon (TOC) content of a system and convert it to a volume of kerogen.

Primary Outputs

The following curves are the primary interpretations made in this module.

Curve NameDescription
TOC_FINALFinal TOC result using method selected for zone
V_KERVolume of kerogen derived from the TOC_FINAL curve

Log tracks for TOC interpretationScreenshot showing the well log tracks for the TOC Analysis module.

Discussion

Users can make interpretation via several different methods. In general parameters can be set via drag and drop on log tracks or by typing parameters into the CPI Params tab. Most parameters and methods can be set on a zone-by-zone basis.

Several other curves are calculated en route to the primary outputs listed above. The table below lists some of the key results that you may want to compare among themselves.

Curve NameDescription
TOC_SCHMOKERTOC result from Schmoker method
TOC_SLOGRTOC result from Passey sonic method
TOC_DLOGRTOC result from Passey density method
TOC_NLOGRTOC result from Passey neutron method
TOC_VERNIKTOC result from Vernik method
TOC_FAUSTTOC result from Faust method
TOC_MOD_PASSEYTOC result from Modified Passey method
TOC_COMBINEDTOC result from average of twelve empirical Schmoker-like methods

In general when performing the interpretation it is best to identify the key properties in an inorganic shale interval and use those properties to set the key parameters for the methods of interest.

It is often useful to set the parameters for each of the methods to try and minimize the variance among methods. This will make it easier to change methods between wells if the data requires it.

The “Schlumberger method” for TOC to kerogen conversion has been reported to show good results from several clients.

An additional video for TOC interpretation can be found here.

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