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Porosity Interpretation Module

PetrophysicsJuly 30, 2025

Purpose

The Porosity Interpretation module provides several methods for determining the total and effective porosity.

Primary Outputs

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

Curve NameDescription
PHITTotal porosity
PHIEEffective porosity

Discussion

Porosity can be calculated via several different methods and the user can set the method and respective parameters on a zone-by-zone basis. The porosity calculation for each method, whether selected or not, is calculated and available for display. The references for these curves are given in the table below.

Curve NameDescription
ND_POROSITYNeutron-Density porosity
DEN_POROSITYDensity porosity
SON_POROSITY_SIMPLEWyllie sonic porosity
SON_POROSITYWyllie sonic porosity with compaction factor
SON_POROSITY_RHGRaymer-Hunt-Gardner sonic porosity
GD_POROSITYDensity porosity using deterministic grain density method
MM_POROSITYRhomaa-Umaa porosity
PECKING_POROSITYPrioritized neutron-density, density, sonic porosity
MINV_POROSITYMineral inversion-based porosity from grain density
MINV_POROSITY_STRICTSum of fluids from mineral inversion
PASS_THROUGH_POROSITYUser specified methodology

When performing your analysis remember:

  • When using the porosity from the mineral inversion remember to select either mineral inversion porosity or mineral inversion porosity (strict) options.
  • Make sure to adjust the clay porosity to a value suitable for the reservoir being analyzed.
  • Adjust the maximum porosity when working in areas with higher porosity to avoid accidentally restricting values.

For performing a QC of the results, the following maps should be evaluated:

QC MapDescription
AVG_PHITAverage total porosity for the selected zone
AVG_PHIEAverage effective porosity for the selected zone
PHIT_NET_RESAverage total porosity for the selected zone in intervals flagged as net reservoir
PHIE_NET_RESAverage effective porosity for the selected zone in intervals flagged as net reservoir
PHIT_NET_PAYAverage total porosity for the selected zone in intervals flagged as net pay
PHIE_NET_PAYAverage effective porosity for the selected zone in intervals flagged as net pay

For more interpretation advice, please see this tutorial video.

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