Porosity Interpretation Module
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 Name | Description |
|---|---|
| PHIT | Total porosity |
| PHIE | Effective 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 Name | Description |
|---|---|
| ND_POROSITY | Neutron-Density porosity |
| DEN_POROSITY | Density porosity |
| SON_POROSITY_SIMPLE | Wyllie sonic porosity |
| SON_POROSITY | Wyllie sonic porosity with compaction factor |
| SON_POROSITY_RHG | Raymer-Hunt-Gardner sonic porosity |
| GD_POROSITY | Density porosity using deterministic grain density method |
| MM_POROSITY | Rhomaa-Umaa porosity |
| PECKING_POROSITY | Prioritized neutron-density, density, sonic porosity |
| MINV_POROSITY | Mineral inversion-based porosity from grain density |
| MINV_POROSITY_STRICT | Sum of fluids from mineral inversion |
| PASS_THROUGH_POROSITY | User 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 Map | Description |
|---|---|
| AVG_PHIT | Average total porosity for the selected zone |
| AVG_PHIE | Average effective porosity for the selected zone |
| PHIT_NET_RES | Average total porosity for the selected zone in intervals flagged as net reservoir |
| PHIE_NET_RES | Average effective porosity for the selected zone in intervals flagged as net reservoir |
| PHIT_NET_PAY | Average total porosity for the selected zone in intervals flagged as net pay |
| PHIE_NET_PAY | Average effective porosity for the selected zone in intervals flagged as net pay |
For more interpretation advice, please see this tutorial video.
Related Insights
Quick Start Module
Purpose The Quick Start module is designed to help users quickly set dozens of common parameters by selecting a handful of basic options from dropdown menus. Parameters There are three parameters that are set on a zone-by-zone basis and two parameters that are set on a full-well basis. These are as follows. Discussion The parameters are linked to what are called named_defaults in the software. These are collections of defaults that can be set through assigning a single parameter.
Sample data to get started
Need some sample data to get started? The files below are from data made public by the Wyoming Oil and Gas Commission. These will allow you to get started with petrophysics, mapping, and decline curve analysis. Well header data Formation tops data Deviation survey data Well log data (las files) Production data (csv) or (excel) Wyoming counties shapefile and projection Wyoming townships shapefile and projection Haven’t found the help guide that you are looking for?
NMR Interpretation Module
Purpose The NMR interpretation module allows users to calculate porosity, bound and free fluids from the measure T1 and T2 distributions from NMR tools. Primary Outputs Discussion In oil and gas well logging, the $T_2$ distribution is used as a high-resolution "map" of the formation's pore system. While a standard porosity tool tells you how much fluid is there, NMR tells you where that fluid is trapped and whether it will flow.