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 |
Screenshot of the well log tracks in the porosity module.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
DCA: Type well curves
In this video I demonstrate how to generate a well set filtered by a number of criteria and generate a multi-well type curve. Before starting this video you should already know how to load your data and create a DCA project. If not, please review those videos. Type well curves are generated by creating a decline that represents data from multiple wells.
DCA: Loading Production data
In this video I demonstrate how to load production and well header data for use in a decline curve analysis project. The first step is to gather your data. You’ll need: Production data – this can be in CSV, Excel, or IHS 298 formats. For spreadsheet formats you’ll need columns for API, Date, Oil, Gas, Water (optional), and days of production for that period (optional). Well header data – this can be in CSV, Excel, or IHS 297 formats.
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?