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.
Making Log Calculations in a Flow
This articles provides an overview of how to use a Flow to before basic log calculations. To do this, the following Flow tools are used: LogInput >> Bring the log data into the Flow LogMath >> Perform some calculation LogOutput >> Writes the log data to a new log database. There can be as many LogMath tools added to a flow as one would like, and they can be added to existing Flows ushc as a Log Clean-up Flow. The LogMath tool is extremely flexible.
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?