Badhole ID & Repair Module
Purpose
The Badhole ID & Repair Module enables users to flag and repair washout for the bulk density, neutron, sonic, and photoelectric factor curves based on user criteria. This module also comprises options for flagging coal and salt and for de-spiking curves.
Primary Outputs
The following curves are the primary interpretations made in this module:
| Curve | Description |
|---|---|
| gr_final | Final GR curve after all repair, despiking and normalization |
| sp_final | Final SP curve after all repair, despiking and normalization |
| rhob_final | Final RhoB curve after all repair, despiking and normalization |
| nphi_final | Final Nphi curve after all repair, despiking and normalization |
| dt_final | Final DT curve after all repair, despiking and normalization |
| pe_final | Final PE curve after all repair, despiking and normalization |
| resd_final | Final ResD curve after all repair, despiking and normalization |
| badhole | Flag for badhole intervals |
| salt_flag | Flag for salt intervals |
| coal_flag | Flag for coal intervals |
Screenshot showing badhole module and associated avg_gr_final grid.Discussion
Users can choose what curves badhole will be flagged and repaired for. By default the bulk density and photoelectric factor curves are evaluated. Users can also activate it for the sonic and neutron curves as needed.
As badhole should not typically be flagged and/or repaired in salt and coal intervals, if those lithologies are present the user should first select the general option to enable salt and coal flagging and then specify zone-by-zone if salt or coal is expected.
Recommendations include:
- When working across large areas consider using caliper rugosity instead of caliper to identify badhole as caliper will vary based on well design.
- When flagging coal and salt use the check boxes in the zonal parameters to turn on the flagging for each zone as required.
- Repair via MLR (multi-linear regression) or RF (random forest) uses and auto-ML that builds and tests several combinations of models to perform an optimal repair.
Results can be QC'd using the built in grids and cross-sections. The cross sections have names such as "RhoB Repair QC" and similar. The grids for the following should be inspected:
| Grid | Description |
|---|---|
| avg_gr_final | Average GR value for the zone |
| avg_rhob_final | Average RhoB value for the zone |
| avg_nphi_final | Average Nphi value for the zone |
| avg_resd_final | Average ResD value for the zone |
| avg_dt_final | AverageDT value for the zone |
| avg_pe_final | Average PE value for the zone |
Additional videos can be found here:
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?