A number of utilities are available to help management drillhole projects including: • Import/Export Drillhole Project – send a project to another user or archive.
This option enables all related project files including downhole colour patterns, section definition files, project data tables, surface files are copied to a single folder which can be zipped. Other users can import the project directly into their drillhole module.
• Save Project Workspace – the workspace created with this utility removes all reference to the hidden drillhole project files that are opened but not visible when a project is opened. This can cause problems if the standard MapInfo workspace space option is used as project files may reside on local drives.
• Subset Project – create a new drillhole project based on a selection from an
already existing drillhole project. All project tables are subsetted and saved to a new folder and automatically added as a new project to the Drillholes module.
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10 3D Drillholes
Drillholes
In order to view drillholes in Discover 3D the drillholes must be part of a drillhole project. Open a drillhole project in 2D using the Drillholes>Project Setup dialog and select the appropriate drillhole project from the pull-down list. The Discover
3D>View Drillholes option then allows the selection of the drillholes to display in 3D from a list of available drillholes: if collars have already been selected (either graphically in a map window or via a query), these will be highlighted in this dialog. Alternatively, the Open Discover Drillholes button in the 3D Window allows selection of the appropriate drillhole tables (collar, survey (optional) and downhole data) provided they are already part of a drillhole project. Once these have been opened, the Add Drillholes button displays the Drillholes Properties control dialog. This allows selection and appearance control of the desired drillholes for display in 3D, including downhole data display and labelling. The Drillholes
Properties dialog can be reopened by right clicking on a Drillholes branch and
selecting the Properties option.
Note The Open Discover Drillholes option provides no subsetting options; the entire
project will be brought into 3D, which may not be ideal for very large datasets (the user may experience reduced 3D rendering performance). In contrast, the
Discover 3D>View Drillholes option allows only the selected drillholes to be
displayed in 3D as a temporary drillhole project, which can be useful when examining only a portion of a very large dataset (better 3D rendering).
Exercise 10.1 Create a drillhole project using the Copper Hill database. View and label this
database in 3D.
Data Location: Training 3D\Drilling\ Project Files
1. Open the drilling dataset located in the above data folder within MapInfo,
and examine the tables. These typify a new field dataset, and need to be manipulated for use in the Discover Drillhole module:
- The DHcollars table needs to be mappable: use Table>Create Points
to set the projection as AGD66 Zone 55.
- The DHcollars table has an RL column with an arbitrary Z value
assigned, as is often the case for regional drilling where drillhole collars are unsurveyed. Use the Surfaces module Assign Values
from Grid option to populate the RL column with Z values from the
DEM_5m grid file.
- The DHassays table has no assays; these must be updated from the
assay lab’s assays_021103.csv file. First create the required assay fields (type float) in the DHassays table using
Table>Maintenance>Table Structure. Then import the csv file as a
native MapInfo table, and run the Discover Table Utilities>Multi-
Column update tool, linking the SampleID columns and the various
98 Encom Discover 3D Workshop Manual
Note Ensure that the Get Values from table is a native MapInfo table (i.e. it has a
.DAT file). Operating on a non-native table (eg a .csv or .txt file) will significantly increase the processing time, as MapInfo cannot index the table.
2. In Discover, create a new drillhole project called “Copper Hill” using this
dataset.
- Run the Discover > Drillhole menu, then Drillholes > Project Setup.
Click the New button, name the Project “Copper Hill” and click OK. Browse to the Project Files folder and click OK.
- Assign the DHcollars and DHsurvey files, and select the Downhole
Data Tables DHgeology and DHassays. Set the DEM_5m table as
the Topography Surface table. Assign the appropriate Spatial Columns, and tick ‘Down Dip is negative’. Click OK.
3. Select Discover 3D>View Drillholes. From the list of drillholes available,
choose the entire list to display the double arrow key. Click OK to display in the 3D window.
Note that options are available to load the entire dataset or subset a portion of a drillhole database to assist in loading time and improve 3D re-draw performance when working with large datasets.
Note Graphical selection of a drillhole subset is also possible within the Discover 3D
window using the Holes tab of the Drillholes Properties dialog. The graphical selection dialog incorporates individual, rectangular and polygonal tools as well as View Direction options (Front, Side and Top). Sub-setting of the dataset within the 3D environment will not improve re-draw performance. However this is a useful way to view particular spatial areas of a drillhole dataset.
4. Within the 3D window, double-click on the Drillholes branch in the
Workspace Tree to open the Drillholes Properties dialog. At the bottom of
the Appearance tab are a number of hole labelling and symbol options. Enable the Collar Label and Depth Label options, and set the Depth
interval to 25m. Press OK. Note that whilst rotating the 3D view, the labels
remain Facing the Viewer.
Note Labelling of large datasets consumes a significant amount of graphics memory,
and will reduce the speed of 3D rendering. In particular, depth labelling results in multiple labels per drillhole, and is therefore not recommended for large datasets (it also can result in a very cluttered view).
5. Return to the Appearance tab, and select the Collar Label button. Set the
pull-down to the right of the Style button to Fixed 3D. The resulting labels will be fixed in 3D space; their orientations can be modified via the direction and dip bezels at the base of the dialog.
6. To display both the hole name and total depth at the collar location, again
press the Collar Label button under the Appearance tab. In the top text field, start a new line (after the %HOLE_NAME% entry), and press the adjacent
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arrow to display a list of valid fields. Select the %HOLE_BOTTOM_DEPTH% and %UNITS% fields as below, and apply the changes.