Tag Archives: Block Model
New Video Using Multi-Seam Coal Data to Demonstrate RockWare Command Language (RCL) Scripting
New Video: Using the RockWare Command Language (RCL) to Automate Cross-Section Generation
New Version of RockWorks16 (2013.8.8) Available
Click image to download latest version.
Master Directory of RockWare YouTube Videos
The YouTube playlists have proven to be somewhat cumbersome, so we have created a hyper-linked master index that makes it easier to find content. Check it out …
RockWare YouTube Video Index URL: http://www.rockware.com/rockworks/revisions/rockware_videos.htm
Layering Profiles and Cross-Sections in RockWorks
RockWorks allows you to create cross-section and profile diagrams of a variety of types of data – such as modeled lithology, stratigraphy, aquifer, geochemical or geophysical data, fractures, etc. It can be very helpful to layer these profiles to determine, for example, the spatial relationship between a contaminant hotspot and the stratigraphic layers, or your water levels and the lithologic environment.
I’ll describe here an easy way to pop one profile onto another – in this example overlaying a benzene profile on top of a stratigraphy profile.
1. Create your two profile diagrams using the same annotation settings and the same profile slice. This assures that the profile panels will have the same coordinate range. I find it helpful to arrange the two profile windows on my screen, one above the other, so that they are both accessible.
Arrange both profiles on your screen so they're both visible.
2. With the RockPlot Edit Arrow tool activated, click on the I-Data profile contours to select them. (Note the red selection handles in the panel corners in the upper image.) Type Ctrl+C to copy this layer into memory.
Click on the I-Data profile color contours to select that layer, and copy it to the clipboard.
3. Click in the Stratigraphy profile window and type Ctrl+V to paste the I-Data profile into this diagram.
Paste the I-Data panel onto the Stratigraphy profile
4. Double-click on the I-Data layer you just pasted into the combined diagram to adjust the minimum contour level and transparency, so that the stratigraphic layers will be visible in the background.
Adjust the minimum contour level and/or transparency.
5. Click OK to close the Colorfill Attributes window.
Now you can see the stratigraphic profile in the background.
6. If you like, you can copy /paste the I-Data color legend in to the combined diagram. Use your mouse to resize/rearrange the legends as desired.
Combined Stratigraphy and Benzene Profiles
Exporting Lithologic Surfaces to DXF
As RockWorks view the world, lithology materials are not necessarily layered – they can repeat within a single borehole and may be inconsistent in sequence across the project area. As such, RockWorks uses a solid modeling process, rather than surface-modeling, to create lithology models, with the 3D nodes or voxels assigned a material type and represented in the 3D viewer as color-coded blocks.
Lithology Model in RockPlot3D
This presents a challenge, then, for users who wish to view lithologic SURFACES as plan-view contour maps, or in 3D, or exported to CAD.
In RockPlot3D you can access the lithology model’s Options window and filter the display for the desired material type, or range of types. Here is the above model filtered to display the Soil voxels only.
Lithology Model Filtered for Soil Only
This can be exported to DXF, but note that you’ll be getting all of the blocks representing that material. (Shown here in black and white for contrast purposes.)
Lithology Model Soil Voxels Exported to DXF
If you need a surface rather than blocks, RockWorks also has tools which will fit a surface to the uppermost elevations or the lowermost elevations of a rock type in a lithology model. These are in the Lithology | Superface (Top) and Subface (Base) menus. Here is an example of the same soil lithotype extracted as a surface (upper elevations), and displayed in RockPlot3D and then exported to DXF.
Surface Representing Top of Soil, Displayed in RockPlot3D
DXF Surface Representing Top of Soil
Computing Aggregate Reserves for a Site with Two Isolated Carbonate Units
This paper describes how to use RockWorks to compute total economic reserves for a site that includes two carbonate units: an upper limestone and a lower dolomite, separated by a shale unit. It involves creating separate I-Data models using the Stratabound filter, combining the models, and checking them against the observed log data.
Link to original paper: http://www.rockware.com/assets/products/165/casestudies/6/9/computing_aggregate_reserves.pdf
Introduction
The purpose of this study is to compute the total economic reserves for a site that includes two carbonate units; an upper limestone and a lower dolomite separated by a shale unit. Quality analyses have been obtained at one-foot intervals within the carbonates. The following diagram depicts a typical log showing the lithology, stratigraphy, and aggregate quality.
Figure 1: Typical log depicting aggregate quality (bargraph on left), stratigraphy (patterns in center), and lithology (subdivisions within stratigraphy)
Step 1. The Problem
Modeling the rock quality en-masse is problematic because the node values would include the quality values for both the limestone and the dolomite. The following diagrams depict a solid model based on the rock quality and a stratigraphic block model. Notice how the rock quality (I-Data) model interpolates quality values where there is no corresponding carbonate.
- Figure 2: Problematic “Bulk” Rock Quality Model
Compare the rock quality model with stratigraphy model below and note how quality values are interpolated where there is no carbonate.
- Figure 3: Stratigraphic Model
Compare this stratigraphic model with bulk rock quality model above and note how quality values were interpreted within overburden (light yellow) and interburden.
Step 2. The Solution
The solution to this problem is to use the “Stratabound” option within the I-Data / Model menu. Two rock-quality models were created; one for the upper limestone and another for the lower dolomite.
In the example below, the I-data model is confined to points and nodes within the Hanford Limestone unit.
Figure4: Hanford Limestone Rock-quality Model
In this example, the I-Data model is confined to points and nodes within Shuller Dolomite.
Figure5: Shuller Dolomite Rock Quality Model
Step 3. Combining the Models
The next step involved adding the two models together and removing all voxels with a quality value less than 50 (the minimum acceptable quality).
Figure6: Fence diagram depicting combined rock-quality models for upper limestone and lower dolomite.
Figure 7: Block Model depicting voxels with a quality value greater than 50.
Figure 8: Block model depicting zones from previous model in which the thickness for any single contiguous ore zone is more than 6 feet thick for any given column.
Figure 10: Block model depicting zones from previous model in which the stripping ratio is less than 1.2. This area represents a good place to start mining in order to gain the highest return on investment.
Step 4. Checking the Model
The final, and most important step, is to create a 3D log diagram, combine it with the final ore model, and examine the data to see if it make sense.
- Figure 11: 3-Dimensional Lithology/Quality Logs Combined With Final Ore Model.
Figure 12: Enlargement of area around highest-ROI ore depicting lithology and quality logs.
Step 5. Conclusion
By combining the preceding approach with increasingly more tolerant filter cutoffs, it is possible to create a mining strategy that will yield the highest return on investment from the onset.