Tag Archives: lithology
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
Creating Batch PDF Output for Your LogPlot Logs
If you want to create PDF output of a bunch of logs created with LogPlot7, you can automate this using the Log | Batch Compile menu command. Here are the steps I’ve taken to set this up. NOTE that this requires that you have a PDF program, such as Adobe Acrobat Pro, or any of the free PDF printers (PDF995, CutePDF, etc. – see RockWare forum postings regarding these) installed as a printer in your Windows system.
1. First, be sure you’re using a build of LogPlot7 that is 7.4.81.107 or newer.
2. Set up your PDF printer as the default printer in LogPlot, using the program’s File | Setup command. (On some systems you may also need to set up the PDF printer as default in the Windows Control Panel before launching LogPlot.)
3. You can set up the page size for the printer as well.
Setting up the PDF Printer Page Size
4. Set up the PDF printer driver to NOT prompt for PDF file names, and set the output folder to the same folder where the data files reside. I’ve attached an example of what my Acrobat Professional screen looks like, though your version or your PDF printing software may be different. Note that this is an important step so that you won’t be prompted for each PDF output file name.
PDF Print Settings
5. Then, select the Log | Batch Compile menu option in LogPlot.
6. Click the Add button, and in the Batch Editor window define the name of the data file, the log design, scale, and other compile settings. Be sure Print is selected, and be sure the Save as LPT file is also selected and a name defined. (The PDF file name will be based on the LPT name you define here.)
7. Click OK when you’re done, and you’ll see this log’s items listed in the batch window.
LogPlot Batch Window
8. Repeat for additional files, though you might start with just a handful to get the hang of it and to be sure the PDF files are actually being created.
9. Save your batch at some point, using the Save button in the Batch Compile window. At a later date, you can use the Load button in this window to load an already-saved batch listing.
! Note: the BTC file that is created is an ASCII XML-type file. If it is easier for you to modify the BTC file directly to add other logs, you certainly may do so, just be careful about the XML syntax.
10. To run the batch, just click the Go button at the bottom of the Batch Compile window. LogPlot should load the selected DAT file, compile it into the selected LDFX file using the indicated settings, save the requested LPT file, and print to PDF, storing the PDF file in the requested folder. It will repeat this process for each item listed in the batch.
11. If you want to append all of the PDF’s into a single file, you can use Adobe Acrobat’s File | Combine | Merge Files menu option.
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
A Trick for Modeling Lithologic Unconformities
If you are trying to create a lithology model composed of horizontal beds that have been eroded and then overlain by a layer of soil, fill or even material such as concrete, you’ll often find that the horizontal lithoblending algorithm incorrectly places this upper layer of material below the sediments in some places.
One solution is to use some newer tools in the Lithology menu to create two separate Lithology models that can then be combined. Here is an explanation of how this works.
Let’s start with the “Soil” layer at the top of the model. First, it is important to assign a G-value to the Soil Lithology Type that is lower or higher than all the other material types. In this case, the Soil material has been assigned a G-Value of 2. All of the other material types have been assigned values between 3 and 8.
In the Lithology modeling tree menu, choose to create a model titled “Lithology Warped”. Warp the model based on a grid that represents ground surface elevations, and turned off the “Randomize Blending” option to avoid interfingering of the soil and sand below.
While the representation of the sediments is probably not reasonable, I think that the soil layer at the top of the model looks much better in the diagram below than it does in the diagram above.
Next, create a model of just the flat lying sediments (in this example, the model is called “Lithology Sediments.mod”). When creating this model, turn the Randomize Blending option back on, the warping option OFF, and tell the program to limit the model to just materials with G-Values between 3 and 8.
As you can see in the diagram below, RockWorks has included everything except for Soil in this model.
Finally, use the Solid à Filter à Replacement Filter tool in the RockWorks Utilities, to insert the Soil in the warped model into the sediments model.
The diagram below displays this final model in a cross-section.
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.