Tutorial: Display Multiple Stratigraphy Logs in a 2D Cross-Section

Estimated time: 6 minutes.

In this lesson, you will be creating an image representing the stratigraphy data in multiple logs in the Samples project, selected along a multi-log cross section trace. Straight-line (not-modeled) correlation panels will be included.

1. Click on the Striplogs menu, and then click on 2-Dimensional | Section.
   
2. Establish the section options: These are found in the left pane of the Stratigraphy Section window.
   • Plot Striplogs: Check this.
     
     
   • Borehole Spacing: Expand this heading if necessary and be sure that this is set to Distance between Collar Locations. (In your own work, the Uniform Distance option can be handy if you have lots of clustered wells.)
     
     
   • Plot Correlations: Check this box, and expand this heading. (In your own work, if you wanted a log section only you could leave this un-checked.)
     • Stratigraphy: Click in this button to select stratigraphic correlations. Expand this heading.
     • Colors Only: Choose this as the fill style.
     • Correlation Type: Set this to Axis to Axis.
       
       
   • Hang Section on Datum: Uncheck this.
     
     
   • or Plot Surface Profile: If you completed the borehole map section of the tutorial (jump back), insert a check in the Plot Surface Profile option. This is used to display a selected surface in the cross section plot. If you DID NOT complete that lesson, leave this un-checked.
     • Grid Model: Click to the right and select the .RwGrd file representing the ground surface, named surface.RwGrd and click the Open button.
     • Line Type: Click here to set the line style to red, medium thickness.
     • Smoothing can be set to 1.
       
       
   • Show Faults: Uncheck this.
     
     
   • Perimeter Annotation Options: These options determine text and lines that will plot around the perimeter of the section. Click on this button to view the options; the factory defaults should be fine.
     ! In your own work the Intended Vertical Exaggeration Factor can be very helpful for good diagram proportions if you have a large, flat study area and will stretch your cross sections for readability.

   • 

   • Create Location Map: Check this item. This will create a small map that shows the location of the section "cut" in the study area. Expand this heading to change:
     • Append Map to Profiles and Sections: Check this option. Expand this heading and be sure the Size setting is set to Medium.
     • Display Map as Separate Diagram: Uncheck this option.
       
   • Legends: Click on the Options button to the right.
     • Stratigraphy: Check this item. Uncheck all of the other legend options.
       
       
   • Truncate: Uncheck this.
     
     
3. Establish the striplog options: Now you need to set up how the logs within the cross section will look. Click on the 2D Striplog Designer tab, to the right.
   
   
   
   The program will display the 2D log designer window. This window has three main sections:
   • The left pane is where you choose what type of data is to be displayed in the logs (the Visible Items).
   • The upper-right pane is where you see a Preview of the active log items. You can drag the items to adjust their relative placement.
   • The lower-right pane displays specific Options for the Visible Item that you click on.

   a. Choose the items you want to see in the logs by inserting a check-mark in the following items in the Visible Items section of the window:

   • Title: The drill hole name will plot above the logs.
   • Depths: The logs will be labeled with depth tick marks and labels.
   • Stratigraphy: The logs will contain a column illustrating formation depths with graphic patterns and colors.
   • None of the other options, including Text, should be checked.

   b. Adjust the arrangement of the visible log items: You should see four items in the upper Preview pane: title, depth bar, log axis, and stratigraphy patterns.

   • Practice clicking on an item, holding down the mouse button, and dragging it to the left or right in the preview.
   • Try getting the items aligned in the following order:

   

   ! Note that the log axis is always activated. It acts as the "anchor" point for the log - it's the axis that will be placed at the actual log location in the diagrams. The log title is always placed atop the axis.

   c. Check the options for each visible item by clicking on the item's name in the listing; its options will be displayed in the Options pane.

   • Click on the Stratigraphy item.

   

   • Click on the Column Title option.
   • Delete any text that's displayed to the right for the column title.
   • Click on the setting displayed to the right of the Width item, just above the title.
   • In the prompt type in:  1   
     ! All log item sizes are expressed as a percent of the dimensions of the project, so the width of these logs will be about 1% of the project dimensions.
     
     
4. Next, pick the boreholes to display.
   • Click on the Section Selection Map tab.
     
     
     
   • If you don't see the section trace pictured below, follow these steps; otherwise skip to step 5:
   • Click on the Clear button at the top of the panel-picking window. The program remembers your cross section traces from session to session; this will clear any old traces from memory.
   • Next, locate the hole titled "DH-17" (toward the upper-left) and click on it. It will be marked with a red "X".
   • Locate hole "DH-03" southeast of "17" and click on it. A line will be drawn between the holes.
   • Locate hole "DH-21" southeast of "03" and click on it.
     ! If you make a mistake, click the Undo button to undo the last pick or the Clear button to clear the slate for starting over.
   • Click on "DH-40," "DH-41," and "DH-07" continuing the cross section southeastward through the project area.
   • You should see a trace like this:

   

    

5. Rules & Filters: These are displayed in the pane along the far right of the window. We'll experiment only with the Stratigraphic Rules for this lesson.
   • Infer Partial Units: Be sure this is checked. This tells RockWorks to try to determine a missing top or base depth for a formation based on overlying or underlying strata which are defined.
     • Infer Missing Contacts: Be sure this also is checked. This sub-option can plot the contacts for partial units midway between the available top and base.
   • Insert Missing Units: For this pass, leave this option unchecked. We'll return to it in a moment.
   • Create Pinchouts within Linear Correlations: Leave this option off, also.
     
     
   • Date / Time Filtering: off
   • Spatial (XYZ) Filtering: off
     
     
6. Process: Click the Process button at the bottom of the Stratigraphy Section window when you are ready to create the section plot.

The program will create strip logs of each of the selected borings using the selected settings. The logs will be spaced proportionally to their distance from each other on the ground.
It will draw straight-line correlations between like horizons in adjacent holes and fill them with the background color specified for the formation in the Stratigraphy Types table.
In addition, it will create a map that displays the location of the section slice within the study area and append it to the cross section.

The completed log section will be displayed in a RockPlot2D tab in the Options window.  RockPlot2D is where 2-dimensional ("flat") maps, sections, and other diagrams are presented.

7. Resize the window: Grab the lower-right corner of the plot window and drag it upward and to the right, to resize the window so that it’s longer horizontally than vertically.  The program will rescale the image within the resized window. (You may need to click the Zoom Out button if it does not rescale automatically.)
   
   
8. Note that there is a hole in the middle of the section, where no correlation has occurred for the Leadville Limestone (light blue) in DH-21.

If you move this window out of the way and click back into the Borehole Manager, click on DH-21, and click on the Stratigraphy button, note that the Leadville Ls. is missing from this hole.

9. Click back into the plot window, and now:
   • Insert Missing Units: Insert a check in this option, in the Rules pane along the right. With this turned on, the program will assume that formations which are missing entirely at a contact can be pinched out at that location. The program will insert them into proper sequence, with zero thickness, during the creation of the diagram. Note that this rule does not affect the data in the database, but instead adds the extra control when the data is processed for diagram generation.
   • Click the Process button again to regenerate the diagram.

Now RockWorks has filled in the missing panel.

10. Adjust the Vertical Exaggeration: The VE notation, in the upper toolbar, is still shown at "1", meaning that the section's length (horizontal) and elevations (vertical) are being plotted at the same scale. In your own work, you may find that your distance and depth units aren’t so agreeable, and you’ll need to apply some stretch to your images to get a good look.
    1. You can use either the Stretch button to fill the screen at whatever scales, or
    2. You can adjust the vertical stretch specifically by clicking on the VE button (or choosing View | Vertical Exaggeration) and typing in a desired value.
       
       
11. Reposition the Stratigraphy Legend:  In RockPlot2D you have the ability to edit the entities in the plot window.
    1. Click on the Edit arrow in the upper-left corner. 
    2. Click on the stratigraphy legend, on the right side of the diagram. When it is selected, you'll see handles on each corner.
    3. Click on the legend and drag it to another location in the window. Release the mouse button when it is positioned to your liking.
    4. To resize the legend, click and hold one of the corner handles and drag so that it is smaller or larger.
    5. If you like, you can double-click on the legend to see the options available in the Legend Attributes window.  There are settings that control the legend size, position, and appearance.  Click OK to close the Attributes window.
       
       
12. Undock this cross-section into a stand-alone window by clicking the Undock button:
    
    
13. Save this image for later work in the ReportWorks program, where you can create a nice layout of the log profile and the section location map. With the section displayed in the new RockPlot window, choose File | Save, and type in the name: straight strat section    and click Save. The program will save this image in its own ".Rw2D" file format.
    
    Minimize this plot window for the time being, by clicking on the button in the upper-right corner.
    
    
14. Close the original cross-section plot window, by clicking in the Close button in the upper-right corner. You do not need to save the changes.
    
    
15. If you’d like to do the ReportWorks lesson at this time, click here.
    
    
16. Otherwise, continue on with the stratigraphy model lesson, below.
    
    

See also:

• RockPlot2D tutorial
• Hole to Hole Sections versus Profile Sections

Displaying Multiple Logs in a 2D Hole to Hole Section

  Back to Stratigraphy menu     |    Next (3D Stratigraphic Model) 
 

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