Global Mapper v25.0

Solid Rock 3D model - Subsurface mapping of various strata

I have a few hundred drill holes that I want to use to create a subsurface model.  The core logs are a my source of information and are in excel.  I can format anyway necessary for GM to read the files, but so far I have classified and color coded 6 main categories of subsurface strata.  These main 6 are what I wish to use to visualize and map subsurface layers, having classified them out of a thousand petrographic/lithographic/geologic descriptions.  

Currently, the format of the holes in excel is something like this:
Hole # From To Code
85-1 0 9.5 1
85-1 9.5 10 6
85-1 10 21 2
85-1 21 22 3
 
I have a heading with location, hole ID, starting altitude.  The codes 1-6 I want to display as different colors at corresponding depths.  

After this is accomplished, I want GM to fill in the gaps between the drill holes and generate substrata layers.  I appreciate any advise and help that you can provide.

Answers

  • geomannie
    geomannie Global Mapper User Trusted User
    Hi Marshall

    I would say that GM is not the best tool for doing what you want but it will allow you to create a series of stacked 2D layers which you can view as a 3D image.

    What you need to do is to create a grid for each layer. For example Code 1 you need to create file as follows using all your wells taking the base of the layer as depth.

    X        y             Depth   Well Name
    Xcord1 Ycoord1   9.5      85-1
    Xcord2 Ycoord2   10.5    85-2
    Xcord3 Ycoord3   11.5    85-3
    etc.

    Once you have created the file in Excel, save to text file format and use the file, open generic text file import option. In the top left of the import dialogue tick the "elevation grid from 3D point data" (see example image). Make sure that "Treat 3rd coordinate value as elevation" is ticked. In the next dialogue, I suggest that you accept the defaults but its worth playing with the "loose-tight" slider to get a good looking result.

    You should now have a grid (surface) file.

    Repeat for the other layers, giving you a stack of surfaces.

    You can also open one of your text files as points only (make sure that the include attributes is ticked) so that you can post the hole locations.

    Once you have al your surfaces created, you can display in 3D. In the 3D Configuration options, tick the "Draw Multiple Surfaces" option to on if you want to see how they relate to each other.

    I hope that this is clear.

    Cheers





  • Thanks for the pointers, although I was hoping that there was some other way.  

    If I didn't want to generate a grid surface, but rather only display the series of drill holes with different colors at various depths?  
    For a single drill hole I want several colors to display depending on which strata are intersected.  
    Does each strata section need to be treated as a separate line with its own attribute (color code) or can I somehow have GM recognize and color different sections of a drill hole ( line) based on my current core log format?



  • geomannie
    geomannie Global Mapper User Trusted User
    Hi Marshall

    Understood. AFAIK GM will not do what you want. I know of no facility to display wellpaths/well data in 3 dimensions or cross-section.

    However, I know of a number of software packages that will pretty much do exactly what you want but most are expensive. You might look at Rockworks https://www.rockware.com/product/overview.php?id=165, not that I have used it myself, but the described funtionallity looks good and the price is low compared to similar products. The website suggests a free version with limited utility. It might be worth a look.

    I personally use IC http://www.lr.org/en/services/software/ic.aspx but the annual maintenance on that alone is several times the cost of a single Rockworks licence. A very nice package however.


  • Thanks Geomannie.  You're my new best friend.  
    I haven't had a chance to use specific geologic or mining software because of the reason that you mentioned:  cost.  Until now I've done quarry/mine design on autocad and lots of GIS data sets on Globalmapper.  Unfortunately, programs are designed for rather narrow functions and applications and are quite expensive... mine design software for mine design, geologic mapping and core programs for geology.  

    The minimal workflow I need to do doesn't justify the licensing cost.  It seems that I'll probably stick to autocad or sketchup and Globalmapper.  


  • geomannie
    geomannie Global Mapper User Trusted User
    Answer ✓
    Hi Marshall

    I am delighted to have a new best friend!

    For what its worth I have downloaded Rockware and maybe the free version will do what you want. Unfortunately it a learning curve and I haven't plumbed the depths to be sure.

    Good luck with your project.

    Cheers

    Bob