SimLith v.1 Drawing Lithological Columns in Excel

From time to time, there is a need to draw lithological columns with descriptions, here I developed an alternative to heavy softwares. It allows drawing lithology column in MS Office Excel without the hassle, and it is free.

SimLith Lithological Column Sample

SimLith Interface

Download: http://www.geologier.com/software

The features are:
1. It is light weighted, quick and depending on MS Office Excel only.
2. Customize the lithology fill pattern based on the Excel Fill Pattern
3. Customize the lithology width
4. Automatically generate the lithological legend list based on the drillhole/section input
5. The drawn lithological column (is grouped and) can be copied/pasted to other MS Office applications, and can be changed if needed.

How to Use the Program:
1. Open the SimLith Spreadsheet. If it asks you whether to allow the Macro, you select Yes
2. Input data in the lithological input section (from, to, lithology and description)
3. Setup
    3.1 Generate the lithology legend. This step allows you to generate the list of lithology included in the whole drillhole or section.

SimLith Lith List Generation

After it is done, you should see your lithology is updated in the Lithology Column and Lith Scale Column in the Legend Section. The Lith Scale col. is used to change the width for each of the lithology in the drawn column. If you want to keep the lithology the same width in the draw, you should keep them the same, otherwise, change them accordingly. It is recommended to assign numbers to the Lithological Scale from 1.

SimLith Legend Section

3.2 Generate the Legend, by clicking the 2. Legend (re)gene Button.

SimLith Generate the Lithological Fill Pattern (Legend)

After that, you should see lithological patterns are generated, radomly, for each of the lithology, in the col. of Fill Pattern. If the fill pattern is not desirable for some lithologies, you can change them by right click on the filled pattern, and choose "Format Shape". Then, at the fill pattern changing tool, change the forecolor and the fill pattern.

Change the Fill Pattern Step 1

SimLith Change Fill Pattern Step 2

3.3 If you want to change some other settings for the lithological col., you can change them accordingly. Parameters you can change include,

SimLith Parameters change

• zoomindex--Vertical zoom index, has to be a number
• Lith Descr Col.  No. (don't change)--the col. location of the lithological description, has to be a number
• Litho Des Col. Width--The width of the lithological description col., has to be number
• Litho Des Text Size--The font size of the lithological description, has to be number
• Litho Max. Width--The max. width of the lithological col., has to be number
• Litho Column line weight -- The line width of the lithological col., has to be number
• Depth From Col.--The depth from which you want the col. draw to start, has to be number
• Lith Descr Text Color -- Color of the lithological description in the draw, select from the drawdown list
• Lith Border Line Color -- Color of the lithological box border in the draw, select from the drawdown list

3.4 After you are happy with the settings, click 3. Draw lith Column Button. You can see the drawn lithological col. at the right.

SimLith Draw Lith Column 

SimLith Generated Lithological Col.

Q&A:

1. If I need to draw many drillholes, do I have to change the Fill Pattern Legend everytime? 

A: Not necessarily. If the drillholes share same lithology, then you set it up once. After you input the lithology in the lithology col., you go and draw the lith directly by click 3. Draw Lith Col.

2. Can I manually add in the fill pattern box?

A: No. The fill pattern box is created and linked to the lithology list generated.

3. Can I move the drawing all at once to other application?

A: Yes. The drawing is grouped into two groups, one is for the Lithology Col., and the other one is for the Lithology Description. Then, those two groups are grouped again into one.

If you want to break the group, right click on the drawing, and select ungroup. 

Ungroup the Drawing

VBA Macro: Clastic Sedimentary Lithology Interpreter based on Geophysical logs-Density and Gamma

The code is using geophysical gamma and density data to interpret the lithology. However, even in simplest conditions, other interpreting criterion will be required to make an accurate interpretation. So, the code and Macro provided here is for your reference, and I am not take any responsibility of you using this macro. BTW, the density and gamma logs have to corrected (no trends or tool errors or anything), otherwise the result looks like a joke...

Right, I am not a programmer, and this is something I came out in work and think might of help to some geologists. The code is quite lazy and there must be efficient ways to do this, and I will be grateful if you can offer some suggestions and help or ideas to improve the function/performance or the code, you can leave your comments here or email me. Also, if you have questions, please leave some words as well. 

What is it again? what can it do if anything at all?

Function: The purpose of the this marco is to interpret the lithology based on the geophysical logs (gamma and density) and the criteria you set for the common clastic sedimentary rocks, as Coal, Mudstone, Sandstone, Siltstone, Carbonaceous Mudstone, Overburden...

As shown in the below screenshots, it allows you to input the gamma and density criteria for each of the lithology, and also the OVB thickness, and the thin layer thickness to be merged which will be explained below. 

Mechanism: Three steps are taken in the code,

1. Interpret each line of the geophysical log based on the sampling interval (such as 0.01m per line) and assign a lithology name based on the density and gamma value of this sampling interval. Such as, in the interval of 100m to 100.05m, the density is 2 G/CC, and the gamma is 100 API, and you think it is sandstone, the sandstone is assigned to this line.

2. After the lithologies are assigned to the raw geophysical data, you will have thousands if not more of lines of lithology, but that is not what you want for the result. So, we combine then. Here, the code combines the lithology of intervals with the same lithology above and below of that interval. This will shorten the lithology list, but that is still too much. So, we process further.

3.  Consolidate/merge the very thin layers which has similar or very close lithology to the overlying or underlying layers, or where you think the lithology and underlying and overlying can be merged. Probably it is more reasonable/conservative to merge the spatially and lithologically close ones, such as merge the thin layer of mudstone into overlying and/or underlying siltstone, and siltstone into sandstone etc, not coal into sandstone.

Meanwhile, the step 2 and step 3 are executed sequentially and repeatedly for the resultant consolidated lithology list.