Litholgy model & I-Data intersection

[Daniele]

I've built a lithologic solid model with materials G1 and G2. I've a Surface map and different coloured map (if a material is present the value is set =1 , otherwise the value is set =0 ) obtained from Solid -> Booleand Conversion and Solid -> Solid to Grid Tools: one for G1, one for G2 and another one with both G1 and G2.

I add some I-Data: I set value =0 for not contaminated sample, value =1 for contaminated sample.

I plot a coloured map of the contaminated area.

How can I do to get the contaminated area matching with the lithology information?

I could only get contamination matching materials regardless of the contaminated lithology.

I would like to associate the contamination to the lithology.

In the attached PDF scheme the red area at the botton of the page is contaminated: but how can I get information about the source of contamination (G1 or G2) whithout plotting Multi log map with I data?

Thank you.

Daniele

[Alison]

I agree with Tom that this needs to be done at the solid model level (you wouldn't be able to get this type of information from the 2D grids you've created).

You could also create a Boolean contamination model composed of 0s and 0.1s. If you add that to your lithology model, the lithology model values will be shifted up by 0.1 in areas of contamination.

Regards,

Alison

[Daniele]

Thank you for your answers, but I'm still in trouble.

I've already followed what you suggested me, but I could't get what I'm looking for.

I choose Solid -> Model & Model and multiply between a Lithological solid model with boolean values (1 for material G1) and a I-Data contamination solid model with boolean values (1 for contaminated sample) with same xyz and node spacing. Then I made a surface map with Solid -> Convert -> Solid to Grid.

In the resulting map I get the material G1 matching the contamination related to G1 AND G2 (where G2 and G1 are BOTH present).

This issue arise when I've G1 AND G2 BOTH present. How can I separate contamination for G1 and G2 when they both are present?

Regards,

Daniele

[Alison]

Danielle,

You should now have a model composed of lithology values ONLY where you have contamination (in areas of no contamination, you have values of 0).

You should now be able to following the steps you followed previously to determine where you have contaminated G1 and contaminated G2. From what I remember, you converted your solid lithology model to boolean models for both G1 and G2, converted the boolean models to grids, and then added the grids together to determine where you have both G1 and G2.

If I'm incorrect about exactly what you want to do here, please let me know.

Thanks,

Alison

[Daniele]

Danielle,

You should now have a model composed of lithology values ONLY where you have contamination (in areas of no contamination, you have values of 0).

That's ok.

You should now be able to following the steps you followed previously to determine where you have contaminated G1 and contaminated G2. From what I remember, you converted your solid lithology model to boolean models for both G1 and G2, converted the boolean models to grids, and then added the grids together to determine where you have both G1 and G2.

If I'm incorrect about exactly what you want to do here, please let me know.

I don't have contaminated G1! Neither G2! I only have contamination (which refers to G1 or G2) and solid model (or boolean model) for G1, G2 and both G1 and G2.

[Alison]

Danielle,

I can send you some more specific instructions, but first, could you confirm that you have the following solid models:

1. A lithology model composed of numerical values representing various lithology types, including G1 and G2.

2. A solid model composed of concentration values representing a contaminant plume that intersect both lithology types G1 and G2.

If you do not have both of these models, then please let me know.

Thanks,

Alison

[Daniele]

Danielle,

I can send you some more specific instructions, but first, could you confirm that you have the following solid models:

1. A lithology model composed of numerical values representing various lithology types, including G1 and G2.

2. A solid model composed of concentration values representing a contaminant plume that intersect both lithology types G1 and G2.

If you do not have both of these models, then please let me know.

Thanks,

Alison

Yes you are right.

[Alison]

Great, please try following these instructions:

1. Convert your contamination model to a boolean model through the Solid --> Boolean Operations --> Boolean Conversion tool. You should now have a model composed of 1s where the concentration exceeds your cutoff value, and 0 where it does not.

2. Multiple your lithology model by the boolean concentration model through the Solid --> Math --> Model and Model Math tool. This will create a model composed of lithology values where contamination exists, and values of 0 where it does not.

3. Use the contaminated lithology model to create two new boolean models through the Solid --> Boolean Operations --> Boolean Conversion tool. You'll now have two boolean models showing you where you have contaminated G1 and contaminated G2.

4. For each contaminated lithology boolean model, create a grid through the Solid --> Convert --> Solid -> Grid tool. As before, use the "Z = Highest G-Value" Conversion Option. You'll end up with one grid for each contaminated lithology type composed of 1s where the contaminated lithology types exist, and 0s where the contaminate lithology type doesn't exist.

5. Finally, add the two grids together to determine where you have contamination in both G1 and G2.

If this still doesn't make sense, then please go ahead and send me both MOD files so that I can take a look (alison@rockware.com).

[Daniele]

Thank you for your support.

What I was looking is the Soldid -> Math -> Model (lithology model) x Moldel (boolean contaminant model).

As you point out, the models must have same dimension and I had to check them before attenpting to performe any math operation.

I followed the steps you provide me in the forum's replay and I got the map I was looking at.

The map doesn't look as I aspected because of the contaminant model. In fact the contaminat map is made by values in the I-data table. As you can see from the attached image section the contamination in S1001 is not limitend by a lower not contaminated sample. The resulting map yield to overstimate contamination in G2 materials.

Thank you.

Daniele

[Alison]

Hi Daniele,

If there is no data at a specific location (for example, at the bottom of S1001) to tell the program that no contamination exists, the program will use the closest concetration values to estimate the concentration at that location. I can think of a couple of suggestions for dealing with this:

1. You can place a low value at the bottom of the borehole S1001.

2. You might try experimenting with the "Distance Cutoffs" in the Solid Modeling Options window. If you were to specify a vertical cutoff of 2m, the program would not use points more than 2m above or below a model cell during interpolation. Instead it would look for control points at the same elevation in other boreholes to estimate the value.

Please let me know if you have other questions.

Thanks,

Alison

[Daniele]

I tried the Solid Modelin Options "Distance Cutoffs" - Vertical CutOffs Options, Map Units = 1.0 m or 0.5 m for the I-Data -> Solid Model.

These options are not avaliable in the Lithologyc -> Solid model. I only found in the Lithology Model Options -> Closest Point, the Distance Cutoff Filter but it seems to me that enabling and changing value affects only the xy solid model and not the z value.

I also tried to export the Lithological Solid Model to the Utilities Datagrid with Lithology > Export to XYZG File (with Sample at Regular Intervals set to 0.1, the z model depth resolution) and then buid a New Solid Model with the Vertical CutOffs Options as I did for the I-Data Solid Model.

Is there a quick way to do it?

Daniele

[Alison]

Daniele,

I don't understand why you would want to apply this type of modeling filter to the lithology model. My suggestions was really only meant to be applied to your contamination model.

Could you explain to me why you think that this is necessary for the lithology model?

The modeling algorithms used to create lithology models are quite different than the inverse distance methods used to create models of P-Data, T-Data and I-Data.

Best Regards,

Alison

[Daniele]

Hi Alison,

I understood that you were referencing on I-Data model.

In the attached image you can see 2 profiles.

The upper profile is obtained by 1) creating the lithological solid model (closest point) 2) exporting the solid model to XYZG 3) create a new Solid model with Vertical Distance Cutoff. In the lower one the same profile is obtained by the starting lithological solid model (closest point).

In the S1031 the gray material is interpolated correctly in the upper profile and not in the lower one, as it extends far under the lithology unit. I need to correct this anomaly (green arrow).

The profile from the Lithology Solid Model obtainend with Lithoblending algorithm doesn't show the anomaly, but I rather prefer the closest point algorithm.

I also need to correct the solid model to fill the differnce from the topographic surface (red arrow) and the material top elevation in the upper profile.

Regards,

Daniele