In geoelectrical survey using Schlumberger Configuration, also known as Vertical Electrical Sounding (VES), there is a principle of inversion. Inversion is converting the value of apparent resistivity using a transformation function related to layer parameter through algebraical relation to obtain true resistivity value. The advancement of computer technology brought about various Schlumberger resistivity interpretation software that could perform the interpretation automatically.
However, automatic interpretation was not enough. Theoretically, if two successive apparent resistivity values are drawn onto logarithmic plot and the resulting slope is greater than 45°, then the data were distorted (Damtoro, 2009). Distorted data needed to be corrected to provide more accurate result, while most existing interpretation software could not mark out distorted. In addition to this problem, interpretation of relatively large numbers of VES data took large amount of time. This was due to the fact that most interpretation software processed the data one point at a time.
Regarding those problems, the authors attempted to address the drawbacks of existing software by adding automatic correction feature and massive VES data processing. With this software, interpreters could cut the processing time and obtain more accurate result.
This software was named ‘MARAI-1D’, it stood for ‘Massive Resistivity Auto Interpreter – 1 Dimension’. The advantages of this software were:
- Automatic interpretation of resistivity data without initial layers and thickness assumption.
- Automatic data correction, so that no data is distorted from the curve.
- Simultaneous data processing of up to 10,000 points*.
- Presenting interpretation curve and 1D cross-section layer for every survey point.
- Showing map of survey location points.
- Showing semi-2D cross-section correlation of chosen points.
- Showing in colors the layers’ cross-sections in logarithmic and linear scale.
- Importing and exporting MS Excel 2003 and 2007/2010 files (.xls & .xlsx)
- Mass illustration file export to .bmp, .gif, .jpg, .png, and .emf extensions.
- It’s FREE!**
This software runs on PC with following minimum requirements:
- Windows OS (also runs on virtual PC, like VirtualBox, VMWare)
- Microsoft .NET Framework 4.0 Client Profile
- Windows Installer 3.1
- Microsoft Office Excel 2003 and 2007/2010 (for import & store file)
To download MARAI-1D for free, CLICK HERE (‘Save As’ won’t work)
*Theoretically. Not tested yet.
**This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.