Burmesegeologist's Blog

PST software was developed by Petroleum software technologies (see www.pstware.com for more detailed) Copyright © Petroleum Software technologies

You can download the software from the “Geological Tool” from right side of the blog.

Their main products were Rt-mod, Sp-Mod & NNLAP which is commercial software. I will explain free software “Calculator” for step by step usage.

This tool was design to do quick-look interpretation of water saturation in your reservoir.

Installation:

You need to run as administrator for installing in windows vista. You can install normally in windows xp.

After installation process was finished, you can see PST software in system tray of your windows xp. You may not see in system tray of your windows vista and you need to run the program directly from C:\Program Files\PSTware\Pstware.exe

When you run the first time for PST software, you will see the program will comes up like the below image.

Click the “Go To Calculator” and It will comes up like this;

When you double click the Box next to respective parameter, it will explain more about the parameter. For example, if you double click the box next to Porosity, it will comes up like this;

You can calculate porosity from density log or sonic log, insert the appropriate value of bulk density, grain density and fluid density. It will calculate automatically the porosity value of your input point.

If you want to know more about the calculation behind the porosity, click “Reference” and you will see explanation of calculation behind and some reference paper were cited.

Example calculation:

Assuming below was your reservoir parameter;

Rt (true formation resistivity) =  30 ohm

Porosity   =   0.22

Rw (resistivity of formation water)  =  0.156  (assuming salinity 12000 ppmcl @ 150 ‘F)

a  =  1

m  =   2

n = 2

Your Bulk volume water is = 7.2 % and your water saturation is 32.8 %.

Reference cited:

Schlumberger (www.slb.com) is a good source of information for oil field related terms and abbreviations. You can see most of the information in

http://www.glossary.oilfield.slb.com/

http://www.slb.com/content/services/resources/books/index.asp?

For further reading about formation evaluation:

1. The Geological Interpretation of Well Logs (Second Edition) by Malcolm Rider
2. Log interpretation principles and applications by Schlumberger
3. Log interpretation charts by Schlumberger