!!! FREE SOFTWARE !!! Have some logs in front of you, either on paper or just images on your computer screen? Did they come in from the rig only moments ago and your Exploration Manager is looking over your shoulder and wants to know what he’s found? You’ve got no digital data, but you want to get a quick idea of a couple of basic rock parameters like F and Sw? Or, maybe you just don’t have the time to load the digital files into your favorite petrophysics application... Maybe these simple log data calculators can be useful. I’m afraid that they do not do advanced log analysis... just simple point-by-point calculations. But they are free. In each case, just click the link in order to save the executable file to your disk.     Porosity Calculator does density and sonic porosity calculations. Archies_Calculator does simple Archie water saturation and RWA calculations. Antique_Neutron_Tools estimates porosity using the appropriate chart for a variety of “antique” neutron logging sondes, including Schlumberger,PGAC, Birdwell, Welex, Lane-Wells, and Gearhart-Owen tools. Salinity_Calculator-Revised estimates brine salinity from Rw and temperature, or Rw from salinity and temperature.  Convert is a units conversion program that I’ve found to be very useful. I didn’t write it; the author’s website is www.joshmadison.com. DISCLAIMER These executables are offered free of charge and “as is”, with no warranty of any sort made or implied. The validity of any results obtained from them, as well as any consequence of the use of these executeables, is the sole responsibility of the user. A FEW GOOD LINKS www.spwla.org Society of Petrophysicists and Well Log Analysts www.spe.org Society of Petroleum Engineers www.slb.com/ Schlumberger www.bakerhughes.com Baker Hughes www.ogec.com Oil & Gas Evaluation and Consulting www.banksgeoscience.co.uk Banks Geoscience www.logwell.com Analog Services, Inc. www.wellog.com/ Wellog - This site includes a good overview of log analysis Odds & Ends - A few more good links, and some video clips, too...