Hello all,
Doing some work in a shale gas play, and have dervied regression relationships for PHIT and SWT from a number of different cores in the area. I now want to apply these equations across a larger area, but have quite a mix of different log vintages and service companies.
There is a non-organic-rich shale overlying the organic shale that I'm analyzing, and was hoping to use this to normalize my porosity logs. I'm plotting histograms of each log over a 75 metre interval of the non-organic shale. What I'm wondering is, would you just shift your histograms to match mean value "peaks" to what I consider to be the correct value (it seems to be consistent between the very modern wells). Or, should I also be shifting the "tails" of the histogram to get the histogram distributions to be more similar in shape? (i.e - pinching and stretching the histograms)
Resistivity doesn't look like it will be an issue because it's all running pretty consistently at 10 ohmm through the overlying shale, regardless of the age of the log. However, in the organic-rich zone, resistivity in some wells looks like it's reading beyond the tool maximums (some reading 20,000 ohmm). Are there good ways to fix extrememly high resisitivities like this? The only way I can think of is trying to rebuild a new
RT curve using multiple log regression from wells with good Res data, and applying to wells with problems after the porosity logs have been normalized.
Thanks for any help you can offer!!
