Guys, dry clay inputs is one of the most importat values when you use Dual waters equations( or similars), wet clays are easy (or not on DEN-CN xplots) but you must have an idea about dry clays ( default values of 2.78 on IP are focused on gulf sediments and still they are generally very high., for this values most of clays should be chlorite or other weight clays). Try to determine those values on core data withouth so high temperature of treatment and with controled humity ( no more than 85 Centigrades), it take more time and is more expensive, but if you expose your core data to more than that, it is posible you 'never know if it is total phi, effective or a mix value, the you for sure have been lost you money on this try. Another tiem expensing method is try to compare DW and Juhazs SW, the last use insted a RWbound value a comparison between dry and wet clay, if you have any data of RWbound ( not ever related to 1/phishale**2 relatioships) you should obtain on both formulae similar values. Regards and let me know yous experiences
MM (Euskadi 59)... Also constrains your values with less acuratte formulaes as Simandoux