Another classification according to the kind of kerogen, relies about the hydrogen, carbon, and oxygen written content of the first natural subject in the oil shale. This classification is utilizing the Van Krevelen diagram.[6] Probably the most made use of classification of oil shales was formulated involving 1987 and 1991 http://louisczzws.educationalimpactblog.com/16247122/5-simple-statements-about-geosteering-explained