oa Classification and discriminant functions of alpha- beta radioactivity parameters in oil and gas geophysics

The specific alpha and beta activity (Aα and Aβ, respectively, in Bq / kg) of core samples from sedimentary rocks of Runovshchyna area (Ukraine, Poltava region) were performed in during of the petrophysical investigations. The active role of sulfur, water and chlorine was revealed by regression model of Aα from the composition. These components are responsible for changing the redox conditions under which uranium is immobilized. As well K2O and H2O are leading component affecting the Aβ. The factorial experiment of regression coefficients revealed its interrelated influence but only H2O can be formally considered an independent feature of model. The ratio Aα:Aβ can be used to classify the clastic rocks. The сlaye of sandstone is better efefcted in Aβ values rather Aα. Sandstones without of the obvious claye/carbonation evidances have the Aβ value of 816, whereas in clay varieties the average value is 1924. Carbonated sandstones, on the contrary, it decreases slightly to 803. Samples of rocks with a high content of carbonized residues usually have negative correlation between Aα and Aβ. The proposed discriminants and classification dependences of Aα and Aβ can be used as independent geophysical parameters for exploration purposes of oil and gas geology.