The four Primary Rock Eval Parameters are:
1. S1 – Quantity of free or absorbed Hydrocarbons in rock.
2. S2 – Quantity of Hydrocarbons generated during Pyrolysis of Kerogen.
3. S3 – Quantity of CO generated during Pyrolysis of Kerogen.
4. Tmax – Temperature of maximum S2 Generation. Source: http://in.docsity.com/en-docs/Geology_Basics_-_Geology_-_Lecture_Notes_