Kerogen transformation to petroleum and thermal maturity modelling calibrated to vitrinite reflectance utilizing Arrhenius-equation reaction kinetics are important oil and gas exploration tools for conventional and non-conventional resources. The range and correlation between activation energies (E) and frequency factors (A) on a geological scale is presented to support the theory and application of the time-temperature index (∑TTIARR) method of thermal maturity proposed in 1988, with a single set of E-A values (E = 218 kJ/mol (52.1 kcal/mol); A = 5.45E+26/my). The ∑TTIARR method provides a highly-sensitive and transparent thermal maturity index. It is well-correlated with vitrinite reflectance and produces comparable results with models applying theoretically-tenuous distributions of E with single A values. The sensitively-scaled ∑TTIARR methodology has the added benefit of providing detailed insight to petroleum generation via the calculation of related transformation factors (TF) for oil and gas, by applying a range of E-A values referencing the ∑TTIARR thermal maturity scale as a benchmark. This study provides analysis of detailed modelling of the transformation process with representative and realistic kinetics for kerogens, and mixtures of kerogens, for a wide range of heating rates at geological and laboratory scales. The results reveal that novel metrics (such as, maximum transformation gradient and temperature at which it occurs, average transformation gradient between 10% and 90% conversion, and temperature spread from 10% to 90% conversion) can discriminate between the transformation processes of kerogens, and mixtures of kerogens, at geological and laboratory scales. These metrics offer the potential to more-precisely define “sweet spots” of petroleum generation in organic-rich shales. They also have potential at the laboratory scale to assist in the extraction of kinetic information from existing and future pyrolysis test. Furthermore, the analysis suggests that mixtures of kerogens can, in most cases, be more effectively identified and characterized, and their petroleum transformation modelled, with just two or three E-A sets as kinetic inputs. This approach is preferred to the common practice of using a complex distributions of multiple E values linked with a single A value unrelated to the geological-scale E-A trend established for kerogens.