Kinetics of Individual C1–C5 Hydrocarbons Formation of Domanik Shale in Hydrothermal Experiments

Abstract

Twelve hydrothermal autoclave experiments were conducted with Domanik oil shale from the Ukhta region (Chut River) at temperatures of 250–375°C and run duration of 24 h (6 experiments), 72 h (5 experiments), and 48 h (1 experiment). The composition of hydrocarbon gases C₁–C₅ was studied for each experiment and quantitative data on their yields were obtained. Based on these data, the distributions of generation potential of individual gaseous hydrocarbons by activation energy were established under hydrothermal experimental conditions. The character of the kinetic spectra of individual alkanes C₂–C₅ is virtually identical; their main narrow maximum corresponds to E_a 55 kcal/mol with an Arrhenius factor of 1 × 10¹⁴ s^–1. The distribution of the methane generation potential by activation energies is distinguished by the fact that a significant part of its generation potential falls within the region of activation energies of 60–70 kcal/mol and by the uncertainty of the distribution character in this region.