Kinetic modelling of oil cracking

The effect of oil expulsion or retention on further thermal degradation of kerogen at the high maturity stage: A pyrolysis study of type II kerogen from Pingliang shale, China

“…Relatively lower HI in residual solids of KO compared to that in the residual solids of KAE at the pyrolysis temperature of 384°C could be explained by the reduced formation of pyrobitumen due to the oil expulsion. Pyrobitumen is mainly derived from aromatic condensation of oil or bitumen (Ungerer et al, 1988;Behar et al, 1992;Schenk et al, 1997;Hill et al, 2003).…”

“…It could involve multiple order reactions, but for convenience in exploration, the generation process was usually simplified and described as multiple parallel first order reactions (Ungerer et al, 1988;Behar et al, 1992;Horsfield et al, 1992;Schenk et al, 1997;Waples, 2000). Non-isothermal experimental data were mostly used to produce the distribution of activation energies and model the complicated hydrocarbon generation from the decomposition of kerogen or oil.…”

Retardation of oil cracking to gas and pressure induced combination reactions to account for viscous oil in deep petroleum basins: Evidence from oil and n-hexadecane pyrolysis at water pressures up to 900 bar

“…Price et al, 1979;Price et al, 1981;Price, 1982;Mango, 1991;Hayes, 1991), laboratory pyrolysis investigation of oils (e.g. Ungerer and Pelet, 1987;Ungerer et al, 1988;Behar et al, 1992;Behar et al, 1997a;1997b;Schenk et al, 1997;Dieckmann et al, 1998;Lewan and Ruble, 2002;Hill et al, 2003;Lehne and Dieckmann, 2007a;2007b;Behar et al, 2008), or theoretical calculations (e.g. Dominé et al, 1998).…”

“…Undegraded crude oils generally show an increase in both API gravity and gas to oil ratio (GOR) with increasing depth of burial (Tissot and Welte, 1984), which can result from the conversion of oil into lighter hydrogen-rich products (gas and condensate) and heavy carbon rich solid residues (coke or pyrobitumen). Pyrobitumen forms either by aromatic condensation reactions (Ungerer et al, 1988;Behar et al, 1992), or directly from nitrogen sulphur and oxygen (NSO) compounds (Hill et al, 2003). Oil cracking to gas was described as occurring via hydrogen transfer reactions (Bailey et al, 1974;Connan et al, 1975), although it also appears that the mechanism involves free radical reactions (Rice and-Herzfeld 1934), with initiation, hydrogen transfer, decomposition of carbon-carbon bonds by ß-scission, radical isomerization, addition and termination processes in the oil (e.g.…”

Evaluation of residual oil content, composition, and evolution of marine shale from the Middle Ordovician Pingliang Formation, Erdos Basin, China

“…Recent studies and explorations have shown great potentials of unconventional oil gas resources such as shale gas and shale oil, which shows important roles of retained hydrocarbons in source rocks. Numerous studies have been conducted to determine how oil composition changes with thermal stress on the kinetics of kerogen and oil cracking (Bjorøy et al, 1988;Ungerer et al, 1988;Behar et al, 1991;Behar et al, 1992;Horsfield et al, 1992;Kuo and Michael, 1994;Pepper and Dodd, 1995;Schenk et al, 1997;Tsuzuki et al, 1999;Hill et al, 2003), but the evolution of residual oil and its fractional compositions in the process of maturation for whole rock has not been intensively studied.…”