A pyrolysis experiment with gold-tube modeling apparatus was carried out to study the features and kinetics of hydrocarbon generation from the type-Ⅰ organic matters in the Cretaceous lacustrine sequences

Songliao Basin.Quantitative analysis of the liquid and gas products from the simulation experiment of type-Ⅰ organic matters indicates that oil is the dominant product and gas yield is limited with the maximum value from the primary cracking at 100 mg per gram of organic matter.The chromatograms of light oils and the activation energy distribution of hydrocarbon gas genereation collectively demonstrate that the hydrocarbon gas in confined system are generated from multiple reaction processes

wherein the secondary cracking of liquid hydrocarbons initially generated have a greater contribution.Meanwhile

kinetics calculation shows that the reaction kinetic parameters of different liquid hydrocarbons differ from one another;the activation energy of light components is obviously higher than that of the heavier ones;the average activation energy of secondary cracking of residual oil in source rocks was 57.3 kcal/mol

being lower than that in normal reservoirs;and the generation of primary cracked gas from the type-Ⅰ organic matters lasted from the initial stage of oil generation to the early cracking stage of residual oil within source rocks.