Abstract: Abstract: In response to the problem that the basic properties of oxidized carbon and pyrolysis carbon generated in the in situ combustion of super heavy oil in Block Jin 91, Liaohe Oilfield and the in-situ combustion characteristics were not well understood, experiments on low temperature oxidation and pyrolysis of super heavy oil were conducted with reaction still, the composition of produced gas and the micro morphology, element content and thermogravimetric loss of coke were analyzed by gas chromatograph, field emission scanning electron microscope, energy dispersive X-ray spectrometer and thermogravimetric analyzer, and the activation energy of coke combustion was solved by iso-conversional methods (Friedman and OFW). The results showed that, after low temperature oxidation at250 ℃, the super heavy oil was partially converted into oxidized carbon; after pyrolysis at 400 ℃, the super heavy oil was converted into pyrolysis carbon and modified oil. The relative contents of oxygen and sulfur elements in oxidized carbon were significantly higher than those in pyrolysis carbon. The surface of oxidized carbon was characterized by the inter-melted of coke particles with different particle sizes, and the porous structure of oxidized carbon became more obvious with the increase of temperature. The surface pyrolysis carbon became irregular micro blocks, and many raised particles appeared on the pyrolysis carbon surface with the increase of temperature. The formation of oxidized carbon was helpful to establish combustion front; the combustion activation energy of pyrolysis carbon was lower, conducive to maintaining the stable propagation of the combustion front. The study provides a theoretical guidance for the in-situ combustion in super heavy oil development.

Key words: Super heavy oil, in-situ combustion, low temperature oxidation, oxidized carbon, pyrolysis carbon, coke, coking formation, Liaohe Oilfield