地质科技通报 (Mar 2023)
Reaction characteristics of low temperature oxidation of light crude oil with disoxidation air
Abstract
With the temperature and pressure effect, the composition change and oxygen consumption law of light crude oil and discoxidation air in Tahei North Block were studied. The static oxidation experiment of crude oil was carried out in a high temperature and high pressure reactor indoors to systematically study the oxidation effect of crude oil by disoxidation air with different oxygen content and different gas injection volume; the hydrocarbon was analyzed by chromatographic analysis, and the reaction gas was collected for gas analysis. The results showed that: ① The low-temperature oxidation reaction between crude oil sample and disoxidation air decreased the components above C21 and increased the content of light components below C13; ② The oxidation effect of crude oil increased with the increase of oxygen content, and the components in the reaction process corresponded to the "inflection point" in the front; ③ When the oxygen content was constant, the "inflection point" corresponding to the reaction remained unchanged by changing the oil-gas ratio; In the overall reaction process, the oxygen content decreased and then tended to be flat; ④ CO2 was generated in the process of low-temperature oxidation, and the CO2 content tended to be flat after increasing; ⑤At reservoir temperature (160℃), crude oil mainly involves two reaction thermal cracking and oxygenation reactions. The thermal cracking reaction is not related to the oxygen content, but to the temperature. The main reaction temperature is 160-200℃. Heavy components such as high-carbon asphaltene will be decomposed into saturated hydrocarbons. The oxygenation reaction is mainly aromatic hydrocarbon, and the resin oxygenation reaction will also produce asphaltene. When the two reactions exist at the same time, the content of asphaltene participating in thermal cracking is greater than the quality of asphaltene generated by oxygenation reaction aromatic hydrocarbon, which will lead to the decrease of asphaltene content.
Keywords
